Earthquake off Northern California

merger writes "A 7.0 earthquake (7.4 according to NOAA) occured off of the northern California coast occured at 7:50 p.m. PST triggering a tsunami warning (which was then downgraded to a tsunami bulletin). While searching Google News for information I learned about an earthquake preparedness study for the area which was just published today."

East Bay Check In

[obsol33t]

Nothing felt here, most people will not even know about it until tomorrow in our area.

This wasn't anything major.

[FireballX301]

Link to CNN [cnn.com] article.

Plates shifted, relatively high richter scale, but keep in mind the Richter scale is *not* a linear scale. Nothing like the big tsunami a few months back.

Hell, I live in San Diego, I felt a 5.6 a few days ago. Shook my bed a bit, that was more of an event than this.

Tsunami info from a former park ranger

[bjackrian]

I worked as a Park Ranger at Redwood National Park a few years ago, and this is one of their nightmare scenarios. My housemate was a geology major, and the area right off of the coach is very susceptible to huge earthquakes (8.0+)--one happens every 200 or so years on average. The last one happened around 1700, so another one is fairly likely in the near future.

Towns like Crescent City are at huge risk, and the city and state are trying to compensate with warning systems (that have been improved since the tsunami in the Indian Ocean). While some buildings have been constructed to withstand tsunamis (the national park headquarters was designed as a "flow through" building so tsunami waves will just break out the first floor windows and flow through the building), the best advice is to climb. Get to high ground as soon as you feel the earth shake. Don't wait for a tsunami warning--just climb!

Also, don't go back to the ocean until you know for sure that it's safe to do so. Apparently, many of the deaths in the 1960s tsunami were a result of the mayor and several other people going down onto a pier to suvery the damage. Because tsunamis are really sets of high waves and sea levle changes, the next set of waves washed them away.

One more interesting tidbit--most tsunami deaths aren't caused by the water itself. Instead, what happens is that the water crashes into buildings destroying them. Additional waves then take all of that debris and use it like battering rams to destroy more buildings. It's the debris that most often causes human deaths and damage in the city. Perhaps a good case for building more tsnuami-safe buildings?

The Map didn't forcast it

[tod_miller]

http://pasadena.wr.usgs.gov/step/ [usgs.gov]

If you look now though, there are two areas of fairly high risk.

Don't use this map for anything important, like planning picnics.

Still, I check this every day, and I am suprised that I was given a reference to test its accuracy so soon.

Still, it has updated today in light of the events.

False Alarm

[amcox]

According to a friend who is a geologist, the quake was on a slip fault, not a thrust falt, and therefore could not produce a tsunami. And, since it was something like 70 miles offshore, the shaking itself didn't do any real damage, either.

Re:This wasn't anything major.

[d474]

It was a major earthquake (7.0), but as far as the tsunami goes, since this latest one was a strike-slip movement, there was practically no tsunami at all. That means the plates moved horizontally against eachother. It's the vertical moving dip-slip fault earthquakes you need to worry about for tsunami's.

here is another good site for seeing all of our

[downsize]

quakes: http://quake.wr.usgs.gov/recenteqs/ [usgs.gov]

you can see this big one off to the upper left, but 'quakes are no big thing around these parts - just look, we get ~hundreds a day; similar to /. geting 2-300 500 server errors a day.

Link to Realtime Earthquake List

[ahodgkinson]

The USGS [usgs.gov] runs a good site [usgs.gov] that lists all earthquakes, worldwide, with magnitude greater than 2.5. I monitored the list after the tsunami of last December, and it was interesting to see the aftershocks in the following weeks.

In this case the same thing is happening. You'll note in the list that there have already been a number of aftershocks over the past few hours.

They also have a RSS feed, so presumably you could create your own tsunami warning system.

Alaska Got Some Big Ones, Too

[kingofalaska]

I know many people think Alaska is off the coast of California, but I noticed we got a few large ones, too.

" Aleutians rocked by series of big quakes [alaska.edu]

The countless quakes started short after midnight. The biggest one, with a preliminary magnitude of 6.9, struck at 9:10 a.m. Tuesday. There were reports of items falling off shelves in Adak, about 175 miles from the epicenter.

The series of quakes occurred where the Pacific and North American plates collide. Most were in the range of 4.5 and 5.7."

Seems to be a relation.

KoA

Eagle crashes into living room of a Ketchikan home [blogspot.com]

Quake Porn

[commodoresloat]

Courtesy of the US Geological Survey right here [usgs.gov]. Plenty of info that I don't understand, plus pretty maps!

Re:Undersea Cables?

[arivanov]

Yes. But 2h is roughly the time it takes to get alternative capacity running on a friend of mine basis. Been there, done that, hate fishermen.

Re:MJ!

[Mard]

Informative AND Insightful! This is the result of having a religious president. :\

Re:False Alarm

[Anonymous Coward]

From this USGS map [usgs.gov], the centre of the earthquake is closest to a subduction zone, not a slip fault, so theoretically the displacement of landmass could have caused a tsunami, had the magnitude been sufficient.

However, the shaking back and forth itself can cause tsunamis... or would they call that a tidal wave?

Tidal wave is the common (and incorrect) way of referring to a Tsunami. It's misleading, though, as the wave produced is not a product of tides at all and must be - by definition- the product of tectonic activity.

Re:This wasn't anything major.

[Pyrion]

Um, epicenters have no depth. The epicenter is the surface point above where the quake hit. Generally the deeper the quake is, the less damage will be incurred (quake-wise) even right at the epicenter.

Re:You're an idiot for not knowing CAPE.

[Teancum]

If Utah doesn't get tornadoes, then explain the F3 tornado that hit downtown Salt Lake City a couple of years ago? Nice damage to the Delta Center and other fun stuff, and a couple of homes totally destroyed. I'm sure their insurance companies (of the home owners) would like to have scientific confirmation that it is impossible to occur so a claim couldn't be made.

And local TV stations routinely (about once every month or so in the summer) show pictures of an F1 somewhere... sometimes as a waterspout in the Great Salt Lake (where it is somewhat common to be seen... not as common as Kansas, but it does happen). I guess that is just Photoshop, right?

I used to live in Southern Minnesota, and I will admit that tornadoes are much more common there. And in Utah (where I am living now), not only do you have problems with relative energies to produce tornadoes, you also have mountains that tend to muck up any consistant rainfall patterns. It is common for a major storm to dump 2" to 4" of rain in one area and just a trace 10 miles to the north or south. Wind going around a mountain range has similar distortions, all which contribute to breaking up systems that might produce tornadoes.

All that said, and to get this more on topic, I would hate to be near large bodies of water like the Great Salt Lake, Bear Lake, or Lake Powell if an earthquake was triggered underneath. It could certainly produce Tsumai-like effects in a localized area. Or imagine a major earthquake under Lake Michigan and what damage it could do to shoreline properties around that lake. That would be billions of dollars in damage at a minimum.

Still, it is more likely that something would happen in the Pacific (due to "Ring of Fire" combined with the extraordinarly large size of the Pacific Ocean), and why the money is being dumped into warnings for that area of the USA, and not the Rustbelt of the Great Lakes region.

Re:Northern California Coast???

[vought]

California, to my knowledge, has no Northern Coast. So watch out for them land-bound tsunamis or the terrorists have won.

California has about 840 miles of coastline.

You bet we've got a north (Oregon sorth to roughly the Golden Gate), central (Godlen Gate south to Santa Barbara) and south (Santa Barbara on down) coast. North, central, and southern sections represent the general north-south location of that west-facing coastline.

While the coastline in southern california faces southwest and Los Angeles is east of Reno (the state is distinctly boomerang-shaped), most Californians think of the coast as a westerly-facing one.

I don't know about you guys....

[OneSmartFellow]

But if I were living near 'The Geysers', I'd be a little concerned

The area is a caldera, from what I can tell, and it looks like it's ready to blow !!!!!!

1.9 2005/06/14 21:19:08 38.803N 122.814W 2.9 1 km ( 1 mi) NW of The Geysers, CA

3.9 2005/06/14 19:57:00 38.848N 122.823W 3.6 6 km ( 4 mi) NNW of The Geysers, CA

1.7 2005/06/14 18:46:08 38.832N 122.799W 1.3 4 km ( 2 mi) N of The Geysers, CA

1.6 2005/06/14 09:30:10 38.814N 122.809W 4.1 2 km ( 1 mi) N of The Geysers, CA

2.3 2005/06/14 07:32:45 38.822N 122.810W 4.6 3 km ( 2 mi) N of The Geysers, CA

1.0 2005/06/14 03:45:04 37.249N 122.009W 5.8 2 km ( 1 mi) NW of Monte Sereno, CA

1.9 2005/06/13 18:38:38 37.647N 122.043W 5.6 3 km ( 2 mi) E of Hayward, CA

1.2 2005/06/13 14:58:03 37.926N 122.297W 5.1 1 km ( 1 mi) NNE of El Cerrito, CA

1.9 2005/06/13 14:48:43 38.830N 122.808W 2.8 4 km ( 2 mi) N of The Geysers, CA

1.3 2005/06/13 06:56:32 38.176N 121.979W 5.0 8 km ( 5 mi) SSE of Suisun City, CA

1.7 2005/06/13 06:13:25 38.819N 122.798W 3.8 2 km ( 1 mi) NNE of The Geysers, CA

2.4 2005/06/13 06:09:21 38.819N 122.797W 4.0 2 km ( 2 mi) NNE of The Geysers, CA

1.5 2005/06/13 03:55:00 38.720N 122.339W 7.4 19 km (12 mi) NNE of Angwin, CA

1.4 2005/06/13 03:11:26 38.795N 122.829W 3.0 2 km ( 1 mi) W of The Geysers, CA

1.7 2005/06/12 19:41:58 38.810N 122.790W 2.1 2 km ( 1 mi) NE of The Geysers, CA

1.9 2005/06/12 16:55:24 37.303N 122.096W 5.9 5 km ( 3 mi) WSW of Cupertino, CA

2.0 2005/06/12 14:25:53 38.792N 122.749W 4.4 5 km ( 3 mi) E of The Geysers, CA

1.7 2005/06/12 11:23:44 38.827N 122.799W 3.4 3 km ( 2 mi) NNE of The Geysers, CA

1.7 2005/06/12 11:21:42 38.823N 122.828W 3.3 3 km ( 2 mi) NW of The Geysers, CA

1.4 2005/06/12 07:19:53 38.788N 122.970W 4.8 4 km ( 3 mi) ESE of Cloverdale, CA

1.5 2005/06/12 02:35:46 38.706N 122.362W 2.1 16 km (10 mi) NNE of Angwin, CA

1.9 2005/06/12 00:28:32 38.804N 122.809W 3.0 1 km ( 0 mi) NNW of The Geysers, CA

1.7 2005/06/11 18:33:55 38.796N 122.754W 1.6 5 km ( 3 mi) E of The Geysers, CA

2.6 2005/06/11 10:22:38 38.825N 122.825W 2.7 3 km ( 2 mi) NNW of The Geysers, CA

2.1 2005/06/11 08:18:13 38.821N 122.793W 3.8 3 km ( 2 mi) NNE of The Geysers, CA

1.9 2005/06/11 08:03:00 38.823N 122.800W 3.9 3 km ( 2 mi) NNE of The Geysers, CA

Re:on the Richter scale?

[Trollstoi]

Yes. Shindo [answers.com] and Mercalli [unr.edu]

Warning recended 5 1/2 hours ago

[Anonymous Coward]

When you're posting something that can affect people's lives, *please* check the facts. I heard the tsunami warning being recended over the radio at around 9:30 PM PDT. That's 5 1/2 hours before this story was posted.

There's no reason to create fear or panic.

(And for anyone that's interested why a californian's up posting at 3AM, I just saw Batman Begins. It was remarkably good, although I'm tired of watching ninjas as bad guys [oh, and the ninja is from JAPAN people, not Bhutan...] but i digress)

Re:This wasn't anything major.

[CTho9305]

7.0 is definitely a pretty big quake. The Northridge Earthquake [google.com] killed more than 50 people in the Los Angeles area and it was "only" 6.7. There was some pretty [google.com] significant [csun.edu] damage [ewireinsurance.com] . Of course, its epicenter was in an urban area..

Re:Fucking media and their scare tactics

[Anonymous Coward]

In 1964 a tsunami hit California killing 11 people in Crescent City. It was triggered by an earthquake in Alaska. Earthquakes anywhere in the Pacific can generate tsunamis dangerous to California.

The Alaska and West Coast Tsunami Warning Center (US govt. agency) issued a tsunami warning for the entire west coast that lasted for over an hour. That's the most serious warning they issue. If anything, the media didn't cover it enough.

Doubly wrong post.

[jmichaelg]

You're wrong on two counts.

Since the 1700s, not a single earthquake in California that was over 6.5 has caused a tsunami there.

There have been 8 California quakes that have generated tsunamis. [noaa.gov] Though the San Andreas Fault isn't liable to generate a tsunami because it slips to the right instead of up/down, some California quakes are able to generate undersea landslides. Click on the image [mbari.org] on this Mbari page and you'll see a substantial scar left by a landslide off the Santa Barbara Coast.

Secondly, yesterday's quake was north of Cape Mendocino which is at the southern end of a series of subduction faults that head up to Alaska. Unlike transform faults, subduction faults can, and do, cause tsunamis.

If anything, I think the media is ignoring some of the risks. Portions of Monterey Bay have very steep submarine walls. A 7.0 quake centered in the bay could generate a landslide that would send a tsunami towards the low-lying regions in Monterey and Carmel. The best advice for anyone in California who feels a quake while they're near the shore is to climb right away. Don't wait for the media to tell you there's a risk because the warning will come too late. Most of the time climbing will be unnecessary, but sometimes it'll save someone's life.

Re:Backup links ...

[appleLaserWriter]

Exactly right. For the doubters that remain, here is a map of some of the undersea fiber [telegeography.com] that serves the USA west coast.