Hazards Produced By Earthquakes

Question 1

Ground shaking/displacement

Answer 1

Severity depends on magnitude, distance from epicentre and local geology

Areas with surface layers that are unconsolidated and have high water content =extreme shaking

EXAMPLE: Mexico city in 1985 or Kobe, Japan in 1995

Buildings can withstand verticle shaking better than horizontal ones which cause buildings to sway

Question 2

Liquefaction and example

Answer 2

If an earthquake targets an area with surface materials of fine grained sands with a high water content, vibrations can cause the ground to behave like a liquid

Materials lose their strength and structures sink as foundations give way

EXAMPLE: kobe earthquake because it was built on reclaimed land in the Osaka Bay

Question 3

Landslides and avalanches

Answer 3

Ground shaking and liquefaction can cause slope failure

Himalaya-Karakoram range is notouriously unstable which is increased by deforestation and monsoon rains so slight trmors can cause landslides

EXAMPLE: Nepalese earthquake 2015

Question 4

Tsunamis

Answer 4

Underwater earthquakes can cause the seabed to rise which displaces water causing tsunamis which can exceed 25 m in height

Question 5

Underwater landslides and example

Answer 5

Caused by earthquakes and can also displace water and cause tsunamis

EXAMPLE: In 1998 Papa New Guinea- 2200 villagers were killed by a tsunami generated by an underwater landslide