Alaska researchers claim that most of Anchorage is safe from danger of a tsunami however, they warn that the wave could be devastating to Girdwood, Hope and some other areas of the coast, including Alaska’s Port of Alaska, under certain conditions.
This is according to the first-of-its-kind hazards simulation for Upper Cook Inlet in the report released today by the Alaska Earthquake Center, the state Division of Geological and Geophysical Surveys and the state Division of Homeland Security and Emergency Management.
The threat of a major tsunami affecting Anchorage which is Alaska’s biggest city situated at the point of Cook Inlet – has been the topic of discussion for a long time. Following several earthquakes near the city in the last decade, there has been uncertainty about the frequency of alerts to warn residents they’re in danger. Geologists have stated that most Anchorage people are secure from tsunamis but there hadn’t been a comprehensive study prior to the latest report, released on Wednesday, that includes updated and detailed inundation maps.
“One important thing this report does is to debunk the myth that there’s no chance that a tsunami will be able to reach Anchorage. We know this isn’t the case,” state Earthquake and Tsunami Hazards Program Manager Barrett Salisbury said. “There are coastal areas with low levels which could be flooded by high tide. However, the majority of homeowners are located in Anchorage and the surrounding areas won’t need to be worried about their homes and property.”
In the study should a large enough earthquake occurs in the correct spot at the appropriate moment – for instance the time of a high tide in the Upper Cook Inlet – a tsunami could sweep across the coastline in the Anchorage region, including at the Port of Alaska and along Ship, Chester and Fish creeks. In addition, the report states that an earthquake can trigger the occurrence of a localized landslide within Cook Inlet, which itself could result in a rapid-moving tsunami.
The authors of the study said at the press conference on Wednesday that the possible effects of the tsunami on the port aren’t clear and will require more study. Around 75% of all water-borne cargo to Alaska is brought into the state via Anchorage, which is the Port of Alaska, in Anchorage.
Anybody who is near the coast where a large earthquake is likely to strike must always be alert to the possibility of a tsunami, researchers wrote.
However, in Anchorage the area, there could be ample time to inform people of tsunamis caused by earthquakes because according to the report Cook Inlet’s shallow waters could result in an extremely slow-moving wave.
The report’s authors modelled the magnitude of Alaska’s 9.2 1964 Good Friday Earthquake – the second-largest recorded earthquake – and discovered that a 10-foot-wide wave could was spotted on the coastline of the city for more than eight hours following the earthquake. The tsunami was not detected according to the report since it struck in the middle of night, and was accompanied by an outgoing tide, which slowed the effect of the tsunami.
In a possible, scenario that is described by the authors, a massive earthquake could hit the point of entry of Cook Inlet as the tide is rising, causing powerful currents and high levels of water. The latest maps of flooding show the most significant impacts would include flooding within areas like the Turnagain Arm communities of Girdwood and Hope and also across the Knik Arm, which is located between Anchorage within Anchorage in the Point MacKenzie area.
Despite the ongoing confusion and uncertainty due to tsunami warnings that are constantly buzzing the phones of residents due to “overalerting,” as one researcher explained – massive earthquakes are expected to continue to cause warnings for the whole Anchorage region, at least at least for now.
Dave Snider, warning coordinator for the National Tsunami Warning Center in Alaska He said that his organization is working to resolve the problem.
“So at present, we’re hampered by our ability to identify specific parts of our geographic area,” Snider said. “And in the near future we’ll be able alert specific areas of our coastlines, including our Anchorage coastline. At present the limitations we have are likely to alert to a greater number of people than they actually require them to leave the coastline.”
