What Would a Devastating Earthquake in California Look Like? An example is the magnitude 6.2 earthquake that hit New Zealand on Feb. 22, 2011, that left physical, economic and psychological aftershocks that continue. The quake redrew the geography of Christchurch, which is flatter and smaller now. Some excerpts:
The Christchurch rebuild is expected to cost $26 billion, according to an estimate by the Reserve Bank, making it New Zealand’s single biggest economic challenge.
“After the earthquake, we all sort of thought — oh, five years and the central city will be back to normal. And it was oh, probably 10. And then 15. And then 20. And so it goes on,”
The economic blow for many was lessened by New Zealand’s high rate of earthquake insurance.
Earthquakes Still Surprise Us, Even with All the Science. None of the detection equipment or computer-generated models helped geologists predict the 4.5 magnitude earthquake that rolled through Pleasant Hill, Calif., Monday night. The fault shook 70,000 people in the region.
From HSToday: Mayor Orders San Francisco to Prepare for the Big One: 72 Percent Chance Before 2043
According to a statement from the Office of Mayor London Breed, “It is estimated that San Francisco has a 72 percent chance of experiencing a 6.7 magnitude or greater earthquake before 2043.”
Breed says, “We know that the next major earthquake will hit at any time and every day we should be working to prepare for it,” announcing that she is ordering city organs to “make our buildings safer now, but also [create] a comprehensive plan” for recovery in the face of an eventual disaster.
CRS report on the National Earthquake Hazard Reduction Program. Dec. 2018.
The federal government has supported efforts to assess and monitor earthquake hazards and risk in the United States under the National Earthquake Hazards Reduction Program (NEHRP) since 1977. Four federal agencies responsible for long – term earthquake risk reduction coordinate their activities under NEHRP.
U.S. Geological Survey (USGS)
National Science Foundation (NSF)
Federal Emergency Management Agency and
National Institute of Standards and Technology (NIST).
On November 27, 2018, Congress passed the National Earthquake Hazards Reduction Program Reauthorization Act of 2018 and sent the bill to President Trump on November 29. The 2018 NEHRP reauthorization act largely leaves the overall program structure in place, but modifies some of the intents and purposes of the original legislation, such as removing references to the goal of earthquake prediction, and substituting instead the goal of issuing early warnings and earthquake alerts. The new law also authorizes appropriations for NEHRP activities for each of the four NEHRP agencies through FY2023.
The Anchorage Earthquake Was Terrifying. But the Damage Could’ve Been Much Worse.
Experts said that while the quake was significantly less intense than the one in 1964, which was magnitude 9.2, its limited destruction was the result of the region’s growing smarter and much more resilient in the years since. Anchorage was much better prepared for a major earthquake; other cities may not have fared so well.
The Diva looked for TV coverage of the earthquake, but there was little to see over the past few days. News of the G20 Summit and the death of Pres. Bush got all the attention.
More news from down under, this time an article about post-earthquake resilience in Christ Church, NZ. See: Engineering expert scoops top South Island property award.
Thanks to Ian McLean of NZ for the citation.
From Scientific American: Indonesian Tsunami Was Powered by a Deadly Combo of Tectonics and Geography. The magnitude 7.5 earthquake that touched off the tsunami occurred amid a complex puzzle of tectonic plates.
Thanks to Ian McLean of New Zealand for this citation. He says that NZ also has similar tectonic conditions. Here are some of his observations about the seismic conditions and risk in New Zealand.
What I found particularly interesting was the fact that the earthquake occurred in a transition zone. To the west of this zone one plate subducts, and to the east of the zone the plates abut pushing up mountain ranges.
The configuration is similar to the zone in New Zealand where the Kaikoura sequence of earthquakes occurred.. To the north the Pacific plate subducts the Indo-Australian plate; and to the south the plates abut, pushing up the Southern Alps.
In the transition zone is a complex jumble of faults. Several of these ruptured sequentially during the Kaikoura sequence. The damage was unexpectedly severe, especially in Wellington.
But NZ still awaits with apprehension earthquakes along the plate boundaries to the south and north of the transition zone. To the south , the Alpine fault has reached its mean return period. In the north, knowledge about the HIkurangi subduction zone was sparse, but substantial research is now being done.
Ian McLean is a former Chair of NZ Earthquake Commission, and has advised on catastrophe insurance schemes around the world, including helping to form the schemes in Turkey and Romania through the World Bank.
From Bloomberg News: Getting a Jump on the Next Big Earthquake. The $38 Million Earthquake Alert System Can Buy the West Coast Precious Seconds.
From the NYTimes: San Francisco’s Big Seismic Gamble
San Francisco lives with the certainty that the Big One will come. But the city is also putting up taller and taller buildings clustered closer and closer together because of the state’s severe housing shortage. Now those competing pressures have prompted an anxious rethinking of building regulations. Experts are sending this message: The building code does not protect cities from earthquakes nearly as much as you might think.