Guest Video: Cascades Volcanoes

We have looked at some of these volcanoes before, but this video presents an in-depth look at the situation in the Pacific Northwest, as seen in the 1990s.

Updates/More information:

A 2015 study on Mount Unzen and its effects on the Shimabara Peninsula.

CENAPRED’s monitoring page for Popo. (Spanish) Yes, the “smoking mountain” is still doing its thing today. Webcams de Mexico also has a good Popocatepétl page. (Spanish)

Pierce County’s Mount Rainier page.

Some volcano observatories:

Featured image: NASA

Kick-’em-Jenny Volcano on Orange Alert

Update, March 15: UWI seismic experts note that the number of quakes at the volcano is dropping. However, Kick-‘Em-Jenny has done that before and then gone on to an eruption, so they are keeping the level at orange for now.

No, seriously, that’s the name of this underwater Caribbean volcano. Here’s a post I did on it at the Clear Sight blog in 2015.

The University of the West Indies Seismic Research Centre has raised the alert level to orange again and has set up an exclusion zone. More details are available in this UPI story.

Per the Kick-’em-Jenny Global Volcanism Program page, the exact details of the current increase in activity are unspecified. A combined British/UWISRC research team recently studied the volcano.

Featured image: Lyn Topinka, USGS, via Wikimedia.

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.

Guest Video: Quicksand

I have never wandered into this nasty stuff but had always thought you can “swim” your way out of it.

Apparently it’s not that simple.

Note that they’re doing this while the tide is out. What if it were coming back in and he was all alone?

Scary thought. So is the fact that this quicksand looks exactly like the solid mud.

Bottom line: ALWAYS pay attention to your surroundings, and if you see warning signs, heed them.

On a reassuring note, reportedly wet quicksand isn’t a bottomless pit. So you might not not sink in all the way.

Per Wikipedia, density differences are a factor, too.

Featured image: Urban Dispute, CC BY-ND 2.0.

Guest Videos: Capetown – The First Modern City to Go Dry?

It seems strange to see all that water splashing around the city, unused. But desalination isn’t easy or cheap:

Nevertheless, the Canary Islands reportedly depend on desalination to keep their economy as well as their daily lives going.

Could this work for Capetown, too?

Featured image by Vincentvanoosten at Pixabay. Public domain.

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,

La Palma Eruption Unlikely Any Time Soon

Just saw in the online news that there is concern about increased seismicity at La Palma volcano in the Canary Islands.

According to experts who reportedly met Friday, magma did move inside the volcano, but it was a relatively small amount and very deep–almost 20 miles below the surface.

Of course they are monitoring this closely, but no warnings have been issued yet.

Featured image: NASA

East Coast Tsunamis

On February 6 this year, the US National Weather Service broadcast its routine monthly tsunami test alert. Something went wrong, and two private weather companies notified subscribers it was a real tsunami.

Hurray for routine test alerts! Mistakes can highlight errors and get them fixed. This one didn’t happen during an actual disaster and will probably result in more accurate tsunami real-time information for residents of eastern North America.

They need it.

While the Atlantic coast is a passive margin, unlike the western coast (where tectonic plates are colliding), tsunamis do happen there.

They even occur far from the coast!

All you need to make a tsunami is to displace a sizable amount of water. One quiet Sunday morning in April 1908, for example, an estimated 42.6 million cubic feet of land (1.2 million m3) slid into Quebec’s Lièvre River, causing a 50-foot (15-meter) wave on the opposite bank that killed 33 people.

Probably the most famous eastern North American tsunami came from the enormous 1929 underwater landslide that either caused or was triggered by a surprise M7.2 earthquake on the Grand Banks.

Almost 30 people died in Newfoundland and Nova Scotia in that disaster.

It’s interesting that one of the eyewitnesses in that video saw the approaching wave.

According to one study, the quake was felt in Newfoundland around 5 p.m. local time, and the waves arrived between 7:30 and 8 p.m., when it was dark.

The witness is convinced he saw that. It just might have been another tsunami. His description reminds me of aerial views I’ve seen on the news.

Such an error is very common and very understandable.

While I have never been in such a horrible disaster, I did witness a car plowing into a group of people at a bus stop, many years ago, and from my own recall of the event I know there can be problems with eyewitness accounts.

Your mind works differently in an emergency.

So remember this as you explore an interactive hazard map from NOAA for historical tsunamis.

The most reliable information comes from instruments, for example, measurements of maximum wave height (not much) from Woods Hole and Nantucket on June 13, 2013.

Nevertheless, the sheer volume of witnessed tsunami reports on this map, going back to the 19th century, shows that Atlantic Ocean tsunamis are a thing. They aren’t usually as dramatic as those in the west, but tsunamis did kill at least 60 easterners during the 20th century.

Featured image: The 1929 Grand Banks earthquake epicenter, NASA

Guest Videos: Where and How Big Is The Earthquake?

Have you ever wondered how seismologists locate earthquakes and figure out their magnitude?

Here is a video about it from New Zealand’s GNS Science:

They changed over from the Richter scale to moment magnitude because there are other factors involved, including physical qualities of the rock that breaks in a quake and – spaghetti?

Of course, the bottom line is what controls the shaking you’re going to feel at any given location.

Here is more information about the USGS Shakemap. Outside the US, check with your local, regional, and/or national geoscience institutions for more information.

Featured image: Damage from a 1976 Guatemala earthquake, by USGS, via Wikimedia.