Examine the reasons why California is described as a disaster hotspot
A disaster hotspot is an area that is extremely at risk due to the fact that it is prone to
multiple types of hazards and that it overlaps
Fig. 1.Dregg’s Disaster Model with a vulnerable population shown by Dregg’s
Model (Fig.1) California is considered to be a
disaster hotspot, which has a very high disaster
risk due to its high vulnerability as a result of its
highly densely populated coastline that is
located on the San Andreas fault line (Fig.2),
making it at risk of
earthquakes because Fig. 2. San Andreas Fault
of the conservative
plate margin.
The state of California has high level of economic wealth,
being ranked in the top ten economies compared with the
Russian Federation and Italy, all with a GDP of $2 trillion.
The high levels of economic development in California have
led to vast urban areas, which are densely populated—the
most densely populated county being San Francisco with
almost 3,500 per square mile. For these reasons, the
impacts of any major disasters which occur in California,
will be mainly economic losses, for example, the San
Francisco earthquake of 1989 which resulted in insurance
claims of $680 million and only 62 fatalities, and not result
in deaths like the Haiti 2010 earthquake (225, 000). This can be explained by the
disaster risk equation and when applied to California results in a high disaster risk due
to a high vulnerability from hazards but a high coping capacity due to earthquake drills
etc. Therefore, while any major hazards wouldn’t cause a high death toll, California
would be greatly affected economically through destruction to infrastructure and
insurance claims.
The location of California which is part of the Pacific Ring of Fire—where a large number
of volcanic eruptions and earthquakes occur in the Pacific ocean basin— and on the
boundary of the Pacific and North American plates results in the regular occurrence of
geophysical hazards, specifically earthquakes and tsunamis. In this particular plate
boundary, the two plates are moving in the same direction, although the Pacific plate is
moving at a rate which is 6 times faster. It is this difference which causes a build up in
friction, the energy of which is released as seismic waves as the plates jerk past each
other. This results in earthquakes which occur with a high frequency, however, major
earthquakes (7 or higher on the Richter scale) such as the 1906 San Francisco
earthquake— which caused more than 3000 fatalities and destroyed 80% of San
Francisco, having a magnitude of 8.2), only occur every ten or so years.
Furthermore, there is the risk of liquefaction in the San Andreas fault area, which was a
major factor in the level of destructing caused by the 1989 San Francisco earthquake.
Liquefaction is where softer sediments such as sand lose their strength and form into a
liquefied state in response to external force such as the shaking of an earthquake. This
greatly increases the impacts of earthquakes to urbanized areas as it can magnify
structural damage to building etc. by causing them to suddenly lose strength and
structure. Liquefaction was experienced during both of the San Francisco earthquakes,
particularly intensifying shaking in the Bay Area.
A disaster hotspot is an area that is extremely at risk due to the fact that it is prone to
multiple types of hazards and that it overlaps
Fig. 1.Dregg’s Disaster Model with a vulnerable population shown by Dregg’s
Model (Fig.1) California is considered to be a
disaster hotspot, which has a very high disaster
risk due to its high vulnerability as a result of its
highly densely populated coastline that is
located on the San Andreas fault line (Fig.2),
making it at risk of
earthquakes because Fig. 2. San Andreas Fault
of the conservative
plate margin.
The state of California has high level of economic wealth,
being ranked in the top ten economies compared with the
Russian Federation and Italy, all with a GDP of $2 trillion.
The high levels of economic development in California have
led to vast urban areas, which are densely populated—the
most densely populated county being San Francisco with
almost 3,500 per square mile. For these reasons, the
impacts of any major disasters which occur in California,
will be mainly economic losses, for example, the San
Francisco earthquake of 1989 which resulted in insurance
claims of $680 million and only 62 fatalities, and not result
in deaths like the Haiti 2010 earthquake (225, 000). This can be explained by the
disaster risk equation and when applied to California results in a high disaster risk due
to a high vulnerability from hazards but a high coping capacity due to earthquake drills
etc. Therefore, while any major hazards wouldn’t cause a high death toll, California
would be greatly affected economically through destruction to infrastructure and
insurance claims.
The location of California which is part of the Pacific Ring of Fire—where a large number
of volcanic eruptions and earthquakes occur in the Pacific ocean basin— and on the
boundary of the Pacific and North American plates results in the regular occurrence of
geophysical hazards, specifically earthquakes and tsunamis. In this particular plate
boundary, the two plates are moving in the same direction, although the Pacific plate is
moving at a rate which is 6 times faster. It is this difference which causes a build up in
friction, the energy of which is released as seismic waves as the plates jerk past each
other. This results in earthquakes which occur with a high frequency, however, major
earthquakes (7 or higher on the Richter scale) such as the 1906 San Francisco
earthquake— which caused more than 3000 fatalities and destroyed 80% of San
Francisco, having a magnitude of 8.2), only occur every ten or so years.
Furthermore, there is the risk of liquefaction in the San Andreas fault area, which was a
major factor in the level of destructing caused by the 1989 San Francisco earthquake.
Liquefaction is where softer sediments such as sand lose their strength and form into a
liquefied state in response to external force such as the shaking of an earthquake. This
greatly increases the impacts of earthquakes to urbanized areas as it can magnify
structural damage to building etc. by causing them to suddenly lose strength and
structure. Liquefaction was experienced during both of the San Francisco earthquakes,
particularly intensifying shaking in the Bay Area.
