My experiments with volcanoes

by Thomas Augustus Jaggar

Yokohama, which I had known well in 1909 and 1914, was a tumble of ruins; and the long Bund with its splendid waterfront structures, including the Grand Hotel, was a heap of rubble. My classmate Purington, a mining geologist who had been staying at the Grand with his family escaped with one child and went back to rescue his wife. A second shock brought down more masonry and crushed him.

We were given a tent and allowed to mess with the marines, and next day we crowded into a train for Tokyo. It was packed to the doors and had people seated on the roof. We were warned by Americans to dress as roughly as possible, as the populace was on edge, and foreigners must not appear to be tourists. By great good luck we got into the Imperial Hotel which had withstood the shake and fire, though it was considerably damaged.

We visited the Honjo district of the river bottom, where the damage was at maximum, and we saw the remains of a pile of corpses, clothes, and household goods in one small yard where 30,000 people had been incinerated. Fire had closed in from all sides, and the shrieking mob of men, women, and children piled up on top of each other, amid handcarts and clothing bundles—kindling which added fuel to the horror.

The mayor of Tokyo sent us in a small steamer to the island of Oshima, on which is the volcano Mihara, close to the earthquake center. We climbed up and looked down into a glowing pit which was making no lava outflow at the time, though Mihara is famous for basalt flows.

Water soundings showed 900 feet of subsidence in Sagami Bay opposite Oshima, and there were changed depths elsewhere, some of them shallowing by underwater land slips. We went to the Boshu Peninsula east of Tokyo, where the beach had been rising for many years, and where the earthquake rising left wharves high and dry. The principal effect of the earthquake, occurring at noon just when all charcoal braziers were lighted for luncheon in the flimsy Japanese houses of wood and paper, was to set fires in an area of hundreds of square miles and a score of towns. Water reservoirs were destroyed, there was no adequate fire department to care for a conflagration, and a high wind was blowing in the bright sunshine. A characteristic of Japanese cities was the absence of open parkways for refugees, hence the crushing, burning, drowning, suffocation, and annihilation of hundreds of thousands of people and the destruction of factories, railroad trains, water supplies, power plants, and every essential utility in a great metropolitan area with a population of many millions. The horizontal movement of the ground in the shock was about eight inches, and aftershocks kept on for many months.

We explored Yokohama, clambering up to the Bluff where everything was wrecked and where land slips had tumbled down the precipice. We visited what remained of a beautiful English type villa with a slate roof, which had been occupied by two missionary ladies and their numerous parrots. These people were encamped, along with their parrots, in a shack built by their yardman, for the residence had tumbled down like a house of cards. One woman had been imprisoned between her bed and the wall, and was quite uninjured when the gardener dug her out through cracks of the roof.

Scientifically, what happened to the ground in this earthquake was not explained by any single fault. Whatever happened to the bottom of Sagami Bay was not communicated across the beach to the coast as any great rift. Small faults were identified in a number of places, the shoreline in one place lifted a few feet and lowered in another; but no such movement as the big subsidence of the bottom of the bay crossed the contact of sea and land. It appeared as though the margin of the bay itself outlined an area of sudden slumping, somehow related to Mihara Volcano on Oshima; but the shoreline of that island was not seriously affected. The great mountains of the foothills of Fujiyama, and the Hakone district, were shaken to a hash of broken railway tunnels and land slips, but the topography was not altered.

A resurvey of trig stations west of Tokyo revealed movements that indicated the country had been spirally twisted. However, it has always seemed a mystery to me that all the motion on land was so small, when change on the bottom of the bay was so great.

There was a local tidal wave at the bay shore of Kamakura, but no great tidal wave from the deep ocean came to Tokyo. Some volcanic effort of deep lava had wedged open and jolted the sea bottom, but how it acted is entirely obscure. It was quite different from the San Francisco quake, with its side slip of twenty-one feet and a crack 400 miles long.

When we returned to Japan in 1926 with the Pacific Science Congress, the restoration of Tokyo was practically complete and a magnificent greater city had been built with wide and large parkways. The government was lavish in its entertainment of the scientists attending the congress. Dr. Lacroix and I were sent to Osaka to lecture, and to show lantern slides of Mount Pelée; and expeditions all over Japan were arranged for the visitors. I had an opportunity to see for the first time the large basaltic lava fields of the lake district at the base of Fujiyama, and I was astonished at the similarity of the basaltic pahoehoe to our Hawaiian outflows and the freshness of the lavas and the lava caverns. I had never thought of Fujiyama as a “lava flow” volcano.