Disaster Hotspot- California

BACKGROUND INFORMATION:

-One of the world's most wealthiest places

-It's economy is the world's 6th largest

-USA's most Hazardous state

Two reasons for this:

1) Plate Tectonics

2) Climatic Patterns (El Nino, La Nina)

1) The San Andreas Fault runs the length of California- it is a conservative plate bounday

2) The Pacific Plate moves more quickly than the North American Plate. Both move NW

3) Earthquakes occur when pressure between the plates builds up and then is suddenly released

4) Has 2 or 3 earthquakes each year that are powerful enough to damage structures (5.5+)

EXAMPLE: Loma Prieta 1989

-Magnitude + location: 7.1 at Epicentre in the Santa Cruz Mountains

-5.2 earthquake struck the region 37 minutes after main earthquake

-63 died

-1018 homes destroyed

-Huge economic damage of US$6 Billion

1) Can be caused by Anticyclones- high air pressure with sinking dry air and no rain

2) Can also be caused by La Nina- The surface water in the Eastern Pacific is cooler- less evaporation- less precipitation

3) Another cause is increased wind blown from the West from the desert areas e.g. Arizona

Effects:

-Wildfires

Example: Southern California 2007:

-Killed 22 people and destroyed 1300 homes

1) More than 70% live within 50 km of a fault line

2) There is a lot of building on unstable land- this can lead to soil liquefaction during earthquakes, which damages building and increases the risk of landslides. Major problem in the Loma Prieta 1989 Earthquake

3) Many building along the coast that are vulnerable to Tsunamis

4) California is a very wealthy state but there are poor areas within it

5) 20% live below the poverty line. These people have the lowest capacity to cope

6) Has a massive economy so there is likely to be huge economic damage