Living with Volcanoes
“_He took his journey into a far country._”
The next decade began true experiments with volcanoes, when two
organizations some 5,000 miles apart combined their resources. The
Whitney Foundation created at Massachusetts Institute of Technology an
endowment of $25,000 for geophysical work on earthquakes and volcanoes,
expressing a preference for work in Hawaii; and a group of businessmen
in Honolulu, the Volcano Research Association, offered to pay my salary
for five years.
When President Maclaurin and a group of professors at M. I. T. gave me
a dinner at the University Club in Boston to celebrate my departure for
Honolulu, the dinner table conversation turned to the terrors of the
deep sea, the dangers of volcanoes, the awfulness of leprosy in Hawaii,
and the heroism of giving up a secure teaching job in Boston. I replied
that their pessimism reminded me of the last words of Daniel Webster,
as quoted by a New England farmer, who said “Dan’l opened his eyes,
took one look at the glass of whiskey on the table at his bedside,
another at the pretty nurse, and said ‘I ain’t dead yet.’”
I had organized the funds available so that a pair of Bosch-Omori
seismographs were shipped from Strassburg, and other seismographs
were ordered from Omori’s instrument maker in Tokyo. I collected
experimental instruments such as high temperature thermometers and
chronographs, of the type used in experimental physiology. Vaguely,
I was going to take the blood pressure and pulse of the globe. Also
I obtained a full set of weather bureau instruments for temperature,
rainfall, barometric pressure, and humidity, together with the electric
pyrometers, range finders, and photographic apparatus used in my
previous expeditions. And I had some small Japanese transits, as well
as plane tables and alidades for topographic experiments.
I was unable to go to Hawaii until 1912, so I was delighted when
Perret consented to go to Kilauea Volcano in company with E. S.
Shepherd, gas chemist of the Carnegie Geophysical Laboratory of
Washington, in the summer of 1911. Dr. A. L. Day, director of the
Carnegie laboratory, kindly supplied at our expense two Leeds and
Northrop resistance pyrometers and the accompanying Wheatstone bridge,
as well as thermocouples loaned from his equipment. Perret and Shepherd
went to Kilauea Volcano House; and Perret built a hut at the edge of
Halemaumau pit, where an inner lava lake was bubbling and maintaining
an island some 200 feet below the rim. Kilauea is the big cauldron,
Halemaumau is the firepit in its floor. “Kilauea” activity generally
means Halemaumau. They have separate cliff margins.
L. A. Thurston, leading journalist and publicist of Hawaii and keen
promoter of a proposed Hawaii National Park, did everything possible to
help the scientists. Perret wrote weekly reports on the condition of
Halemaumau lava, and sent in photographs to Mr. Thurston’s newspaper,
the _Pacific Commercial Advertiser_. Living and camping at the
fire pit, Perret inaugurated something new for Hawaii, and set a
standard for the Volcano Observatory. These continuous reports had been
my dream for such volcanoes as Vesuvius, where publication had usually
been in delayed annuals and gave no current news of what the volcano
was doing. Furthermore, the Vesuvius observatory was at the foot of the
peak.
I had ordered from the Lidgerwood Company an equipment of cables,
including some containing electric wires. These were to span the 1,500
feet and to lower a thermometer into the pit of Halemaumau. Assisted by
Alex Lancaster, the active little half-breed guide from Virginia, and
by numerous laborers from the plantations, whose managers, spurred on
by Thurston, took a great interest in the project, Perret and Shepherd
erected two high A-frames on opposite sides of the fire pit and built
a trolley on the cable stretched between them. Perret kept constant
angular measurement of the changing height of the liquid lava, as the
glowing slaggy pool rose and fell overflowing its banks. At one side
of a triangular island was a point of ebullition called “Old Faithful”
where gas bubbles burst in a fiery dome, irregularly, but approximately
once a minute. The objective was to find the temperature of the liquid
lava in the vicinity of the bubbling. This was achieved by actually
dipping the electric pyrometers into the molten slag, then observing
the precise temperature at the recording box, which was in the hands
of Dr. Shepherd, who remained on the pit rim at the upper end of the
connecting wires.
Finally the day came, after numerous rehearsals, when the long steel
tube, or terminal, on the end of the movable cable could be moved out
by the trolley to a middle point over the pit, where it would make
contact with bubbling liquid lava when lowered. This was an extremely
ticklish procedure, for the lava was a heavy mat of self-crusting
liquid rock with the crust forming hard slabs; few places kept up an
appearance of bubbling porridge. No one had ever made contact before
with the liquid of a fountain like “Old Faithful.” It was fortunate
that the apparatus, which was expensive, consisting of platinum wires
imbedded in silica glass, was made in duplicate so that we had two of
everything. The splashing liquid of “Old Faithful” looked as harmless
as a kettle of boiling soup, but Perret and Shepherd were in for a
surprise. When Shepherd lowered the terminal directly into the liquid,
“Old Faithful” exploded, for the molten slag proved to be a suction
whirlpool which threw tentacles of lava over the steel pipe. The
apparatus went down to destruction “like a bass under a log,” and the
cable was bitten off like a piece of line. The entire terminal vanished
into the vortex, leaving only a corroded wire.
To shorten a long story, the second terminal was lowered into a
seemingly safer liquid place. A wave of the melt slapped and strained
the pipe, and though it was recovered, no electric resistance reading
was obtained at any time with the box at the rim of the pit. Close to
$1,000 in equipment was lost. The resistance pyrometer is a sensitive
tool in the laboratory, for giving precise degrees of temperature in
the region of 1200° Centigrade, supposedly the melting point of basalt.
But it was unsuited for the rugged bubbling of basalt slag, where
flaming gases and chilling air play more important parts than mere
melting.
Fortunately Shepherd and Perret were not at the end of their resources.
There still remained the thermocouple, a simpler pair of wires of
platinum and iridium encased in a steel tube. The connectors from these
go to a simple galvanometer in the hands of the operator. The trolley
could still be used, and the thermocouple pipe had no glass inside it
to be shattered. A temperature of 1000° Centigrade was recorded in a
bubbling area, and this was considered good enough for an approximation.
Another experiment was to lower an iron bucket into the liquid, and
pull it up full and dripping with black lava glass. This was sent off
to Washington for analysis. Afterwards the lava lake went down, no more
experiments that year were possible, and Perret began the plotting of a
curve of high and low in the rise and fall at the bottom of the pit.
It may seem extravagant to waste valuable apparatus on such seemingly
small results; but as a matter of fact, the Shepherd-Perret journal
of the summer of 1911 was epoch-making in the history of volcanology
and in the work of the Hawaiian Volcano Observatory. It proved that
skilled observers could dwell inside an active crater and there apply
their skills in photography, chemistry, note-taking, and continuous
publication. The substance of active lava lakes was proved to have
viscosities and solidifications quite different from those implied
by gases, and it was shown that different types of thermometers
gave negative or positive results useful for the future. Above all,
the notes on volcano chemistry by Shepherd and Perret demonstrated
that engineering apparatus could be applied to the hottest and most
continuously active pit in the world. Their success was at the
relatively small expense of a journey and a few machines. Brun of
Geneva had set an example of similar work, but Perret’s curve of rise
and fall added a more detailed record of the Kilauea pit from day to
day than had ever been made before.
An observatory is a place of observation and measurement, whether the
things observed are glaciers, rivers, stars, the weather, or volcanoes.
The motive of observation in modern science is either the quality of
what happens or the quantity expressed in lengths and degrees and rates
of speed. Remembering the precedent of Vesuvius, I was confronted
in Hawaii with the necessity of determining how a volcano should be
observed, the need to measure changes in a single volcano, and the need
for permanent records of what those changes are. We chose measuring
instruments, photographic equipment, and thermometers, and I invented a
note-taking system which was compiled into a single record book, from
field notes taken uniformly by many different assistants.
[Illustration: _7. Volcano House from Observatory, 1913_]
[Illustration: _8. Island in Halemaumau lava lake, 1911. Photo
by Perret_]
[Illustration: _9. Hawaiian Volcano Observatory, 1912_]
[Illustration: _10. Jaggar in seismograph vault beneath Volcano
Observatory, 1916_]
The textbook needs for volcanology are records of the shape, height,
number, distribution, temperature, and differences among volcanoes. How
gaseous is lava? how radioactive is it? how often does it erupt? and
how dangerous is it for human beings? With reference to the source,
crack or crater, we need knowledge of how the earth crust is ruptured,
how deep are the fractures, and how much accompanied by earthquake
is the wedging upward of lava in those cracks.
My first job on arriving in Hawaii was to make contact with Mr.
Thurston and his associates. The next was to get a good map made of
Kilauea Volcano as a basis for measurement of changes in the fire pit.
Governor Walter F. Frear came to my rescue and immediately sent Colonel
Claude Birdseye and Captain Albert Burkland to make a topographic map
of the proposed Hawaii National Park. These engineers brought into the
field the topographic camp of the U.S. Geological Survey, and they were
extremely sympathetic with my project, furnishing me with surveying
monuments, and sketching out methods wherewith to make an accurate base
line for measurement of changes inside the pit.
A laboratory on the northeast edge of Kilauea Crater was quickly
provided through the energy of the brilliant Demosthenes Lycurgus,
hospitable Greek manager of the Volcano House, the hotel where I
stayed. All the merchants of Hilo, thirty miles away, contributed funds
and in a few weeks carpenters were at work, on land belonging to the
Bishop Estate and sublet by the Volcano House. Furniture was paid for
by the Whitney Fund.
A cellar for seismographs was blasted by Territorial prisoners in
the hot rock under the laboratory, at the actual northeast edge
of the greater crater of Kilauea. The lava pit Halemaumau, always
smoking, was in full view two miles away. The cellar lined with
concrete, which shut off the steam cracks, became a warm, dry place
for instruments at a constant temperature of about 80° Fahrenheit.
Concrete tables on the floor of the cellar held the pair of east-west
and north-south horizontal pendulums, recording with delicate pens
on smoked paper, stretched over a chronograph drum. These paper
records, removed every day and fixed with shellac varnish, became the
seismograms of the permanent files. Long belts of wavy lines on each
paper exhibited seconds, minutes, and hours; and when a sharp zigzag
in one of the lines occurred, it was evidence of either a local or a
distant earthquake. H. O. Wood, who had been my assistant in field
geology at Harvard and had had experience with Omori seismographs
at the University of California, was summoned to the Observatory as
seismologist.
Thus in the first six months of 1912 I became a resident of a volcano
in Hawaii and had an adequate laboratory of eight rooms, and suitable
porches, a darkroom for photography, and the beginnings of seismograph
records in the basement. Horses and saddles were purchased, the
necessary outer houses were built, and Alec Lancaster was employed as
janitor and field man. Francis Dodge, athletic young Honoluluan and son
of a government surveyor, was appointed topographic assistant. He was a
hardy cowboy, with some experience as rodman for the Geological Survey.
From the moment of my arrival I adopted uniform pocket scratch pads
with detachable sheets for the use of all employees, insisting that
anyone who went to the lava pit should write notes, inscribe the
date and hour, tell what he saw, and hand the notes to me. Even Alec
Lancaster, whose father was a Cherokee Indian carpenter and whose
mother was a mulatto, took notes and learned about the points of the
compass and the names of the coves and blowholes of the lava lake in
the bottom of the pit. Some of Alec’s notes were very amusing, as when
he wrote, “9:30 A.M. April 3, Old Faithful is on her job right
sturdy.” However, he quickly learned the correct technical expressions
for surface streaming of the lava, brightness of the fountains at
night, numbers of the bubble fountains, and places of smoke on the
bottom of the pit. At all times Alec was a useful camp man, a good
cook, and a fearless climber of cliffs. When it came to making and
using rope ladders with hickory rungs for descent down a 200-foot cliff
to the edge of the lava, Alec was the first to volunteer. He drove
spikes into cracks in the rock and tested out the ladders, surrounded
by smoke. This was done in June and December of 1912, when the gas
chemists of the Carnegie Institution were conducted to the bottom to
collect gases, by pumps and vacuum tubes, from flaming spatter cones.
I hope this introduction gives some idea of what the first year of
the Observatory accomplished. Meanwhile problems of policy and of the
publishing of results crowded upon me thick and fast. The notes of all
employees had to be compiled; critical scientific visitors had to be
convinced of the usefulness of the new effort; the Massachusetts Tech
and Honolulu sponsors had to be given suitable reports; a permanent
record book, reproducing surveys, notes, and photographs, had to be
devised; and I had to make occasional journeys to California, Boston,
and Washington for contact with the Government, with scientific
societies, and with scientific magazines.
It was necessary to keep track of improvements in photographic plates,
for the fire pit with its dark red heat and dark red rocks was a
difficult subject for photography. Fortunately, the panchromatic plate
had recently been invented by Dr. C. E. K. Mees, and was a godsend for
experiments in recording liquid lava splashing at night. Dr. Mees,
chief of research at Eastman Kodak Company in Rochester, has since
been a visitor and good friend of the Observatory. Both surveying and
photographing were difficult during 1912 because the inner pit sent up
a dense column of fume which diminished only at those times when the
liquid lava became hotter and developed fountaining. There was such
smokeless development with hundreds of roaring fountains of liquid lava
in January and July. The intervening period showed a great deal of
smoke, and in August there was a dense column of silently rising gray
fume the full width of the pit, so that nothing of the bottom could be
seen.
To determine the height of the bottom lava it was necessary to work
from a fixed station with a transit, using a flashlight at night, and
waiting for a view of a glowing spot or fountain. This involved reading
vertical and horizontal angles, dependent on difficult determination
from two stations, of the distance to the glow spot measured. Often
in daytime one had to wait hours in order to get a view of the bottom
through the fumes, from stations at the ends of a base line on the edge
of the pit. At no time later, fortunately, were the fume conditions
so bad as during 1912. A procedure was adopted of making a daily
photograph of the smoke of the distant pit from the window of the
observatory, and this proved of value when the inner lava lakes and
crags rose to view in 1917.
Like Perret, I made reports to the newspapers in Honolulu; and
gradually these reports took the form of a monthly bulletin, edited
in Honolulu by Dr. Howard Ballou, who was the secretary of the
Hawaiian Volcano Research Association. This association had occasional
Directors’ meetings, which I attended and before which I made reports
and gave lectures. The report of the complete work done during
the first few months of the year 1912 was published in Boston by
Massachusetts Tech.
The earlier history of Hawaiian volcanoes had been recorded in
excellent books by such travelers as the Misses Gordon-Cumming and
Isabella Bird, William Lowthian Green, and Drs. C. H. Hitchcock and
W. T. Brigham, and Professor James D. Dana of Yale. Dana had been
furnished with data from 1840 to 1890 by a Hilo missionary, Titus Coan.
When I arrived in Hawaii, two books on Kilauea’s activity in 1909 had
just been published, and a big monograph by Brun of Geneva who had
determined that Kilauea lava was free from water vapor and was the
hottest lava in the world.
Furthermore, R. A. Daly of Harvard had published his “Nature of
volcanic action” on the basis of his summer at Kilauea in 1909. There
was strong controversy against Brun on the water question, but the
experts, including Day and Shepherd, came to the conclusion that
lava eruption of the Kilauea type was actuated by such flaming gases
as hydrogen, carbon monoxide, and sulfur; that these gases were in
solution in some elemental form deep down in the earth; and that the
chemistry of their emission heated the lava on its way up. The lava
lakes were hotter at the top than at the bottom. We shall see that all
lava partly solidifies at its own bottom and stays liquid above.
The items of activity at Kilauea Volcano during the decade from 1911 to
1920 were marked fluctuation up and down in 1912–1913, with a notable
low level in 1913, culminating in a strong earthquake in October. In
1914 the liquid lava came back into the bottom of Halemaumau pit, and
in December Mauna Loa erupted in a fountain at its summit crater. The
lava lakes of Kilauea grew bigger in 1915, and a triangular island
appeared, lifting itself up from a shallow flat and even rotating or
hinging horizontally. Its uplift was as a peaked escarpment of lava
layers tilted in one direction, something very like Perret’s island of
1911.
An affinity between Kilauea and Mauna Loa was obvious. In 1916 Mauna
Loa completed its summit gushing by splitting open the mountain’s
southwest rift and making a lava flow into ranch and forest lands of
South Kona. But just as Mauna Loa activity ended, the entire Halemaumau
bottom thirty miles away lowered dramatically during one day, leaving a
deep seething puddle of melt, surrounded by roaring red hot avalanches.
The coincidence, along with appropriate earthquakes, was unmistakable.
Immediately after the lowering, the liquid lava of Halemaumau welled up
border wall cracks and cascaded through the talus to form an oval pool
in the bottom funnel of broken rock. The lava column rose 600 feet in
the next six months and a lobate lake developed, its coves separated
by sectors of overflow lava which lifted slowly into crags in the
center. In 1917 the lakes and crags inside Halemaumau were less than
100 feet down, the lake shores became accessible for experiments with
iron pipes, and the crags came into view from the Observatory, fully
justifying the daily photograph for comparing changes of the distant
pit.
[Illustration: _11. Lava lake, showing bench, March 30,
1917_]
[Illustration: _12. Halemaumau, showing lava lake and crags,
December 8, 1916_]
[Illustration: _13. Jaggar holding pipe for sounding lava lake,
1917. Cylinder on end of pipe holds Seger cones for measuring
lava temperature_]
By 1918 and 1919 the pit was full and overflowing the Kilauea floor.
During the whole of 1919 Halemaumau, as a pit, was obliterated by its
dome of fill. In autumn the south flank of Mauna Loa broke out again,
into a flood of lava that reached the sea in South Kona. Remembering
1916, we predicted that, even though Halemaumau was full to the brim,
the sinking away of Mauna Loa lava would pull down Kilauea lava
suddenly, like a siphon. Exactly this happened on November 28, 1919.
During the night the crags, the clover-leaf lake, and the bulging
dome of the lava fill above Halemaumau’s edge went down as a cylinder
to a depth of 400 feet in two or three hours leaving incandescent
avalanching walls, a gratifying confirmation of theory.
As in 1916, the Halemaumau lava immediately returned to the bottom of
the pit, and lifted itself thirty feet a day for three weeks, so that
in December it was a violently boiling ringshaped puddle, surrounding
a horseshoe of crags with a quiet inner lagoon and resembling a coral
atoll. The Kilauea floor, which is dome-shaped outside of Halemaumau,
split open radially to the south, made floods of lava into the Kilauea
Crater wall valley, and even escaped out into the Kau Desert. This was
extended into a mountain crack, making flank lava flows of Kilauea
Mountain, nine miles away to the southwest, something which had not
happened since 1823 and 1868. Concentric craters like Kilauea caldera
and Halemaumau pit are thus ring-in-ring, or cup-in-cup, structures
by means of slag heapings over a deep fracture in the rock crust, the
circularity determined by occasional central sinking.
This circularity has sometimes reached perfection. In 1894 and 1909
the liquid pool inside Halemaumau, by steady welling up about a
central hole, became perfectly circular within a circumferential
rampart of overflow. This is a rare condition dependent on steadiness
of upwelling, temperature, and viscosity. It is important because it
shows how the perfect circles, and rampart cauldrons, were made on the
moon, where there are also angular calderas of subsidence like Kilauea
Crater. Evidently gas heating and liquidity changed on the moon, just
as it has done in Hawaii. The sources there are over cracks, as in
Hawaii. The analogies are so complete in these and many other ways that
I completely disbelieve in meteor impact for the moon craters. The moon
awaits a complete comparison with active terrestrial basaltic lavas,
by a modern volcanologist.
This is only a thumbnail sketch of the astonishing luck which met the
photographers and note takers of the Hawaiian Volcano Observatory
in its first decade. There were similar decades in the nineteenth
century, and there were similar jagged crags rising as islands and
shorelines around clover-leaf lakes in 1879 and at other times. There
were undoubtedly earlier similar sympathetic movements whereby Kilauea
had lowered following the end of Mauna Loa outbreaks. But none of this
had ever before been measured from day to day. Our staff from 1912
on occupied the trig stations, every day or night when the weather
permitted, in order to measure within one foot the level of the live
lava up or down. The lava was like the mercury in a barometer and
needed incessant watching. This was done with a telescope, by people
who dwelt on the edge of the vertical pipe. After 1913 the measurements
clearly showed that sinkings were just as important as risings. They
proved that the solid overflow matter and slide-rock slopes around the
edges of lava lakes and coves measurably were a paste. This containing
bank rose and fell at a different rate from that of the gassy liquid
which streamed and fountained inside. The compiled results showed that
the source of the liquid streaming was always at the west side of the
pit bottom and that the streaming was toward fountaining grottos at
the east. The liquid might at any time overflow its banks or sink down
leaving inner cliffs, by failure of full supply up the west wall crack.
All of this may sound highly technical; but notes, photographs,
seismograms, records of weather, and unceasing press releases and
reports to the sponsors, while difficult for literary description,
created a new technique. Science, when one is devising a new approach,
consists of observation first, of experiment second, and of explanation
or theory third. Something of that order has to be followed in the
record of a scientist’s life.
The surprising sympathetic lowering of Kilauea following the end of
Mauna Loa eruptions was only one of numerous surprises during the first
decade of the Observatory. For instance, the temperatures of hot cracks
were repeatedly and systematically measured, and nothing sympathetic
with lava motion was found. The same may be said about the weather.
At the beginning it was supposed that rainfall, air temperature,
barometric pressure, and possibly fluctuation of the trade wind, would
affect the volcano. However, the only quickly evident effect was the
visible vaporing of many cracks on the Kilauea floor which dried up and
diminished when the sunshine appeared, becoming dense and increasing
in cold or wet weather. This obviously meant that the moisture content
of the vaporing cracks, some steam, but mostly moist hot air came from
shallow rain water a short distance underground.
An effect that was more volcanic, but similar in principle, was the
visible vapor inside of Halemaumau, close to the lava lakes, which
always increased when the lava lowered and let the groundwater seep
inward. These visible vapors dwindled when the hot slag bubbled and
rose, and acquired a brighter glow. No steam vapor rose from the
glowing lakes. There was drying up of groundwater by increased volcanic
heat, just as the cracks of the bigger crater had their moisture dried
by the action of sunshine.
I shall have more to say on the subject of the seasons, the calendar
effects on the plat of rising and falling lava, and especially the
solar equinoxes and solstices. There appeared the hint of a daily
tide-like rise and fall of the lava in the pit.
Finally, there arose the question of counting earthquakes, measuring
their spacing in time and place, and seeing which belonged to Mauna Loa
and which to Kilauea fault rifts. We had to plot earthquake frequency
and size in relation to lowering lava, to day and night or to the
seasons. The study of rhythmic swelling and creaking inside the great
pasty mountains became an exciting quest. It gave promise of cycles
from the hours of the day to the decades of the century.
We also discovered, by measuring vertical angles, that the inner floors
rose and fell differently from the liquid lakes, hence the floors
could be called the bench magma, as distinct from the liquid magma.
This led to a bold experiment in 1917 when the liquid lava lakes
became accessible, after a casual visitor, Mr. Walter Spalding of
Honolulu, discovered an easy path down to the overflow floors at the
edge of the north lake. Here the streaming slag rushed toward a glowing
grotto, built up by spatter of a border fountain into a huge half-dome
containing a glowing cavern hung with stalactites on the shore of the
lake. The platform outside of the grotto was overflowed, and built up
as the liquid lake rose, the platforms of overflow sloping away to
the wall valley under the pit cliff. Thus the lake was at the top of
an inner dome a thousand feet across, just as Halemaumau pit rim was
at the top of an inner dome of Kilauea floor three miles across. The
outer edge of Kilauea Crater is a big oval at the top of the outward
sloping greater dome of Kilauea Mountain forty or fifty miles across.
When a little conelet formed on the northern or western floor platform
inside Halemaumau, its slope around a splashing and fountaining crack
would make a fourth innermost dome a few feet across in the series
of progressively smaller cone-in-cone structures from the outer rim
of the big mountain inward to the Halemaumau centers of eruption. We
saw such a conelet cave in just where I had stood and tested a flame
the day before. Quietly the cone collapsed into a fountaining well of
boiling lava beneath. The ring-in-ring conception must be held in mind
with regard to any volcano, for one thing which we discovered is that
cones are not only built up and collapsed but they are also swollen
up by internal percolation of cracks and expansion of the hot stuff.
This tumefying, or swelling, is concerned with the experiment now to be
described.
Even after Perret described his “floating island” of 1911 and I saw the
triangular islands appearing like shoals in a mud flat and gradually
rising into crags in 1916 and 1917, I remained incredulous of the
possibility of a basaltic island floating. When solid lava cracked
off in pieces from inner cliffs around the lava lakes, the fragments
immediately sank. Furthermore, when solid crusts formed on top of the
foaming and streaming slag, the shells, when they got thick enough,
cracked up, tilted up, and slid down and foundered in the melt beneath.
It was obvious that lava rock is heavier than lava foam. Hence as an
island is a rock, it would not float. This raised several questions.
Where was the bottom of the lava lake on which it rested? Did the lava
lake have a bottom, and if so how far down was the bottom when the same
lake rose 600 feet in Halemaumau pit between June and December of 1916?
In other words, was the lake 600 feet deep in December?
What would be the answer at any time if a stiff iron pipe were thrust
down vertically into the liquid lake as a sounding rod? No one had ever
raised the question. Cross-section drawings had always depicted the
liquid as extending downward indefinitely within a vertical tube. When
the lake became accessible in 1917, it seemed to me that a long steel
pipe might be shoved over the border rampart, end on, and allowed to
bend and sink, or to strike bottom. If the pipe could be recovered by
dragging it back, fusible samples of known melting point might show the
temperature of the depths.
For the experiment, 200 feet of one-inch iron pipe, which was screwed
together in a single long piece, was laid across the north floor of
Halemaumau. Ten assistants were distributed along the pipe twenty feet
apart, and I stood on the rampart with Alec at the edge of the central
portion of the lava lake. This was a high bank ten feet or more above
the streaming liquid lava. The men were instructed to lift the entire
long tube and walk forward with it, so that it would plunge into the
liquid lengthwise, arching down toward the center of the lake as it
came past me. Alec helped guide the pipe over the bank, and the men
came forward with it at a steady walk. The end of the pipe, covered
with a screw cap, was plunged into the liquid lava, traveling toward
the bottom at a good speed. The strong current toward the left dragged
it somewhat, but not enough to prevent its sinking. After two and
a half 20-foot joints of the pipe had plunged into the liquid at a
slope of about fifty degrees, I could feel the pipe encountering the
increasing resistance of a pasty bottom. Continued forward progress of
the pipe caused it to stop and arch up, while the surface lava streamed
past it, and its lower end was definitely stuck in the bottom substance
of the lake.
I then gave the signal to the carriers to try to walk back to the
place where they had started, with a view to pulling the pipe up and
recovering the terminal length. The pipe trailed upward out of the lava
lake like a red hot rope, then stuck and refused to come out. It came
close against the bank where it was frozen solid in the stiff blankets
of pahoehoe crust, which gripped it like hot iron.
The terminal length had been equipped internally with a spiral of
spring steel, containing Seger cones which are used in the porcelain
industry and which bear numbers indicating they melt at graded
temperatures. This first thermometer by meltability was never
recovered. The free lengths of pipe had to be unscrewed close to the
bank, and four twenty-foot lengths were lost. In later tests we learned
to keep the pipe oscillating back and forth so it would not freeze.
The epoch-making significance of this experiment was not understood
until later. Calculation of the angle of slope of the pipe, where it
went down into the liquid and hit on the bottom, showed that vertically
the liquid was about fifty feet deep. With the aid of soldiers from the
Kilauea Military Camp, this experiment was repeated several times; and
each time the lake was found to be the same depth.
This conclusion was later verified by sudden subsidences of the liquid
lava until the cliffs bordering the liquid were fifty feet high. The
eastern grottos turned into cascades, with the liquid pouring down
a well. The liquid lake had become a river pouring over a ledge of
its own bottom, across from the western source wells to the eastern
sinkholes. These latter were fountaining grottos when the lakes were
full, but they exhibited internal rectangular upright sinkholes
when the lake level was down. This was verified repeatedly, and the
phenomena of source wells at the west and cascading sinkholes at the
east were confirmed and photographed. It thus became evident that the
lava lakes were nothing more than convectional lava flows over pasty
solidified substance of their own bottom sediment. Convection means
rising foam, loss of gas, and sinking gas-free heavier liquid.
In other words, the bench magma capped with overflows on the marginal
platforms was a paste, cooled from the top and bottom and sides
and making the saucer of streaming liquid. It was this paste which
constituted the swelling heart of the bench magma. The fountaining of
gas bubbles escaping from solution robbed the lava of heat and caused
it partially to solidify, always at a depth of about fifty feet. Thus
there were necessarily three substances: The deep lava fizzing with
self-heating gases (later proved to be inflammable hydrogen, carbon
monoxide, sulfur, and inert nitrogen and argon), the streaming foam
into which the deep lava expanded, and the semi-solidified refuse of
the foam created at the bottoms and banks of the liquid lava when it
cooled from bright yellow heat (about 1150° Centigrade) to a dark-red
heat (about 900° Centigrade).
The streaming across the bottom from west to east meant that during six
months of rising lava, some 600 feet in the last half of 1916, the lava
column was a cylinder of semicooled lava, maintained by upward pressure
of the deep lava bubbling up in the western crack between the cylinder
and Halemaumau wall. Meanwhile, at all times, the lakes were nothing
more than streams of foam fifty feet deep and skinned over on top,
congealing on their bottoms and shores and cascading down sinkholes in
the eastern wall cracks of the cylinder. A convectional circulation
was what maintained the rising, foaming, heating, and cooling and the
changes in density of the liquid as it lost its gas. Thus the entire
fountaining phenomenon of the lava lakes was due to the self-heating
of what is known as exothermic reaction of gas escaping from solution
in molten basalt. Much of this is actually the burning of hydrogen in
air, creating a convectional circulation wherever the deep lava can
find an outlet.
Ordinarily these outlets are along cracks or rifts in the slope of the
mountain, where they are seen to break out in gassy fountains 500 feet
high, and often to flow along the crack to a cavity where they cascade
downward when less foamy and heavier. A lava flow is always solving a
problem of foaming and liquefying, just as does champagne or beer.
There still remains the unsolved problems of how much of the deep
lava is gas and whether it is mere pressure which holds the gases in
solution, as in soda water. The alternative is for the deeper magma
to be entirely gas, oozing up cracks in the globe, and reacting with
oxygen from the air and solid rock, percolating from the core of the
earth upward, and melting its walls.
In a sense, the entire decade to 1920 was an experiment. The results
of that decade showed that the mountain swells and shrinks in tides
with the passages of the sun and moon, but that Kilauea Mountain and
Mauna Loa Mountain are all parts of what might be called Hawaii Island
Mountain. The island of Hawaii is above an old ocean bottom 18,000
feet deep and is only the end of a ridge 1,700 miles long, which even
at its lowest end, Midway and Ocean Islands, is still 12,000 feet high
above the smooth mud-over-rock ball of the Pacific Ocean bottom. All
the evidence shows the ridge to be a pile of lava flows over a crack,
with a veneer of coral. If, then, the relatively small Kilauea dome
is swelling and shrinking in sympathy with the sun, the long Hawaiian
ridge is doing the same thing to a much greater degree.
Michelson has shown that the solid rock of the globe rises and falls
in a tide about one foot every half day. As I have said, our daily
measurements in 1912 showed that the lava in Halemaumau had a daily
tide and that the larger movements reached maxima in June and December
and minima in the intervening months, which proved it must be a solar
effect. This was very exciting information and suggested a long train
of experiments, which were to be successful in the next decade, based
on the idea that the whole mountain swells as shown by leveling. This
extends out to a radius of twenty miles from Kilauea Crater, and
probably extends all the way to the seashore.
The actual measurement of a lava tide in Halemaumau was done during
July and August 1919. R. H. Finch had just come from Washington to be
my assistant. Oliver Emerson of Honolulu was another assistant, and two
Harvard youths, Sumner Roberts and Charles Thorndike, who had been on
war missions in submarine chasers, sent word through their parents that
they were anxious to do something dangerous around an active volcano. I
jumped at the chance to employ them to help me measure the lava tide.
The north lake in Halemaumau was quite accessible, and we organized
night and day shifts for surveying measurements from a canvas shelter
on the actual bench lava near the lake. For twenty-minute periods, each
observer critically measured a number of monuments on the bench magma
and glowing places of the lake edge. Then a new measurement was started
by leveling the transit. This sequence was kept up night and day for a
lunar month, namely twenty-eight days. One of the monuments was a fixed
Halemaumau benchmark, equipped at night with a lantern and used as a
datum for the fluctuating lake points.
A second tent back from the Halemaumau rim was a camping base. Ford
cars were kept running from the Volcano House for the changing of crew,
Mrs. Jaggar looked out for the food, and I directed repeated surveys of
the position of monuments and of the observation shelter.
Meantime the lava steadily rose during July, and at one time split
open the Kilauea floor making an outflow back of the shelter. The
vertical angles kept track of the movements of both the liquid and the
semisolid lava. The instrument was planted on the lava column itself.
On one occasion, Mrs. Jaggar’s glove fell into a floor crack inside the
shelter and burst into flame.
In all, there were more than 20,000 observations recorded. These were
plotted on coordinate paper, and results were reduced to a smooth
curve by overlapping averages. The actual curve of measurements was
subjected to harmonic analysis at Yale University by Professor E. W.
Brown, mathematician and specialist on motion of the moon and on lunar
tides. The results showed a definite daily tide in both liquid lava
and semisolid lava; of a few inches for the lunar tide, and of larger
amounts for the solar effect. The curve plotted reached its greatest
perfection of daily up-and-down waves during July at periods when the
lava was steady. This became interrupted and ragged when accidents of
drainage out on Kilauea floor pulled the liquid lava down.
[Illustration: _14. River of Alika flow, Mauna Loa, October 6,
1917_]
[Illustration: _15. Lava streaming into a sinkhole in
Halemaumau lava lake, July 7, 1917_]
[Illustration: _16. Sakurajima Volcano, Japan, 1914_]
[Illustration: _17. Fountain in lava lake, March 19, 1921_]
H. O. Wood, seismologist at the Volcano Observatory, was skilled in
compiling the volcano’s historical heights and depths of the nineteenth
century and in plotting our curve of surveys of the liquid lava. He
published a commentary on such plots for 1912–1913 in relation to
solar curves of solstice and equinox, and to the oscillations of the
global axis. He demonstrated a definite correlation between seasonal
fluctuation of sun and moon and the seasonal rise and fall of the lava,
presenting an extensive analysis of the rock tide in the globe and its
application to Hawaiian volcanoes for a century. Perret had made a
similar analysis for earthquakes and volcanoes in Italy.
These curves applied to the seasons, if compared with our lava tide
applied to the hours of the day, left me with the conviction that the
cyclical variations are a fact. They show correspondence between the
swelling and shrinking of the globe and the movements of lava, when
those movements are free and subject to surveying measurements. For few
volcanoes are surveys possible, and our measurements were the first in
the world of any continuity.
Earthquakes, too, were studied. Dr. Arnold Romberg of the University
of Texas--who has become a distinguished inventor in the world of
seismology, magnetism, gravity, and oil prospecting--was Professor
of Physics at the University of Hawaii about 1918 and for several
summers came to the Hawaiian Observatory to assist me in experimental
seismology.
From 1917 to 1920 I took the records of earthquakes and other seismic
movements, as recorded by our Omori instruments, and Romberg remodelled
these instruments. With his knowledge of the fundamental mathematics
of pendulums, for at Harvard he had experimented with sensitive
galvanometers, his facility for making instruments out of nothing but
wire, solder, and old clockworks was wonderful and inspiring.
I spent many months measuring our smoked-paper seismograms of 1913
through 1918, with the assistance of Mrs. Jaggar, to whom I dictated. I
measured types of local earthquakes, of volcanic tremors (some of which
definitely accompany lava fountaining), and tilting of the ground,
publishing the results in 1920. Tilt upswelling is shown in amount and
direction by gradual change of the writing seismograph pens, and this
is correlated with the recorded rise and fall of the lava.
In the course of three years, with Romberg’s valuable advice, we
changed the seismographs to record with little mirrors supported on
silken fibers and with beams of light projected on photographic paper.
And Romberg invented an ingenious improvement with a vane and a bath of
oil, whereby a tilt-free seismograph for earthquakes only would keep
the spacing of its lines uniform. Ground tilt crowds the lines.
We also experimented with a heavy cylinder which hung as a normal
pendulum and which was capable of swinging in any direction, so that
it threw a beam of light vertically upward to a chronograph covered
with bromide paper. The chronograph was capable of being revolved and
stopped, until the mocroseisms and microtremors reached their maximum
of amplitude, for any given period of recording.
The permanent waviness of ground motion, the tremors with periods of
about two-tenths of a second, and the microseisms with periods of
about five seconds showed their maxima of back-and-forth movement
when the chronograph was revolved to a position where the pendulum
swung northeast-southwest. This northeast-southwest tendency was found
to be a characteristic of the seismograph cellar for many seismic
measurements, including local earthquakes.
This was the direction at right angles to the edge of the cliff
on which the Observatory stood. We concluded that this motion was
characteristic of the upright flat slabs, with cracks behind them,
which constitute the face of the crater cliff, and decided that any
motion communicated to these slabs would tend to be a swaying toward
the crater, rather than in the direction of stiffness parallel to the
crater’s edge. Omori has found a similar permanent tendency for Tokyo
city, where the directions are northwest and southeast for maximum
amplitude. This means that any spot on earth oscillates easiest in one
direction.
These first ten years of the Observatory answered many questions and
pointed the way for future experiment and study. It now appears that
liquid lava is a gas froth, that Kilauea and Mauna Loa are all one
system, that hydrogen is the most elemental gas in eruption, that a
gas-free paste is the residue of flowing foam both in pits and lava
flows, that earthquakes and vibrations are a function of this paste
wedging up cracks and sinking back underground, and that the rise and
fall is in tides and cycles, short and long. These things are not
guesses, but measurements.
The earthquake problem at volcanoes is misunderstood in geology. The
superstition that volcanic quakes are small is wrong. “Volcanic” in
volcanology is not limited to volcanoes. Los Angeles, Charleston,
Lisbon, and the deep ocean bottom are all volcanic, are all tremulous;
and all have “lava” underneath. Kilauea and Midway Island are one, Rome
and Etna are one, Iceland and St. Helena are one, Redlands and Mount
Rainier are one, and the paste is underneath. These facts concern the
globe, not a little bundle of wrinkles like the Alps.
We do not know what an earthquake is or what lava is. However, “lava”
falling suddenly and rising slowly with big and few earthquakes
accompanying fall, and little and many earthquakes appearing with
rise, are facts observed at Kilauea. At Tokyo in 1923 the greatest
quake in history centered at lowered lava and lowered sea-bottom next
to Oshima Volcano island. The Messina quake in 1908 made a hissing
noise, and nearby Etna lava was low. There are long cracks in the earth
shell somewhere deep down, and we know little about them except that
volcanoes and faults are in lines. So long as the three-quarters of
the globe under oceans are unexplored by man, with no rock specimens
or even decent maps, and so long as there are no instruments planted
on sea bottoms, we cannot use the term volcanic intelligently. Most
volcanoes of the earth are undiscovered. Kilauea measurements whet
the appetite for a new scientific frontier, the prospecting for ores,
volcanoes, and mountains under the sea. The absence of core drilling
and rock sampling over three-quarters of the earth is a disgrace to the
oil-drilling and quarrying sciences of mankind.
The founding decade of the Hawaiian Observatory produced two effective
expeditions, one to Japan and one to New Zealand.
The Research Association voted to send me to Kagoshima in Kyushu, the
south island of Japan, where the volcano Sakurajima made earthquakes,
explosions, and lava flows in January of 1914. About the same time
Perret was sent to Sakurajima by Friedlaender of Naples, so we met in
Japan.
Sakurajima, or Cherry Island, is a 4,000-foot cone in Kagoshima Sound,
a deep inlet at the southernmost end of Kyushu. The volcano threatened
22,000 persons in villages on Sakurajima Island itself, and 70,000
in Kagoshima. It is a land of orange groves, fisherfolk, Satsuma
porcelain, and maritime commerce, situated at the north end of the
Okinawa-Ryukyu islands, a volcano chain extending north to Nagasaki.
Authorities in Kagoshima knew all about Pelée; and the army, navy,
and governor wasted no time. Professor Omori, who had a seismograph
at the weather station of Kagoshima, went at once to the volcano, and
profiting from the lesson of Pelée, guided the lives of 90,000 persons.
The Sakurajima eruption began on a Saturday and Sunday with hundreds
of earthquakes locally identified as coming from the volcano. Public
and private vessels were called into service to move all the people of
the island over to Kagoshima and beyond. With a general of the army in
command, this was accomplished in two days. On Monday at ten o’clock
the great, picturesque peak, quite like Pelée or Vesuvius, suddenly
ejected vertically and quietly, from a crack in its flank, a column of
“smoke” 30,000 feet high. This was answered by another, similar column
on the opposite side of the mountain; and the two columns joined above
into a colossal arch of cauliflower clouds consisting of sand, dust,
and boulders. The crack in the mountain which gave vent to all this
opened with slight rumble and behaved like two radial ruptures meeting
toward the peak, extending southwest and southeast. The sector of the
mountain between them appeared to have been lifted like a piece of pie
shoved up in the center. But the summit craters played no appreciable
part in the eruption, unless it was a gush of steam on Sunday evening.
The line of craterlets along the cracks and only half way up the
mountain quickly developed lava flows, and these poured down, the one
toward Kagoshima Strait, the other toward the narrow Osumi Strait,
which separated the volcano from the wilder eastern mainland. This
strait was filled up with heavy block lava, or aa, converting the
island into a peninsula. A similar aa lava flow, fifty feet high in
front, swept down to the beach on the Kagoshima side, with boulders as
big as a house tumbling over its andesite front.
Tidal waves made by these two lava flows entering the sea were small
but perceptible. The principal effect was thousands of white steam jets
where the red hot blocks entered the ocean. Culmination of glowing heat
came the second night, Tuesday. The flows continued for months, but the
maximum of seismic effect had happened at six o’clock in the evening of
the first day, Monday.
This was a really big earthquake damaging masonry and causing landslips
from the cliff next to Kagoshima city and killing a number of people.
The flux of refugees from the volcano villages on Monday was a
dramatic event. When the lava outbreak occurred in the forenoon,
the schools sent the children home. On their way, the children gazed
entranced toward the terrific arch of cloud over the mountain, vomiting
trajectories of stones. Shops closed, and the city was quiet while
everybody sized up the crisis. As a schoolboy in English class wrote,
“Monster rocks went horizontally from the down to the up, with smokes
on their behind.”
After the evening earthquake, however, when many buildings had shaken
down, all except public officials were ordered to leave for the back
country. Young men’s clubs organized to receive the refugees along
the roads which led into the interior of Satsuma province, while
temples and schoolhouses were impressed into service to house them.
The migration of more than 50,000 people with packs on their backs and
with handcarts bearing household goods, demonstrated how easily the
Japanese people took to a nomad existence. This hegira came to an end
on Wednesday, when Dr. Omori arrived from Tokyo, sized up the seismic
record and the fiery crisis of Tuesday night, and took the grave
responsibility of announcing that the population of Kagoshima might
safely return. This was done, he was right, and no further damage beset
the city.
Through all of this eruption, so different from Pelée in administrative
control, no one was killed by the volcano, though one or two old people
died of shock. One old lady who refused to leave her home on the island
survived. Village roofs were bent down, crushed, and half buried under
a heavy snowfall of ash, and it was notable that flat-roofed cottages
were crushed, whereas those with steeper roofs were less damaged.
Orange orchards were hopelessly destroyed.
At the west shore of Sakurajima in a place called Hakamagoshi, a fiery
blast rushed down to the sea from the rift. Trees were stripped of
limbs and bark, saplings were bent away from the volcano, and wood
fiber on stumps was shredded by flying rocks. This blast was very short
lived and never reached across to the city. It bore the marks of being
similar to the downblasts of Mount Pelée. The lava flows kept on for a
year and built new shore islands.
I had the remarkable experience of being rowed in a skiff over the
submerged tongue of an eastern flow, trailing a thermometer in the
increasingly boiling water. When the steaming water about us reached
scalding temperature, we had the unpleasant thought that if we should
capsize we would be cooked. We found boiled horses and cattle along the
beaches, and thousands of dead fish. A climb near the eastern flank
vent showed a portion of the moving lava flow pouring down the slope
into a glowing cavern under a shell of its own bouldery texture.
The thousands of dollars of relief which came to Japan from America and
elsewhere were handled with scrupulous honesty, and the inhabitants of
the island were rehabilitated on Tanegashima, another island of the
Ryukyu Archipelago.
Scientific investigations showed by leveling that the mountain had
been lifted a few feet by the internal penetration of the lava, and
reexamination of the benchmarks along roads extending out radially
indicated that the north end of the bay bottom and shore had definitely
sunk, as though underground lava had been withdrawn from that region,
to push up, swell, and overflow the mountain. This effect of subsidence
outside was traced and shown to gradually lessen for a hundred miles
from the place of greatest sinking. Investigation carried out by the
geologist colleagues of Omori culminated in a monumental publication
which demonstrates the solidarity of the Japanese methods of science.
And both Omori and Professor Koto published books on Sakurajima in
English, with maps, photographs, curves, and seismograms.
Omori, in 1910, had anticipated movement of the earth about a volcanic
center as swelling up one place and sinking down in another while
eruption was going on. At that time, he described Usu Volcano at
the opposite end of Japan, where leveling instruments showed graded
changes in height made by the Usu eruption. A remarkable physiographic
character of Usu Mountain, and of the adjacent basin of Lake Toya,
is that basin and dome appear complementary, just as Kagoshima Bay
was compensated by Sakurajima. This same pairing of lake with volcano
has been noted in other parts of Japan, as though tumefaction by
lava penetration and lava eruption had robbed the underpinning of an
adjacent piece of ground, which lowered and became a lake by filling up
with groundwater.
From Sakurajima I went to Bandaisan, or Kobandai, a famous volcano in
central Japan northwest of Tokyo and on the shore of a beautiful lake.
It looks like an ordinary rocky peak, but its fame was made by a steam
explosion from its flank which blew out the side of the mountain and
left avast sulfurous quarry with numerous solfataras and hot springs.
Bandai was known by geologists to be one of a chain of volcanoes, but
prior to 1885 its activity was in question. One morning the sky was
darkened by the overwhelming explosion, and vast volumes of rock from
the outbreak poured down as a landslide and completely dammed a river
system. It left extraordinary little heaps in the new dammed up lake.
These appeared to be individual blocks of rock against which heaps of
debris were piled so as to leave pyramidal humps scattered over the
surface of the impounded water near the volcano. An excellent report in
English on this eruption was published at the time, and the eruption
became the type of what geologists call a phreatic explosion, meaning
pure steam. There was doubt as to whether any fragments of new lava
were thrown up.
I took with me to Bandaisan a photographer-guide. We camped in a
mountain inn with thatched roof, visited a hot spring resort, and hiked
to the crater where we measured temperatures and took photographs. It
was a vast flat-floored shelf, dug out of the side of the mountain,
with steam jets and puddles of boiling water at the back. Looking out
at the new water-filled valley with its many islands at the base of
the slope below the crater, we could see shoreline levels higher than
the present beach, where the damming had produced the highest stand of
the water. The eruption and landslide overwhelmed villages and killed
many people, though it lasted only a few days. It was on the side
of the mountain remote from the older lake. In clambering over the
broken debris, which looked more like glacial deposits than volcanic
agglomerate, I picked up some pieces of vesicular basalt that were
definitely lava. Wada, a Japanese geologist, had found the same thing,
and we both concluded that these were an internal live basalt blown to
fragments in the Bandaisan eruption, but that most of the material was
from the shattered old mountain.
My interpretation of Bandaisan is that it is an old volcano in the
line of Asama and other volcanoes of central Japan, and that the line
is a deep crack always full of lava in the depths, which is selective
of outlet, depending upon what part of the crack opens as the path of
least resistance. Eruption may be occasioned by lava wedging upward at
one volcano, or by lava sinking downward at another volcano, according
to the way the medial rift of continental Honshu is warped and stressed
by the earthquake forces. One part of a volcano chain is always
sinking, with lava withdrawn. Another part is always swelling up, with
lava penetrating the cracks under active crater pits, like that of
Asama.
Asama is the Vesuvius of central Japan near the village of Karuizawa,
famous as the resort of American missionaries. Bandaisan is one of a
line of volcanic peaks north of Asama, all of which have hot springs
and solfataras. The explosion of Bandaisan, where the big natural lake
represents the groundwater level of abundant rainfall, occurred when
the underground lava column suddenly sank rapidly by the gaping open
of the deep rift. The water poured into red hot cavities, while the
lava was rising and erupting by frothing up in the depths of one of
the other volcanoes. The results of Bandai’s explosion were first,
earthquake collapse, which was assisted by vast outjets of boiling
steam from groundwater, and then the blowing out of the mountainside.
Of special interest is the spacing, twenty to forty miles, between
volcanoes along such a system as Asama-Bandai. The underlying cracks
must be in echelon arrangement, and the spacing is a function of the
thickness of the upper earth crust and its capacity through the ages of
producing spaced-out widenings or bends in the crack, above whatever
shell confines the lava. The same spacing of the new and old volcanoes
is true in the Caribbees and in the Costa Rica-Mexico line. There
an old peak might make a Bandaisan by unforeseen breakage and steam
development.
This applies also to the Ryukyu-Sakurajima line. I visited Kaimon at
the extreme south end of Kyushu, a steep dome blocked on top by a
lava plug. South of here to Suwanose Island, an active volcano, the
spacing of islands is similar to the northward spacing of Sakurajima,
Kirishima, and Asosan, following the same law of selected vents
and offset cracks. Kirishima thirty miles north of Sakurajima is a
treacherous and dangerous volcano that made a bad explosion just prior
to the Sakurajima eruption. I saw on the rim of its summit cavity a
breadcrust bomb, a triangular block of rock eight feet long, with its
surface beautifully tessellated with gaping cracks. This breadcrust
fracture indicates that the fragment of glowing andesite was thrown
up while pasty, then congealed on its surface to smooth glass and
continued to swell evenly with internal gas, so as to rupture the
glassy surface as expanding dough.
At Aso Volcano farther north I entered a natural gateway into a
cauldron nine miles across, surrounded by a wall, and with a hilly
country inside, from which a river escaped through the gateway. The
summit peak in this landscape proved to contain an active pit on top.
The pit was steaming and the source of the steam was boiling puddles
of mud at the bottom. This was the “Halemaumau” of Asosan, which has
had a record of many eruptions near the city of Kumamoto. The chain
of Kyushu volcanoes ends, after the usual spacing, with a volcano at
Nagasaki.
From Shimonoseki Strait, going northeastward, new belts of volcanic
fissures have built the mountains of central Japan, cut across
northwest of Tokyo by what Naumann called the fossa magna or big
trench. This is famous in the history of Japanese geology, for which
this German geologist laid the foundations. The fossa magna extends
northwest and southeast, through Fujiyama and Oshima Volcanoes to the
Ogasawara Islands and the Bonin Islands, scene of volcanoes making and
disappearing, from craters under the ocean.
Omori had discovered historical similarities between the eruptions of
this chain and those of the Ryukyu chain. This is significant, because
as we go from the small spacing of the individual volcanoes, we come to
some deeper and larger fracturing of the whole crust of the earth that
determines a spacing of hundreds of miles between such larger arcs of
rupture as those of Kyushu and the Bonin Islands. As all are volcanic
and have been so since the birth of the globe, it is unthinkable to me
that they are anything but deep fractures which go down to the earth’s
core. The surface geology of marine strata is a mere veneer compared
with the deep and ancient igneous rocks.
I went to New Zealand in 1920, taking with me in manuscript form
the Hawaiian Observatory results of the past decade. Notable among
geologists there was Dr. Allan Thomson, director of the Dominion Museum
in Wellington. Dr. Thomson and his distinguished father, the Honorable
William Thomson, guided Mrs. Jaggar and me all the way from Auckland to
Dunedin. It was my task to give lectures on volcano research, to show
lantern slides of Mount Pelée and Kilauea, to tell about seismographs
and cycles, and to urge upon New Zealand science the importance
of establishing a volcano observatory system in the Taupo Belt of
volcanoes.
Here, in 1886, had occurred the terrific eruption of Tarawera. Here
are spaced out volcanoes extending north into the islands of Tonga.
Here, possibly, along the Cook Channel between the North and the South
Islands, is a transition from volcanoes to earthquakes, and quite
possibly another fossa magna worthy of comparison with Japan. Off to
the east lies the profound linear Tonga Deep, compensating the New
Zealand volcanic uplift. This is analogous to the Tuscarora Deep east
of Japan.
We were fortunate to procure accommodations in Rotorua, the boiling
geyser district, at the time of the visit of the Prince of Wales, later
King Edward VIII, and to see the hakas, or dances, of an encampment of
5,000 Maoris, gathered to honor British royalty.
I was interested in the relics of liquid basalt collected on the lip
of the great rift through Tarawera Mountain. The rupture extends the
length of Rotomahana Lake, which sank away as a groundwater phenomenon
in 1886. This, like Bandaisan, was one of the great steamblast
eruptions of history. It was right on the line of volcano spacing
extending from White Island in the Bay of Plenty, to Ngauruhoe and
Ruapehu Volcanoes, beyond Lake Taupo at the south. Here was a land
of echelons of deep cracks, building up along scores of miles from
submarine eruptions such as Falcon Island in the Tonga group. Farther
south is the dangerous looking White Island close to the New Zealand
shoreline, resembling Bogoslof, and so on to the lava volcanoes at the
south. Big earthquakes have been characteristic, along with uplift, of
both shorelines of Cook Strait.
This kind of gradation is certainly like the transitions from
submarine eruption to continental uplift, crowned with volcanoes, so
characteristic of Japan, the Aleutians, California, and Italy. It is
impossible to think of it, when we consider water depths of 4,000
fathoms, and a step upward to such altitudes as the New Zealand alps,
all linear for a distance of several hundred miles, except in terms of
the faulted deep earth crust. And seismologists tell us that that crust
is 1,800 miles deep.
The associations made on this trip were destined to have far-reaching
effect in meetings with New Zealand scientists at later dates. I
met Professor Bartrum of Auckland; the officials of the New Zealand
Geological Survey; Dr. Ernest Marsden, distinguished physicist who
had worked with Rutherford in England; and Dr. C. A. Cotton, physical
geographer and author. Cotton showed us the elevated shorelines
of Wellington associated with the big earthquakes of 1851. Other
personages were Professor Speight, geologist of Christchurch College,
and in Dunedin, Professor R. L. Jack, physicist of Otago University
and our host. Dr. C. E. Adams, government astronomer of Wellington,
we were to meet again on Tin Can Island in 1930, during the United
States Eclipse Expedition. Dr. J. MacMillan-Brown, chancellor of
the University of New Zealand, and his daughter entertained us in
Christchurch; and he later visited us several times in Hawaii in the
course of his extensive travels.
I was glad to stimulate volcanology in New Zealand and pleased when
there eventually appeared the splendid work of Dr. L. I. Grange, on
the “Rotorua District,” with a project for geophysical surveys made
imperative by the Napier earthquake disaster.
Before this chapter is closed, some personalities of the first decade
of the Observatory should be mentioned. Foremost was L. A. Thurston,
founder of the Volcano Research Association and its president for many
years. It was his interest and enthusiasm coupled with that of the
other members of the Association that made the Observatory possible.
Prominent among those members was L. W. de Vis-Norton, for many years
secretary of the Association and a devoted apostle of volcanology.
Mrs. Isabel Jaggar, from 1917, was my helper not only as wife and
amanuensis, but as general assistant at the Observatory. She could
operate instruments, take notes at the pit, keep the record books, and
act as buffer against an overinquisitive public.
There was Demosthenes Lycurgus, genial Greek host of the Volcano House,
who did all in his power to help us, by grants of lands, raising money,
and personally promoting science with all the vigor of his wonderful
personality. He went home to Greece to be married, and alas, died
during his honeymoon. Later came my good friend George Lycurgus, who
still operates the Volcano House.
Colleagues of the founding decade included H. O. Wood, who came from
Berkeley in 1912, acted as seismologist and geological assistant, and
established a seismological bulletin. He left to enter the army in
1917. In years to come Wood established in Pasadena under the Carnegie
Institution one of the great seismographic laboratories of the world,
and his name became coupled with a California Institute of Technology
physicist to name the Wood-Anderson seismograph. Later came R. H. Finch
who had worked with Dr. Humphreys of the Weather Bureau in Washington
and had been a flight meteorologist in Ireland during the first World
War. He was assigned by Marvin to me as assistant in 1919, when the
Congress took over our work for the U.S. Weather Bureau.
Finally, I should like to name the numerous workers of the U.S.
Geological Survey in topography and geology, notably Birdseye,
Burkland, Stearns, Wilson, Clark, Meinzer, and Macdonald. These men
brought to reality my Geological Survey estimate of 1899, when I
recommended to Walcott a survey of the Hawaiian Islands.
The Hawaii geologic survey included investigations of water, highways,
and minerals, and was to map lavas, volcanic processes, and island
growth. The annual cost of the work had been estimated at $22,000,
including $6,300 for salaries in geology and $10,000 for the total
cost of topography study, or $90,000 for five years. The project was
begun in 1909 in cooperation with the Territory of Hawaii. In 1951 the
mapping was completed and the cost had been many times the original
estimate.
Among visitors who contributed to the Observatory work were Sidney
Powers, a voluntary observer who had been one of my students in Boston.
He explored and published on many volcanoes around the world and
followed me in Sakurajima and the Aleutian Islands. He later became an
outstanding petroleum geologist of the Amerada Company in Tulsa. Arthur
Hannon, an architect from Cleveland, acted as a volunteer mapper, and
for months aided with sketches of the changes in Halemaumau. William
Twigg-Smith, an artist from New Zealand, joined us in the lava-sounding
experiment and made numerous sketches and paintings. He later became
the illustrator and photographer for the Hawaiian Sugar Planters’
Association. Dr. A. L. Day of the Geophysical Laboratory visited us
repeatedly, in association with gas chemist E. S. Shepherd. He wrote
important monographs, along with E. H. Allen the chemist for the
Carnegie Institution, on the Yellowstone and Lassen National Parks, and
on Geyserville. Allen came to the Observatory for critical analysis of
the steam of Sulphur Bank.
Among other visitors were geologists, geodesists, and biologists of the
Pacific Science Congress, held in the spring of 1920. These included
H. E. Gregory, Griffith Taylor, Frederick Wood-Jones, William Bowie,
T. W. Vaughan, E. O. Hovey, E. C. Andrews, F. Omori, H. S. Washington,
and Dr. Chilton of Christchurch, who had been one of our inspirers in
the New Zealand trip. This Honolulu world congress assigned one meeting
to Kilauea Volcano, which enabled me to summarize results before a
cosmopolitan group of scientists.
The Washington executives who at this time promoted the Observatory
were Secretary of Agriculture David F. Houston, Director George Otis
Smith of Geological Survey, Chief Charles Marvin of the Weather Bureau,
and Charles D. Walcott, Secretary of the Smithsonian. Later came W. C.
Mendenhall, firm friend of the Observatory, and Director of the Survey.
It was my good fortune that between 1914 and 1919 Mauna Loa and
Kilauea were building up lava toward a fiery crisis, and that the
sugar business of Hawaii boomed at the same time. When the 1920
science congress convened there was much fresh lava to be seen, and
our Research Association was so prosperous that M. I. T. in Boston
kept up its financial interest. The _American Journal of Science_
under Edward Dana of Yale published our results. This was fitting, as
Dana’s father, J. D. Dana, had published much about Hawaiian volcanoes.
Consequently the end of the foundation decade made easier the financing
of the next five years. Just at this time the Geological Survey spurted
ahead, the National Park was opened, the Army built a recreation camp
and a trail up Mauna Loa, the Inter-island Steamship Company took over
the Volcano House, and a Promotion Committee was bringing many tourists.
[Illustration: _Fluctuations of Halemaumau lava from 1790 to
1952, the verticals indicating maximum lowering preceding repose
periods; minor fluctuations not shown._]