The eruption of an undersea volcano in the South Pacific sent tsunami warnings around the globe over the weekend but Santa Monica escaped any significant damage.
At 6:09 a.m. on Jan. 15 the National Weather Service issued a tsunami warning for the entire West Coast, however the day passed with no major incidents locally and the warning was lifted by 12:30 a.m. the following morning. While groups of eager surfers ignored warnings to avoid the water, they were met with unremarkable waves of two to three feet.
The largest area of impact regionally was the Santa Cruz harbor, where the tsunami waves combined with the high tide flooded the adjacent parking lot and streets. In Marina del Rey a pair of boats tore loose from their moorings and damaged a dock.
Santa Monica is well protected from most potential tsunamis. The Catalina Islands provide some protection out to sea and shoreline defenses include wide beaches and high bluffs. A majority of the city’s construction is located above sea level, meaning potential flooding is limited to a section of town along the southern edge and sea level houses along the Pacific Coast Highway.
Some of the City’s infrastructure has also been improved over time to help protect against dangerous waves. The Santa Monica Pier withstood some heavy storms 40 years ago that prompted improvements such as concrete pilings.
Venice and Marina del Rey are at higher risk of flooding due to a tsunami as large portions of these neighborhoods are located at sea level. The tsunami evacuation zone in Venice includes all of the beach adjacent areas, the canals, and most streets west of Abbot Kinney Boulevard. All of Marina del Rey west of Thatcher Avenue is considered a tsunami hazard zone.
The local hazard zones were generated after international disasters prompted analysis of local threats.
The local shoreline has two kinds of tsunami threat, local and teletsunami.
A local event would be caused by a nearby earthquake. It would arrive within minutes to an hour and residents would likely have felt an earthquake. In that scenario, beachgoers should not wait for emergency notification. Any sign of an earthquake should prompt locals to leave the beach and seek higher ground. While it might arrive quickly, a local quake is the lesser of the two dangerous.
More threatening would be a teletsunami generated by a faraway earthquake under the sea. The disastrous 2011 tsunami that devastated parts of Japan was a teletsunami that overwhelmed coastal defenses and the threat has prompted California officials to create expanded tsunami hazard maps and disaster preparation efforts (www.tsunami.ca.gov).
Despite the relatively low local danger, local officials have said it is important for all residents to be aware of warning signs and what to do in the event of an emergency. These signs include a rapidly receding shoreline, unusual waves and sounds, and strong currents. Contrary to many people’s understanding, tsunamis are not one major wave and may present as sloshing walls of water that continue all day.
Residents are advised to sign up for the City’s local emergency notification system by texting “SMalerts” to 888777 or visiting SMalerts.net. In the event of a tsunami residents should seek higher ground by foot to avoid getting trapped in a car.