January 31, 1917 Earthquake: Glan,glan Padidu,tuyan, S Mindanao, Philippines

Reference #414:

1917, January 31, 11:38 [local time, 3:39:55 UTC, 6 N., 125 E.; magnitude 6.4]. There was an earthquake with source to the south of Mindanao Island, near Sarangani Bay. It was felt all over Mindanao Island and in the eastern part of the Sulu archipelago. The tremors were strongest, 7-8 degrees (VIII-IX Rossi-Forel) to the east and southeast of Sarangani Bay, in particular at Glan. According to a report of the police station at Glan, the tremors lasted about a minute. Eighteen buildings collapsed, including the school, a new warehouse and so on. The public pier was completely put out of commission and required major repairs. All the buildings of the police station at Glan were destroyed, except for one new annex; two people were injured by falling beams. Seven people died under a large landslide at Tuyan (a suburb of Glan). A mass of cracks up to 1/2 m wide appeared in the ground. At many places, water and mud spurted up several meters. Recurrent shocks were felt all day and all night, and seven strong earthquakes and many weak ones were registered in Glan in February. A tidal wave 1-1 1/2 m high high appeared at Glan several minutes after the earthquake of January 31.

Reference #1187:

1917, January 31, 12:02 p.m. [local time]. Intensity IX, 5.6 N, 124.8 E. S Mindanao: Sarangani Bay - In the town of

Glan and its nearest suburbs on the east and southeast shores of the bay, wooden structures of the constabulary and many native houses were destroyed; cracks and slides

were also produced in the ground; one landslide killed seven persons in a suburb. The destroyed wooden structures suppose to have been of the temporary type used in such

outlying posts, while the native houses are commonly a hut of bamboo and palm leaves, raised from one to three metres above the ground on bamboo or wooden poles very little

driven into the soil. Such structures are not earthquake-proof especially when the rocking lasts for nearly a minute, as happened in this instance. To these unfavourable conditions of the structures must be added the soft and loose character of the soil, consisting of volcanic

tuff, sand and ashes, lightly covered in places by alluvial

material from the Glan River... The damage to all government buildings, property and supplies was estimated at $4,510.69.

Reference #1058:

1917, January 31. Intensity IX. S. Mindanao and Cotabato. Very destructive, tidal wave: 7 victims.