As published in Nature, here. Oh, wait, that’s 9PM Jan 26th *1700*, as estimated from Japanese tsunami records:
But just in case I don’t think I’ll be working late in PLC on Tuesday night.
As published in Nature, here. Oh, wait, that’s 9PM Jan 26th *1700*, as estimated from Japanese tsunami records:
But just in case I don’t think I’ll be working late in PLC on Tuesday night.
A couple of comments here:
1. The magnitude of this latest event was likely larger than 9 but probably not large than 9.5 – equivalent to the Chilean earthquake of 1960
2. https://pnsn.org/blog/2013/01/24/the-last-cascadia-great-earthquake-and-tsunami-313-years-and-ticking – is a good reference
3. http://activetectonics.coas.oregonstate.edu/earthquakes.htm – an even better reference – read this and be informed
4. Starting in 7800 BC here are the magnitude 9+ occurrences and time intervals between them
7800 BC
7100 BC — 700 years
6800 BC — 300 years
6100 BC — 700 years
5600 BC — 500 years (Mazama erupts 100 years later)
5100 BC — 500 years
4400 BC — 700 years
3900 BC — 500 years
2800 BC — 1100 years
2100 BC — 700 years
1500 BC — 600 years
1100 BC — 400 years
600 BC — 500 years (air, earth, fire and water)
100 BC — 500 years (hooray for Lucretius)
400 AD — 500 years (fall of Rome)
600 AD — 200 years
1200 AD — 600 years
1500 AD — 300 years
1700 AD — 200 years
so yes, it looks like frequency is increasing over last 2000 years
I’m no geologist, but I wonder if the apparent increased frequency is an artifact of detection bias, i.e., more recent quakes leave more easily detected signatures.
The State of Oregon should call Jan 26th “Subduction Day” and use it to practice earthquake safety.