Three new videos from Montana
I spent several enjoyable weeks in Montana last month, and shot some new video content there for my YouTube channel. Here are three videos that may be of interest to readers of this blog:
earthquake
Earthquake Storms, by John Dvorak
I’ve come to the end of my run of reading John Dvorak’s geology books. This is the fourth one for me to consume, but it was apparently the first he wrote. The topic is earthquakes, specifically those that occur along the San Andreas Fault in California. I’ve read a fair bit, it feels like, about … Read more
Friday fold: Taiwanese metasediments
This Friday, in search of a Friday fold, we head to Taiwan, not far from the epicenter of this week’s destructive earthquake(s).
Big earthquake in southwestern Mexico, M8.1
The M8.1 southwestern Mexico earthquake is discussed and placed in context.
An opportunity to help in Canoa
As I mentioned last week, I have family in one of the coastal towns in Ecuador that was hardest hit by the magnitude 7.8 earthquake the previous weekend. Don and Wendy have asked me to share this opportunity to help: The James Dean Byrd Foundation runs a school in Canoa, La Escuela Bilingue los Algarrobos, … Read more
Firsthand reports from Canoa, Ecuador after the quake
Callan’s mother-in-law lives in one of the most strongly-shaken regions of Ecuador. Here, she and her boyfriend recount the experience of the earthquake Saturday night and its aftermath. Includes 8 photos from the scene.
Fractures on a seismic sign
On the campus of the University of Texas at El Paso, there is a sign for the Kidd Seismic Observatory. The sign has seen some brittle deformation of its reflective letters. I infer this due be due to differential shrinkage of the letters (relative to the sign they are attached to) in the intense Texas … Read more
Salt dough physiographic province map of Virginia
By local prodigy Hannah Holland, elementary school student: Click through to make it bigger and see some details. Nice work, Hannah! Very impressive, and thanks for sharing!
More earthquake damage
These are all in the northern stairwell between the 2nd and 3rd floors of the Godwin Building here on the Annandale campus of NOVA. The cement blocks have clearly separated along their mortared edges, and the disruption of the paint layer in a series of en echelon fractures reveals that deeper structural issue. I find … Read more
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.
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. … Read more
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 … Read more
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 … Read more
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” … Read more
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.
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.
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 … Read more
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 … Read more
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 … Read more