December 11, 2018 Tsunami: Bureya, Far Eastern Russia

Reference #12996:

The landslide caused a tsunami wave, which spread along the reservoir for 11 km in in both directions along the Bureya River valley and for 3.2 km along the valley of the Sr. Sandar river located opposite the landslide. The maximum height of the wave splash reached 90 m in the narrow part of the valley in the middle reaches of the river Sr. Sandar. The wave completely destroyed the forest on an area of 300 hectares and washed away slope deposits at an area of about 100 hectares. On the slopes, numerous erosion furrows were formed up to 20 m long and up to 1.2 m deep. Now on a wall of failure collapses and small landslides became more active.

Reference #12481:

Below is a brief summary of the results of the field survey of the affected area that was carried out from June 16 to 21, 2019. Geologists, hydrologists and tsunami experts from several research institutions of RAS participated in this survey.

The most important results of the field survey were the fine (up to 1-m) resolution DEM of the landslide and the nearby area and the instrumental measurements of run-ups and inundation distances of the resulted water wave. In total, about 50 measurements were made. The maximum run-up reached at the bank of the Sredniy Sandar river (actually, a creek flowing from north into the Bureya river just near the landslide), turned out to be equal to 90 meters. With this value, the December 11, 2018 Bureya tsunami shares with the June 17, 2017 Greenland tsunami the seventh-eighth places in the global list of the largest tsunamis of the landslide origin, having instrumental measurements of this parameter.

The maximum penetration of the water wave along the valley of the Srendiy Sandar river was 3.75 km, the water stopped at an altitude of 78 m above the undisturbed water level at the time of the event. There the wave left a pile of tree trunks up to 2 meter in heght. The maximum run-up reached by the wave on the gentle slope of ​​the right (northern) bank, faced directly to the landslide, was up to 55-60 meters, with an inundation distance up to 650 meters from the water edge. All the trees and soil cover in this area were completely removed. The height of the mound of broken trees left at the inundation limit in this area reaches 5 meters.

The run-ups on the left (southern) slopes, at a distance of up to one kilometer from the landslide, were within 35-45 meters in upstream direction, and within of 25-35 meters in the downstream direction.

In the field survey, it was found that the actual run-ups were by 5-10 (sometimes up to 15) meters higher the trim line of complete destruction of the forest and soil cover, visible in air photos and satellite images of the affected area.

Reference #12867:

In the deep (down to 70 m) reservoir, the landslide generated a destructive tsunami-like wave whose impact on the shore was emphasized by a thick (up to 20 cm) ice cover. The maximum run-up that was reached at the point 2.8 km away from the landslide on the right bank of the Sredniy Sandar river which flows into the reservoir just against the landslide, turned out to be equal to 90 m.

The total surface area of the landslide body is 270 thousand m2. The landslide’s total volume calculated based on the results of geodetic measurements, is 24.5 million m3, with about 4.5 million m3 of rocks in its surface part.