August 24, 79 C.E.: Vesuvius had something to say

August 24, 2014

Much as the GOP Caucus and other climate-change deniers, Roman officials in Pompeii and Herculaneum refused to be alarmed at the ground shaking, and obvious eruptions from Mount Vesuvius, on August 24, 79 C.E.

This morning we awake to news of earthquakes in Chile and California. The old Earth keeps rumbling.

Oddly, we now pay more attention to earthquakes than to other things that can cause greater, rolling disasters.

Santayana’s Ghost wonders if we ever learn from history.

Vesuvius, asleep for now. National Geographic photo by Robert Clark

Vesuvius, asleep for now. National Geographic photo by Robert Clark


Oklahoma earthquake swarm, November 2011?

November 6, 2011

Is it enough to call it a swarm?  Oklahoma hadn’t had a quake of great signficance in about 30 years, but they had a 5.6 and a 4.7  yesterday — and look at this list for today and yesterday from the USGS (list will probably change at USGS as time moves on):

MAG UTC DATE-TIME
y/m/d h:m:s
LAT
deg
LON
deg
DEPTH
km
LOCATION
MAP 3.3 2011/11/06 18:26:56 35.478 -96.864 5.0 4 km ( 2 mi) SE of Meeker, OK
MAP 3.7 2011/11/06 17:52:34 35.547 -96.819 5.0 7 km ( 4 mi) S of Sparks, OK
MAP 3.9 2011/11/06 15:07:05 35.535 -96.909 5.0 4 km ( 3 mi) NNW of Meeker, OK
MAP 3.2 2011/11/06 11:20:23 35.525 -96.883 5.0 3 km ( 2 mi) NNE of Meeker, OK
MAP 3.0 2011/11/06 11:16:20 35.523 -96.844 4.9 6 km ( 3 mi) ENE of Meeker, OK
MAP 3.4 2011/11/06 11:03:52 35.539 -96.825 5.0 8 km ( 5 mi) S of Sparks, OK
MAP 3.9 2011/11/06 10:52:35 35.567 -96.797 5.0 5 km ( 3 mi) SSE of Sparks, OK
MAP 4.0 2011/11/06 09:39:57 35.506 -96.865 5.0 3 km ( 2 mi) ENE of Meeker, OK
MAP 3.4 2011/11/06 09:22:04 35.585 -96.823 5.0 3 km ( 2 mi) S of Sparks, OK
MAP 2.7 2011/11/06 08:14:12 35.474 -96.794 5.0 7 km ( 4 mi) NNE of Johnson, OK
MAP 3.2 2011/11/06 07:32:40 35.544 -96.901 4.9 5 km ( 3 mi) N of Meeker, OK
MAP 3.8 2011/11/06 06:31:10 35.559 -96.874 5.0 7 km ( 4 mi) NNE of Meeker, OK
MAP 3.0 2011/11/06 04:54:00 35.540 -96.687 5.0 6 km ( 4 mi) N of Prague, OK
MAP 3.6 2011/11/06 04:03:41 35.554 -96.760 5.0 8 km ( 5 mi) SE of Sparks, OK
MAP 5.6 2011/11/06 03:53:10 35.537 -96.747 5.0 8 km ( 5 mi) NW of Prague, OK
MAP 3.6 2011/11/05 14:36:30 35.584 -96.789 4.9 4 km ( 2 mi) SE of Sparks, OK
MAP 3.4 2011/11/05 13:42:26 35.530 -96.766 5.0 9 km ( 5 mi) NW of Prague, OK
MAP 3.3 2011/11/05 11:24:15 35.521 -96.778 5.0 9 km ( 6 mi) WNW of Prague, OK
MAP 3.3 2011/11/05 09:12:11 35.591 -96.788 4.9 4 km ( 2 mi) SE of Sparks, OK
MAP 2.7 2011/11/05 07:50:42 35.559 -96.762 4.8 8 km ( 5 mi) SE of Sparks, OK
MAP 2.7 2011/11/05 07:44:34 35.488 -96.755 5.0 6 km ( 4 mi) W of Prague, OK
MAP 3.4 2011/11/05 07:27:20 35.566 -96.698 5.0 9 km ( 6 mi) N of Prague, OK
MAP 4.7 2011/11/05 07:12:45 35.553 -96.748 4.0 9 km ( 6 mi) SE of Sparks, OK

Back to Map Centered at 36°N, 96°W (That’s Tulsa, roughly)

 

23 quakes in two days.  Oklahomans might be excused for wondering what’s up.

Just technical details here.  USGS issued a notice on both of the larger quakes, the 4.7 on Saturday, November 5, and the 5.6 on Sunday, November 6.

Still, this isn’t much of a swarm for an active quake zone, like California, or Yellowstone, or Alaska.

But, for Oklahoma, this is big.  Plus, it appears to lay observers that earthquake intensity and frequency both have been building for over a year.   Recent earthquakes in Arkansas and Texas concern some local residents who fear the quakes are the result of hydrofracturing (fracking) activities being conducted in relation to natural gas and oil drilling and extraction.

And as this map of U.S. quakes in the preceding week shows, the quakes in Oklahoma are the largest in the U.S. for the week.

USGS animation of quakes in US for week ending Nov 6, 2011, afternoon

More quakes in California, on the USGS maps -- but the Oklahoma quakes are biggest

Research continues, and local residents stay nervous.

Here’s a map that should update with new quake information — which means, Oklahomans hope, that the indicators of quakes will go away over the next few days.

USGS map of Oklahoma City/Tulsa area where earthquakes occurred in the week leading up to November 6, 2011

USGS map of Oklahoma City/Tulsa area where earthquakes occurred in the week leading up to November 6, 2011

 


Laden’s late; but, is Yellowstone gonna blow AND TAKE US WITH IT?

February 26, 2011

The veteran reader of this blog — can there be more than one? — may recall the kerfuffle a couple of years ago when there was a “swarm” of earthquakes in the Yellowstone.  Alas for those prone to panic attacks, the swarm ran through the Hanukkah/Ramadan/Christmas/KWANZAA/New Year’s holidays, when other news is slack.

Yellowstone Caldera, Smith and Siegel 2000

What the Yellowstone Caldera might look like from space, by moonlight, on a clear night, if you can imagine the borders of Yellowstone National Park very vividly - Smith and Siegel, 2000

You might understand, then, why I say Greg Laden turns his considerable story-telling prowess to the issue late.  Still, his prowess towers over the rest of us, and he tells a great story.

Is the Yellowstone safe? he asks, rhetorically.

The answer is complex:

1) Wear a seat belt when driving around in the region;

2) Don’t feed the bears and make sure you understand bear safety; and

3) Somebody is going to get blasted by some kind of volcano in the area some day, but even if you live there the chances are it won’t be you.

The joy is in the journey — go read Laden’s explanation of the rising lava.  Heck, even those of us who think we know that stuff understand it better when he explains it.

Earlier in the Bathtub:

Also see:


Mexico earthquake: What do we know?

April 5, 2010

Baja California — that’s in Mexico, you European readers — got hit with a large earthquake tonight, a 7.2 on the logarithmic Richter Scale according to some early reports. At least one person died; Mexicali, on the border with California, reports many people trapped.  A state of emergency has been declared.

BBC gives the facts:

A 7.2 magnitude earthquake has hit the Mexican peninsula of Baja California, killing at least one person and causing tremors as far away as Nevada.

The quake struck at 1540 (2240 GMT), 26km (16 miles) south-west of Guadalupe Victoria in Baja California, at a depth of 32km, said the US Geological Survey.

Some people are still trapped in their homes in the city of Mexicali, where a state of emergency has been declared.

It was the worst quake to hit the region for many years, officials said.

The US Geological Survey said some 20 million people felt tremors from the largest quake to hit the area since 1992.

My students with Mexico connections tend to come from farther east, and higher in the mountains — I don’t think I have a single student who visits Baja California on breaks.  But the news will prompt questions from them tomorrow.

The U.S. Geological Survey (USGS) tracks earthquakes around the world.  It should have solid information.  Data on the April 4 7.2 quake are here.

Here’s the tectonic summary:

A magnitude 7.2 earthquake occurred at 3:40:40 p.m. (local time at the epicenter) on Sunday, 4 April 2010 in Baja California, approximately 75 km south of the Mexico-USA border. The earthquake occurred at shallow depth (approximately 10 km) along the boundary zone between the North American and Pacific plates. Since earthquakes have been recorded instrumentally, only two similar sized earthquakes have been recorded in the area. The first was the 1892 earthquake estimated at magnitude 7.0-7.2 along the Laguna Salada fault just south of the USA-Mexico border. The second was the 1940 Imperial Valley magnitude 6.9 earthquake which occurred in southernmost California. Today’s event is located nearly in line with these earthquakes along the plate boundary, but is situated farther to the south. There are several active faults in the vicinity of today’s earthquake, and the particular fault that generated this quake has not yet been determined. Faulting is complex in this region, because the plate boundary is transitional between the ridge-transform system in the Gulf of California and the continental transform system in the Salton Trough. Most of the major active faults are right-lateral strike-slip faults with a northwest-southeast orientation, similar in style to the San Andreas fault to the north. Other faults in the vicinity with the same orientation include the Cerro Prieto fault and the Laguna Salada fault.

USGS hosts good maps, too, like this “shake map” (click the map to go to the USGS site for more information):

USGS "shake map" for the April 4 7.2 quake near Mexicali, Mexico

USGS "shake map" for the April 4 7.2 quake near Mexicali, Mexico - Click to go to USGS site

What other questions can we anticipate?  Somebody will ask whether this quake is related to the Haiti and Chilean quakes (probably not closely related).  Somebody will wonder about the Pacific Ring of Fire, and this quake’s relation to volcanoes and general earthquake activity around the Pacific (high relationship).  Someone will want to know about quakes in your area.  Is this the precursor to “the Big One?”

The USGS site is a good place to start on all of those questions.


Okalahoma earthquakes: No swarm

March 6, 2010

Three earthquakes in a week do not make a swarm.  Interesting that the last post on an earthquake in Oklahoma drew earthquake conspiratorialists and “skeptics.”  Too many people distrust all science and sources of information these days.

Here’s the dirt on Oklahoma’s shaking in the last week, from the U.S. Geological Service site:

Earthquake List for Map Centered at 36°N, 97°W

Update time = Sat Mar 6 18:00:02 UTC 2010

Here are the earthquakes in the Map Centered at 36°N, 97°W area, most recent at the top.
(Some early events may be obscured by later ones.)
Click on the underlined portion of an earthquake record in the list below for more information.

MAG UTC DATE-TIME
y/m/d h:m:s
LAT
deg
LON
deg
DEPTH
km
LOCATION
MAP 3.1 2010/03/05 20:35:13 35.608 -96.783 5.0 3 km ( 2 mi) E of Sparks, OK
MAP 2.5 2010/03/03 04:35:17 35.549 -97.282 5.0 2 km ( 1 mi) SSE of Jones, OK
MAP 4.1 2010/02/27 22:22:27 35.557 -96.747 3.3 9 km ( 5 mi) SE of Sparks, OK

This isn’t unusual at all, of course. I think many people just don’t understand that earthquakes happen all the time, but they usually get crowded out of the newspaper because no one really cares.

For contrast, take a look at this animated map of a strip a little wider than Utah, covering from north of the Yellowstone Caldera to Arizona.  Run the animation.  Generally on any day there will have been at least two dozen earthquakes in the previous week, several magnitude 3, occasionally a magnitude 4 thrown in.

Almost none of those quakes make any news.

Maybe it’s the Earth, laughing.  We can hope.

Laugh, and the world laughs with you;
Weep, and you weep alone.
For the sad old earth must borrow it’s mirth,
But has trouble enough of its own.
Sing, and the hills will answer;
Sigh, it is lost on the air.
The echoes bound to a joyful sound,
But shrink from voicing care.

(Excerpted from “Solitude,” 1917, by Ella Wheeler Wilcox (1850-1919))


Shakiest states — geologically, that is

March 4, 2010

USGS map of states with the most quakes

Quake rankings of states

Which states shake the most?  Here are the top 20.

Surprised that Maine makes the list?

Much more from the US Geological Survey here, “Top Earthquake States.”


Oklahoma earthquake

March 1, 2010

While attention was on Hawaii, wondering about the tsunami’s effects there, Oklahoma got hit with an earthquake of magnitude 4.1, a big one for such a flat, geologically inactive state (link goes to USGS site).

Epicenter of Oklahoma earthquake, February 27, 2010

Epicenter of Oklahoma earthquake, February 27, 2010

Most likely there is no connection between the Oklahoma quake and any other shaking on Earth in the past week or so.


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