June 7, 1892 Tsunami: Awu Volcano, Sangihe Island, Indonesia

Ref #414:

June 7, 1892. There was a powerful eruption of the Awu Volcano on Sangihe Island, which generated, so far as can be judged from the fragmentary data, joint gravitational oscillations of the atmosphere and the hydrosphere of the same type as the waves from the Krakatau explosion and corresponding oscillations in level [seiche type?] in the internal seas in Indonesia.

The eruption began at 18:10 without any preliminary phenomena. A huge column of smoke rose over the volcano. Lightning flashed. It rained with a mixture of ashes. This soon became a real ash and rock fall.

The explosion of the volcano was not accompanied by noticeable tremors of the island. The eruption reached extraordinary power at about 21:00. After this, the fall of pumice stopped, and the ashfall also diminished by midnight. Soon after the eruption, boiling mud flows saturated with hydrogen sulfide, presumably formed as a result of the emptying of the crater lake, rushed along the crevices which furrowed the slopes of the volcano. As a result of the eruption, 1,532 people died on the island, or 2% of its population, since many huts collapsed under the weight of ejecta, while others were washed away by the streams. The northern part of the island suffered considerably more than the southern. Gardens, kitchen-gardens, and coconut plantations were buried.

The loud noises of the explosions of the volcano were heard on Ternate Island from 18:00 to 22:00 and then at night until 2:00. At Manado, several explosions were heard for half an hour after 18:30, and flames flickered on the horizon to the north. At Tolitoli and Donggala, and also at many parts in the southern and eastern regions of Sulawesi Is. and on Kabia Island, including Makassar and Maros and on Timor Island, at 19:30 and later, very faint muffled booms were heard, like distant artillery fire. Similar sounds were heard at 20:30 at Ambon and at night on Flores Is., at Larantuka.

The sound wave was followed by a gravitation wave, which caused perceptible tremors at a number of places. Prolonged faint trembling of the ground was felt in the evening on Ternate Is. At Makassar at 1:57, tremors 3-4 degrees in strength were registered. Similar oscillations were registered at Maros and in general in the southern and eastern regions of Sulawesi Is. and on Kabia Is. At Bima, on Sumbawa Is., very strong horizontal oscillations were felt from 2:05 to 2:15, and very weak [ground] waves were felt at 5:10 and at 8:10. Several huts collapsed on Flores Is. at Reo. At Maumere, horizontal oscillations lasting 2 minutes were felt at 2:30; one hut collapsed. At Ende, strong oscillations were felt at 1:00. At Larantuka, horizontal tremors lasting 2 minutes were felt at 2:30; one residence collapsed.

At Surabaja at 1:34, the pendulum of the astronomical clock stopped.

At Djakarta (Batavia), the magnetograph registered an earthquake at 1:17 and then at 1:21 and 6:00.

Oscillations in sea level were noticed at Bonthain, Bulukumba and Salajar; the only consequence was minor damage to one boat in the Tanga River at Bonthain.

At Bima, oscillations in level were noticeable at 3:00. The water rose high at the entrance to the bay; this was accompanied by a loud noise, which was even heard in the home of the local superintendent, a 2-hour walk away. This rustling lasted 20 minutes, after which the water began to rise very quickly. The highest rise of water was observed at 5:00, when there should have been an ebb.

A weak tsunami was observed at 7:00 in Ambon Bay. In a few minutes, the water level oscillated from the highest to the lowest level, with a range of more than 1.5 m.

Note: Ref#4659 lists date as 1892 June 02.