Tsunamis are a series of very long ocean waves usually caused by undersea earthquakes or other events that disturb a significant amount of ocean water. The West Coast of the United States, Hawaii and Alaska are particularly prone to tsunamis, with potential threats around the Pacific Rim. At least 30 reported tsunamis caused at least one death or $1 million in damage in the United States in January 2018, according to NOAA.
“Every tsunami is very tricky…we learn something new every time,” said Rick Wilson, co-chair of the Tsunami Science and Technology Advisory Panel (TSTAP), a group of non-federal scientists who published the report and a branch of NOAA Science. Advisory Board. “However, we believe that these recommendations in the future will not only save lives, but potentially millions of dollars in future trade and coastal tsunami risk protection.”
The 32-page report outlines several areas for improvement, but the most pressing issues relate to NOAA’s tsunami warning program and its two tsunami warning centers, located in Honolulu and Palmer, Alaska. Namely, the report highlights “perceived gaps and inconsistencies throughout the tsunami forecasting and warning process.” Some of the recommended changes are significant and described as “overhaul” to ensure accurate, timely and clear warnings of impending tsunami waves.
This year’s report builds on a broad 2011 assessment by the National Academy of Sciences, which found numerous gaps in the country’s tsunami preparedness and opportunities for improvement, detailed in a long list of recommendations. nearly 200 pages.
Although progress has been made on a number of fronts, many key issues remain unaddressed or have not kept pace with technological change, or new issues have emerged.
“Obsolete” warning system requiring an update
The panel took a close look at the global warning system: from the source of the tsunami, to the forecasts, to the messages sent to the public.
“We discovered that some parts of [the] system they have in place right now are somewhat outdated and not capable of delivering the changes that many states and communities are asking to change,” Wilson said.
For example, the two tsunami warning centers in Alaska and Hawaii rely on outdated software and methods, which limits the improvement of the warning process, including the estimation of generation potential waves from earthquakes and other sources. As new complex warning issues have surfaced over the years, patchwork or “band-aid” fixes have been applied.
The Hunga Tonga volcanic eruption and resulting tsunami on January 15 in the South Pacific revealed an issue the panel had previously identified: that NOAA should improve its ability to detect and warn of tsunamis from sources not earthquakes, such as volcanic eruptions and landslides.
For example, because the system is set up to estimate earthquake-generated tsunamis, tsunami advisories were issued for Hawaii and the west coast of the United States relatively late, Wilson said.
“Each passing day, year or 10 years makes it more likely that we have a bigger event that will really test the system,” said Corina Allen, chief risk geologist at the Washington Geological Survey and panel member. .
What is needed, according to the report, is a “comprehensive enterprise-wide technology upgrade” of the alert system.
For example, the group’s co-chair, Rocky Lopes, suggested that the centers could have their warning capability unified under the umbrella of the National Weather Service and integrated into its early warning platform (known as AWIPS), which is used to issue timely alerts. for all weather events. In the analysis of seismic events, the expert group recommended greater collaboration with the US Geological Survey (USGS), which uses newer earthquake analysis software than that available in the centers of earthquakes. alert.
Two alert centers, confusing messages
The two NOAA tsunami warning centers cover two distinct regions. The National Tsunami Warning Center (NTWC) serves Alaska, Canada, and the contiguous United States, while the Pacific Tsunami Warning Center (PTWC) covers the Hawaiian Islands, United States and United Kingdom territories in the Caribbean and Pacific, as well as international Caribbean and Pacific coasts.
A long-standing problem is that the two centers are uncoordinated and do not speak with one voice. It is also difficult for one center to step in and perform the functions of the other if one center is temporarily out of service.
“The warning centers have very good people and very good scientists, but they operate independently,” said Lopes, a former administrator of the national tsunami risk mitigation program.
As a result, they may interpret the same event differently or offer different products to their respective regions. For example, the NTWC provides estimated wave heights in Alaska and the West Coast, which states and communities have found useful for response efforts and to better assess tsunami risk. However, the PTWC does not provide this information to its service areas.
Tsunami.gov, the website that serves as the official warning repository for all tsunamis, was established in 2016 and collects warning information from each center in near real-time bulletins. But when a major earthquake occurs, the nature and extent of any potential tsunami threat is far from clear.
“It’s not a user-friendly website,” said Allen of the Washington Geological Survey. “If you’re going there for the first time to try to track these newsletters, it’s really confusing.”
According to the report, a global update to the Tsunami.gov website is needed and could provide a single national message to summarize the scope of each event. Lopes said the lack of attention to Tsunami.gov is likely due to a lack of staff, which the panel hopes NOAA will address in its response to the report.
Earlier warnings are needed for distant tsunamis
Warning centers issue initial warnings of possible tsunamis within five minutes of an earthquake, but it can take up to three hours to produce a full forecast with estimated wave heights for more distant coastal areas from the source of the waves. This is a problem for coastal emergency managers who need to make important evacuation decisions quickly.
“What we’ve found is that many emergency managers still need about three or four hours at a minimum to complete their evacuations and response activities,” said Wilson of Tsunami Science and Technology Advisory Panel.
On July 28, 2021, following an 8.2 magnitude earthquake off the coast of Alaska, the threat to the west coast was listed for several hours as “under assessment”, leaving little time to initiate evacuation plans if they were needed.
The committee recommends that NOAA provide an estimate of likely impacts on states much sooner. It also highlights new technologies that can quickly detect tsunamis on the high seas, such as global navigation satellite systems, which could help speed up the warning process and could be more cost-effective than the current network of ocean buoys. used.
The NOAA administrator has one year from January, when the report is received, to respond to the recommended changes. In a letter sent a day after it was received, NOAA Administrator Rick Spinrad wrote, “Please pass on my thanks to TSTAP for their diligence and careful attention to this important matter. We will give this report the attention and follow-up it deserves.