Hacker News Reader

Hacker News

Comment by doublerebel | Hacker News Reader

Full thread

doublerebel

Everyone in the Seattle region is thinking about earthquakes since we just felt the 4.3 quake on Sunday!

https://www.seattletimes.com/seattle-news/environment/small-...

View on HN

Felt it up here in Victoria, too.

I can't readily find a source, but there was another one some weeks back of around 4.0.

I can't decide if these are good news making a big quake less likely or foreshadowing of a big quake coming.

There is little evidence that earthquakes come as precursors to larger earthquakes. Most papers reporting such things have selection bias since they are written after the big earthquake occurred.

It's more the other way around. A large earthquake is often followed by a swarm of aftershocks, some of which can cause significant damage.

The media failed to report that the recent quake in Morocco was followed by tens of smaller quakes over the next few weeks, all in a small-ish area that had been quake-free. (In recent memory, at least.)

A fault is a series of hooks, nooking into the oppossing plate. One of them giving way, in a small event, gives off its energy partially to the surroundings (the quake) - the rest- stays as additional pressure on another rockformation.

There is a lot of research on people not taking possible disasters serious: https://en.wikipedia.org/wiki/Normalcy_bias

Its understandable, but in the end also just noise for those who do and want to discuss mitigiation strategies or statistics. The urge to conjur up security by repeating doubt mighte be huge, but like all prayer, should be kept to oneself.

i don't really think this is a fair conceptual model for a fault nor for how an earthquake nucleates progresses and then ends. it doesn't really account for plastic deformation, fluids, the interface media (a fault has more than just two rocks touching each other, there is typically some amount of ground up particles, etc that sits at hte interface). there are faults that move aseismically (e.g., the subduction zone in mexico) that do not produce earthquakes at all. faults are a rather complex system that isn't really just hooks connected across an interface. i guess this description could be considered an asperity.

Yeah, I'm in Kingston so felt that one plenty. It was a weird one: less rumble, more a sudden jolt that shook the floor. Really weird.

Didn't feel a thing (2) in North Seattle.

Definitely felt it for a couple seconds lying still. If you were driving or moving about you might've missed it.

Aftershock of Taylor Swift concert?

Didn't feel a thing.

Reply on news.ycombinator.com