Preface. A 9.1 magnitude earthquake in Alaska send a tsunami all the way to the California coast and cause at least $10 billion in damage, forcing at least 750,000 people to evacuate flooded areas, destroy port facilities in the Bay Area and Los Angeles [ #7 and #1 ports respectively in terms of the value of import & exported goods], and send water surging up creeks, harbors and canals everywhere. An Alaskan quake of that strength would cause waves up to 24 feet high that would batter California’s low-lying coastal areas with only a few hours of warning.
Alaska tsunamis can also be set off by melting permafrost as McKittrick (2020) explains below.
Alice Friedemann www.energyskeptic.com author of “Life After Fossil Fuels: A Reality Check on Alternative Energy”, April 2021, Springer, “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer, Barriers to Making Algal Biofuels, and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Collapse Chronicles, Derrick Jensen, Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report
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Perlman D (2013) How Alaskan quake could lead to California tsunami. San Francisco Chronicle.
Several historical distant-source tsunamis, including those generated by the 1946 magnitude (M) 8.1 Aleutian, 1960 M9.5 Chile, and 1964 M9.2 Alaska earthquakes, caused known inundation along portions of the northern and central California coast
In addition to inundation, a tsunami could generate strong, unpredictable currents in the ocean close to shore, causing significant damage in harbors and bays. An extrapolation of the damage in California from the 2011 Tohoku tsunami even stronger ones can happen that will damage or sink one-third of the boats and damage or destroy over one-half of the docks in California coastal marinas. Small craft damages would include commercial fishing boats. In northern California, the scenario timing in March is considered the off-season and many fishermen would be away from their boats, which aggravates the exposure of the fleets to the tsunami. Loose boats would become floating debris or sink, posing navigational hazards to other vessels.
Fires would likely start at many sites where fuel and petrochemicals are stored in ports and marinas. Many fires during past tsunamis have been caused when flammable liquids were released, spread by water, and ignited by mechanisms such as electrical leakage, short circuits, and sparks created by pieces of debris colliding.
The tsunami has the potential to cause environmental contamination in both inunda ted areas onshore and the coastal marine and estuarine environments. Potential sources for contamination are many and varied, and include, for example:
debris from damaged piers, ships, commercial and industrial facilities, and large numbers of residences; petroleum products released from damaged ships and inundated or damaged marine petroleum terminals, petroleum storage facilities, marinas, power plants, and airports; raw sewage from inundated wastewater treatment plants; household and commercial building contents (lubricants, fuels, paints, pesticides, fertilizers, electronics); smoke, ash, and debris from fires; runoff from inundated agricultural fields containing pesticides, herbicides, and fertilizers; and redistribution of existing contaminated sedime nts in ports, the near shore marine environment, and in estuaries, sloughs, and bays.
Property damages include about 69,000 single-family-equivalent homes
McKittrick E (2020) Alaska’s new climate threat: tsunamis linked to melting permafrost. The Guardian.
Research shows that mountains are collapsing as the permafrost that holds them together melts, threatening tsunamis if they fall into the sea. Scientists are warning that populated areas and major tourist attractions are at risk.
One area of concern is a slope of the Barry Arm fjord in Alaska that overlooks a popular cruise ship route. The Barry Arm slide began creeping early last century, sped up a decade ago, and was discovered this year using satellite photos. If it lets loose, the wave could hit any ships in the area and reach hundreds of meters up nearby mountains, swamping the popular tourist destination and crashing as high as 10 meters over the town of Whittier. Earlier this year, 14 geologists warned that a major slide was “possible” within a year, and “likely” within 20 years.
In 2015, a similar landslide, on a slope that had also crept for decades, created a tsunami that sheared off forests 633 feet (193 meters) up the slopes of Alaska’s Taan Fiord.
Over the past century, 10 of the 14 tallest tsunamis recorded happened in glaciated mountain areas. In 1958, a landslide into Alaska’s Lituya Bay created a 524-meter wave – the tallest ever recorded. In Alaska’s 1964 earthquake, most deaths were from tsunamis set off by underwater landslides.
References
USGS (2013) U.S. Geological Survey Open-File Report 2013. 1170– A California Geological Survey Special Report 229 The SAFRR (Science Application for Risk Reduction) Tsunami Scenario. U.S. Geological Survey.