TO:
Honorable Mayor and Members of the City Council
THROUGH:
David N. Carmany, City Manager
FROM:
Robert Espinosa, Fire Chief
SUBJECT:Title
Proclamation declaring March 24-30, 2013, as Tsunami Preparedness Week
PRESENT
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Recommended Action
RECOMMENDATION:
Staff recommends that the City Council recognize and proclaim March 24, 2013, through March 30, 2013, as “Tsunami Preparedness Week” in Manhattan Beach and encourage all residents to increase their knowledge and awareness of proper safety measures to follow before, during, and after tsunamis.
Body
FISCAL IMPLICATIONS:
There are no fiscal implications associated with the recommended action.
BACKGROUND:
Tsunamis are typically generated by underwater earthquakes - landslides, volcanic activity, and meteor strikes are other known, but less common, tsunami sources. Tsunami generating earthquakes usually occur in subduction zones, such as those found in the Pacific Ocean off the U.S. western and Alaskan coasts. Marked by deep trenches in the seafloor, subduction zones are formed where one of the earth’s outer shell of tectonic plates plunges underneath another. Usually the plates are gradually moving past each other, but friction may temporarily lock them together, causing stress to build up between the plates. Sometimes the stress is relieved suddenly in the form of a large earthquake. As the bottom plate dives farther down, causing the top plate to snap upward, the overlying seawater is disturbed. The size of the resulting tsunami depends on several factors such as the size of the earthquake, its depth below the ocean floor, the depth of the water, the type and amount of seafloor movement and the energy released.
The West Coast/Alaska Tsunami Warning Center in Palmer, Alaska, is responsible for warning Alaska, both west and east coasts, and states along the Gulf of Mexico. It uses two types of warning data for determining when to issue a tsunami warning. First, they receive and analyze earthquake data from seismic networks operated by the National Oceanic and Atmospheric Administration, United States Geological Survey, states, and universities to determine whether to issue a warning. If the seismic data indicate that a local tsunami may be generated, the center issues a warning based on the earthquake data alone. Second, the warning center analyzes sea-level data to determine whether a tsunami has actually been generated, and if not, cancels the warning.
DISCUSSION:
Tsunamis from both local and distant earthquakes threaten Southern California coastal communities. Although our oceans are monitored for developing tsunamis, when a large earthquake occurs nearby, the first tsunami wave may reach coastal communities, such as Manhattan Beach, within a few minutes of the event.
Local populations at risk must be able to recognize the signs of impending tsunami hazards and seek higher ground immediately. While distant-source tsunamis give residents more time to evacuate threatened coastal areas, they increase the need for timely and accurate assessment of the tsunami hazard to avoid costly false alarms.
Residents need to be aware of what areas are likely to be flooded and about the multi-hazard ramifications of potential disruption caused by very large local and distant earthquakes.
This is why the City wishes to recognize Tsunami Preparedness Week and encourages all residents to increase their knowledge and awareness of proper safety measures to follow before, during, and after a tsunami.
Information including the basics of tsunamis, lessons learned from the March 11, 2011, Japan earthquake and tsunami, and what local residents can do to be prepared will be discussed during the town hall on March 28, 2013, at 6:30 p.m. at the Joslyn Community Center.
Attachment:
1. 2013 Tsunami Preparedness Week Proclamation