California Flashcards
Population
40m
What economy
If its own country, top ten
What megacities
Los Angeles, San Diego, San Francisco
What % LA residents live below poverty line
20%
Population distribution
70% within 50km of a fault line, most on coast
What fault
San Andreas
Geology
Built on soft basin sediments so liquefaction and rapid soil shaking
Earthquakes
1989 Loma Prieta: SF, Mw 6.9, due to a slip, liquefaction collapsed double decker highway, 63 dead. 1994 Northridge: LA, Mw 6.7, due to a dip slip, 60 dead, most damaging since start of century
Earthquake management
6 steps to stay safe, ground motion sensors, Trans American pyramid resistant, SF city hall retrofitted with base isolation, insurance from California Earthquake Authority
Volcanoes
None since 1915 Lassen Peak, in S part of cascade range with N more active e.g. Washington Mt St Helens
Volcano management
Monitoring
Tsunamis
1964 earthquake off Alaskan coast caused one that killed 12 people in Crescent City
River flooding
El Nino makes more susceptible, LA and San Gabriel rivers at risk as deforested hillsides
River flooding management
Heavily channelised, still at risk
Coastal flooding
Erosion risk along coast near Malibu and Santa Monica, likely to worsen in future
Droughts
An issue in Mediterranean climate as anticyclones (long lasting high pressure periods), from 2011-17 6% food price increase, 129m trees died, La Nina cycle
Droughts worsened by
La Nina, winds over deserts e.g. Arizona, rapid LA population growth and lack of water
Drought management
1300 reservoirs fill in Winter
Wildfires
Main effect of drought, worsened in Santa Ana wind period and as people move from LA and SF to the hills
Wildfire management
California Fire Plan
Landslides
High risk as on steep slopes and coastal land e.g. Malibu, Santa Monica, worse in Winter storms and El Nino
Advection fog
Cool air from cold offshore current meets warm air, SF
Photochemical smog
Climate and car pollution, better now in LA as low emission zones etc.
