Guest Videos: Taking A Volcano’s Pulse


If you have been following the Popocatepetl updates, you’ll know that I’ve been paying attention to the webicorder recently.

It’s fun to be able to see the volcano’s activity even when weather has it shrouded in clouds.

What is a webicorder?




What do earthquakes have to do with volcanoes?

A better question is, what can earthquakes (and webicorders) tell volcanologists about the events deep inside a fire mountain?




Popocatepetl, of course, is not a long-dormant volcano–its present activity began in 1994! I have no idea what I am looking at on the PPIG webicorder, but it’s fun to try to figure out.

The Alaska Volcano Observatory starts you out with lots of information on how to read a webicorder and also has live links to webicorders on Alaskan volcanoes.

And if you want even more information, check out the USGS seismogram display page! (Note: This includes non-volcano-monitoring seismometers, too.)



Featured image: Mammoth Mountain (left) by Geographer via Wikimedia, CC BY 1.0. Long Valley Caldera MEM webicorder (right; I don’t know if this relates to Mammoth Mountain), California Volcano Observatory


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Guest Video: The Salton Sea


A study at the end of June made headlines about earthquake hazard on the San Andreas Fault. The research looked at the area covered by the Salton Sea:



According to news reports, geologists found:

. . . a nearly 15.5-mile-long, sheared zone with two, nearly parallel master faults and hundreds of smaller, rung-like cross faults. . . The discovery . . . reveals the southern tip of the San Andreas Fault changes fairly gradually into the ladder-like Brawley Seismic zone. The structure trends northwest, extending from the well-known main trace of the San Andreas Fault along the Salton Sea’s northeastern shore, to the newly identified East Shoreline Fault Zone on the San Andreas’ opposite edge.

. . .

Future earthquakes in that zone or near the San Andreas Fault could potentially trigger a cascade of earthquakes leading to the overdue major quake scientists expect along the southern San Andreas fault zone . . .

So, perhaps it’s good that the “Riviera” scheme never worked out.

While seismologists scramble over the area to learn more about earthquake hazards, the USGS is monitoring the local volcano situation–which includes five vents discovered in 2013–through the California Volcano Observatory.

Again, not a good place for a resort!


Featured image: 12019, at Pixabay. Public domain.


Guest Video: The Secret Lives of “Quiet” Volcanoes


It’s difficult to monitor an underwater volcano like Kick-’em-Jenny and it’s also dangerous when that volcano is restless. This is why scientists use volcanic earthquakes to take the fire mountain’s “pulse” from a relatively safe distance.

Have you ever wondered how volcanologists do that? Here is a whole hour-plus 2013 webinar from IRIS Earthquake Science about it, nerdy but aimed at nonspecialists like us.

As we will see with this weekend’s Sunday Morning Volcano post, there are a lot of quiet but still active volcanoes in the Eastern Caribbean. Fortunately, these sleeping trouble-makers are bedecked with seismometers and other monitoring equipment so that volcanologists can give the local residents as much advance warning as possible when the volcano starts to wake up.


    Featured image: Harmonic tremor at Mount St. Helens in March 1980. Source.


Guest Videos: Finding Megaquakes Before They Happen


On March 8, a two-month seafloor-drilling expedition set off to investigate the underwater megathrust fault that most threatens New Zealand’s North Island–the Hikurangi subduction zone.

The South Island is also at risk from its own big fault zone:

Information obtained from these investigations will help geoscientists all over the world improve their understanding of subduction zones and the deadly megathrust earthquakes they spawn.

Sometimes it is also possible to get 3D studies of a subduction zone.

The Hikurangi zone researchers also want data that will help them understand slow-slip quakes and their relationship to the damaging “fast” earthquakes that we’re all familiar with.


Featured image: US Air Force/Technical Sergeant Daniel St. Pierre. http://www.march.afrc.af.mil/News/Photos/igphoto/2000266910/


YVO on Yellowstone Earthquake Swarm


YVO stands for Yellowstone Volcano Observatory. Check their website whenever you see scary headlines about Yellowstone Volcano.

Earthquake swarms do happen there, and the top experts addressed the present one with a lengthy post yesterday, describing it in plain English. Here’s an excerpt:

While it may seem worrisome, the current seismicity is relatively weak and actually represents an opportunity to learn more about Yellowstone. It is during periods of change when scientists can develop, test, and refine their models of how the Yellowstone volcanic system works. Past seismic swarms like those of 2004, 2009, and 2010, have led to new insights into the behavior of the caldera system. We hope to expand this knowledge through future analyses of the 2017 and 2018 seismicity.

The earthquakes, too, serve as a reminder of an underappreciated hazard at Yellowstone—that of strong earthquakes, which are the most likely event to cause damage in the region on the timescales of human lives…


Featured image: 12019,


Guest Video: Preparedness Now, The Great California Shakeout

 
We took part in the Great ShakeOut here in Oregon this week. I didn’t do too well, so it was a terrific wake-up call. However, I was disappointed by the reaction of many people.

While scheduling some guest videos for you, in the unlikely event that my writing projects tie me up for part of next week, I came across this one, “Preparedness Now, The Great California ShakeOut.” It’s good enough to share today.

Remember, when the ground starts moving, duck, cover, and hold on! And as I learned this week, just thinking through your disaster plan doesn’t work too well – do a walk-through.