Dec 23, 2022 05:27 PM
(This post was last modified: Dec 23, 2022 05:37 PM by C C.)
https://www.newsweek.com/california-dodg...dt-1769113
EXCERPTS: California may have just dodged a devastating tsunami after a [lesser] 6.4 magnitude earthquake shook Humboldt County early on Monday morning. At least two people died in the 11-mile-long earthquake, which hit off the far North Coast of California, with a dozen more injured. Power outages swept across the region and many houses were damaged.
The region is extremely tectonically active, as it is located at the southern end of the Cascadia subduction fault—where the United States sits right over the ocean floor. The fault lies at the northern tip of the San Andreas fault, the border section between two massive tectonic plates under the Earth's surface.
[...] When earthquakes happen along this boundary, "they can be huge," Simms said. The enormity of this event [a magnitude 8 or 9 quake and subsequent tsunami] would be on par with the magnitude 9.1 earthquake and tsunami that hit Tōhoku, in Japan in 2011.
[...] Aftershocks from the 6.4 magnitude earthquake are still rippling out across the region. The U.S. Geological Survey estimates that there is a 4 percent chance these aftershocks will be of a magnitude 5 or larger, which can happen following large earthquakes.
It is more likely, though, that eight magnitude 3 aftershocks will occur in the next week. Magnitude 3 aftershocks will not be as damaging as magnitude 5, but are big enough to be felt.
[...] In the meantime, seismologists are continuing to keep a close eye on the fault.
"While we can't issue advance warning of an earthquake about to happen yet, we can and do have a system to detect the earthquake as it begins and send out alert messages—this is the ShakeAlert earthquake early warning system, operated by the USGS in partnership with us at the University of Washington, as well as CalTech, and UC Berkeley," Tobin said... (MORE - missing details)
EXCERPTS: California may have just dodged a devastating tsunami after a [lesser] 6.4 magnitude earthquake shook Humboldt County early on Monday morning. At least two people died in the 11-mile-long earthquake, which hit off the far North Coast of California, with a dozen more injured. Power outages swept across the region and many houses were damaged.
The region is extremely tectonically active, as it is located at the southern end of the Cascadia subduction fault—where the United States sits right over the ocean floor. The fault lies at the northern tip of the San Andreas fault, the border section between two massive tectonic plates under the Earth's surface.
[...] When earthquakes happen along this boundary, "they can be huge," Simms said. The enormity of this event [a magnitude 8 or 9 quake and subsequent tsunami] would be on par with the magnitude 9.1 earthquake and tsunami that hit Tōhoku, in Japan in 2011.
[...] Aftershocks from the 6.4 magnitude earthquake are still rippling out across the region. The U.S. Geological Survey estimates that there is a 4 percent chance these aftershocks will be of a magnitude 5 or larger, which can happen following large earthquakes.
It is more likely, though, that eight magnitude 3 aftershocks will occur in the next week. Magnitude 3 aftershocks will not be as damaging as magnitude 5, but are big enough to be felt.
[...] In the meantime, seismologists are continuing to keep a close eye on the fault.
"While we can't issue advance warning of an earthquake about to happen yet, we can and do have a system to detect the earthquake as it begins and send out alert messages—this is the ShakeAlert earthquake early warning system, operated by the USGS in partnership with us at the University of Washington, as well as CalTech, and UC Berkeley," Tobin said... (MORE - missing details)
