You are browsing the archive for earthquake Archives - Page 2 of 3 - Mountain Beltway.
7 September 2011
Another updated aftershock plot…
A up-to-date tally of the aftershocks from the Mineral, Virginia earthquake is presented as a time vs. magnitude plot.
30 August 2011
Updated aftershock plot
The USGS reports more aftershocks, so your humble graphing servant has responded with a plot that updates the images I showed you last week. Here you go: Embiggable, via a simple click. Again, the “decay” pattern jumps out at us. One thing that I’m also noticing is how there are no events below 2.0 magnitude. What’s up with that? Simply not detectable? …or not worth bothering with? By the way, …
28 August 2011
Damage to the Ecuadorian Embassy
My wife Lily is an Ecuadorian citizen. She was born in Quito, and we have traveled there together. (She’s also a U.S. citizen.) After the big earthquake on Tuesday, significant structural damage was reported at several Washington landmarks including the Washington Monument and the Smithsonian Castle. Another one, less recognizable to most folks, but key in our personal geography, is the Embassy of Ecuador. Not only is it an outpost …
27 August 2011
Animated GIF of Virginia quake aftershocks
So last Tuesday we had an earthquake, and we expected some aftershocks as the crust in the Mineral, Virginia, area adjusted to the new stress regime. We expected those aftershocks to be lesser in magnitude, and to take place after the main shock. In other words, we would predict the following: And, indeed, over the past several days, that’s actually what happened:
25 August 2011
Aftershocks
Since Tuesday’s big earthquake, we’ve had 5* aftershocks in the same area (and possibly on the same fault). The most recent one popped off last night at 1am. Here’s a plot showing the size of the events (moment magnitude) relative to the passing of time: Note that the quakes that came after “the big one” are smaller in their size (the amount of energy that they release into the surrounding …
24 August 2011
Cracking up
Callan shares a geological analogue that developed in his house yesterday: en echelon tension fractures, common in sheared rocks, appeared on his ceiling due to the Mineral, Virginia earthquake.
23 August 2011
The Mineral, VA earthquake of August 23, 2011 – UPDATED
Callan describes his experience with the widely-felt east coast earthquake of August 23, and provides an analysis of the fault(s) that may be reponsible.
15 March 2011
New GPS vectors
Just wanted to call your attention to two new maps showing GPS displacement vectors from Japan. (Barry left links to these images in a comment yesterday.) These images are hosted on the website of the Geospatial Information Authority of Japan, and though I can’t read the Japanese to verify their authorship, I presume that agency produced them as well. They are easier to read than the one I posted on …
12 March 2011
Secondary effects
Earthquakes themselves are rarely directly responsible for deaths… If you’re out in a field, or a park, it’s a disorienting experience, and you may see some weird stuff, but you’re not likely to be killed via whiplash. Usually, casualties are induced due to the collapse of buildings, or roads, bridges, tunnels, or other infrastructure failing due to being shaken by the seismic waves. Someone paraphrased the NRA yesterday with the …
The morning after
A new resource for the Japanese earthquake is online this morning, a “supersite” similar to the ones that exist for other huge events. Checking it out this morning, I found some interesting stuff. Over night, there have been more aftershocks, and here’s the most recent 600 or so events in the area, taken from IRIS’s interactive map. You can see the big circle that represents yesterday’s main shock: Explore the …
Callan Bentley is Associate Professor of Geology at Piedmont Virginia Community College in Charlottesville, Virginia. He is a Fellow of the Geological Society of America. For his work on this blog, the National Association of Geoscience Teachers recognized him with the James Shea Award. He has also won the Outstanding Faculty Award from the State Council on Higher Education in Virginia, and the Biggs Award for Excellence in Geoscience Teaching from the Geoscience Education Division of the Geological Society of America. In previous years, Callan served as a contributing editor at EARTH magazine, President of the Geological Society of Washington and President the Geo2YC division of NAGT.