Download California`s Natural Hazards

California’s Natural
Hazards
Chapter 13A, Section 3
California’s Earthquake Hazards







Natural Hazard – an event that results from Earth processes
and that can cause damage and endanger human life
Natural hazards that result from California’s earthquakes
include tsunamis, seismic shaking, liquefaction, and landslides
Scientists have evidence that in the past 200 years, more than a
dozen locally generated tsunamis have struck the CA coastline
Seismic Shaking – measure of how much ground movement
occurs during a quake
The amount of shaking depends on the rock and soil location
of an area
Modified Mercalli Scale – describes the effects of seismic
shaking
Earthquakes in CA can also cause liquefaction and landslides,
collapsing and damaging homes
West Coast Tsunami Warning System
Earthquake Hazards
Earthquake Hazards
California’s Volcanic Hazards







Natural Hazards from volcanic eruptions in California include
volcanic ash, lava flows, and volcanic gases
The Cascade Range stretches from Washington into northern
CA
Cascade volcanoes in CA include: Black Butte, Mount Shasta,
Medicine Lake Volcano, and Lassen Peak
The two volcanoes that are classified as active are Mount
Shasta (late 1700s) and Lassen Peak (early 1900s)
Volcanic Field – an area covered by volcanic rocks
The Long Valley Caldera is the focus of a large volcanic field
on the eastern side of the Sierra Nevada (some rocks are only
a few hundred years old!)
Carbon dioxide escaping from the ground beneath Mammoth
Mountain is killing trees in the area
Long Valley Caldera
California’s Storm Hazards





Two main storm-related hazards in California are
mudflows and flooding
The dry conditions in southern CA make it very
susceptible to mudflows and flooding, especially when
precipitation is greater than normal
A mudflow is a mass of very wet soil, and sometimes
rock, that flows quickly downhill
At top speed, a mudflow can move nearly 60 km/hour,
destroying everything in its path
Flash floods occur in mountains and deserts; they can
be deadly because the floodwaters rise rapidly and
move quickly
Mudflows and Flooding
Assignment



Read Chapter 13A, Section 3 (pg. CA 20-CA 26)
Do Section 13A.3 Assessment #1-6 (pg. CA 26)
Study for Chapter 13A Quiz!