Hopefully we landed on something useful to people! We definitely landed on more questions for the future…..

… a lot of recent developments in seafloor technologies and imaging approaches, where traditionally more siloed techniques are overlapping in their frequencies. Overall, was a fun excuse to dive into some of the weirdnesses of OBS data that @jbrussell.bsky.social and I have pondered for years!

4. Overall there’s still a lot more work to be done to understand what exactly is happening with ambient noise wave propagation recorded on OBS at periods <10 s, what that means for the depth sensitivity of observations, and implications imaging applications. And it’s an exciting time as we have…

3. You can absolutely accidentally remove your signal from ambient noise cross correlation functions at longer periods with transfer function techniques if you’re not careful, but it’s pretty straightforward to assess if this is an issue in your dataset via SNRs.

2. Leveraging short period ambient noise measurements is a lot easier if you’re in the deep open ocean, although similar quality data is certainly possible in shallower more coastal settings.

1. Shallow structure matters, especially at shorter periods. While this has likely been obvious in some imaging communities for quite a while, passive OBS arrays are more recently using shorter periods. That helps constrain crustal structure with passive methods, but care is needed.

The ability to do this requires continued investment and improvement in monitoring instrumentation, data collection, modeling, basic scientific research, and emergency management agencies. And international collaboration and communication is essential, since tsunamis do not care about borders.

So while this time was a success, it’s absolutely not the time to become complacent. And it’s worth remembering that the 1946 tsunami spurred the creation of the Pacific Tsunami Warning Center, which today, along with other organizations, still issues warnings to communities around the Pacific.

I received first official emergency alerts about an hour after the earthquake, although I was already glued to NOAA’s tsunami website by that point. So take an hour off that travel time for people to start responding, you have 3.5-4 hrs, that 3 hours of gridlock traffic starts to not look so good.

In fact in 1946 one did, and the waves were much bigger reaching around 55 ft in places in Hawaiʻi. sos.noaa.gov/catalog/data.... While this is the largest and most destructive tsunami in modern history here, other Aleutian earthquakes have also occurred generating tsunamis.

Thank you!!

Fresh from the press, so to speak, a result of our #tsunami model based on the specifics of this earthquake (we will update it one we have more model runs). The color code is wave height in metres. The dotted line in the centre of the picture is the Hawaiian island chain.