Earthquakes

 

Quake Lake (also known as Earthquake Lake) is a lake in Southwestern Montana, United States. It was created after a massive earthquake struck on 17 August 1959, killing 28 people. © Raymond Hitchcock / Flickr

In tectonically active regions of the world, large earthquakes disturb forests over extensive areas and as such are important determinants of forest structure and function. The intensity of damage to forests varies strongly with distance from the earthquake’s epicentre.

Earthquakes can trigger landslides while those occurring underwater can produce tsunamis. It is generally considered that the primary cause of tree mortality during earthquakes is as a result of the landslides they create; forests are often completely removed or submerged by such landslides. However much of the immediate impact of an earthquake is widespread, low-intensity tree mortality and injury.

Damage is caused by the shaking or shearing of tree roots, the uplift of the ground surface, or changes in the water table. The movement of soil or boulders downslope can also damage trees. Damaged trees may survive but they will exhibit signs of the disturbance such as fractures in the wood, growth suppression or the production of reaction wood. The diversity of earthquake impacts is a major source of heterogeneity in forest structure and regeneration.

 

last updated:  Friday, June 28, 2013