Eruptions Newsletter #2 for March 14, 2024

Activity News

Spurr, Alaska

For folks living in Anchorage, the increasing unrest at Alaska’s Mount Spurr must be unsettling. The last eruption from the Aleutian volcano was back in 1992, but it was a doozy … well, a doozy for an eruption near a major US city over the past few centuries (sorry, that’s a lot of qualifiers). The VEI 4 eruption 23 years ago was itself the first eruption at Spurr since another VEI 4 eruption in 1953. Admittedly, this is only two eruptions, but Spurr does have the potential for explosive blasts.

However, we’re not there yet. The Alaska Volcano Observatory issued a new information statement on Spurr on March 12 detailing the sharp increase in sulfur dioxide emissions from 50 metric tons/day in December 2024 to 450 metric tons/day in March 2025. Now, the only way you get that much more sulfur being emitted is from new magma rising into the magmatic system under the volcano. As it rises, it releases gases like sulfur dioxide, water vapor and carbon dioxide. A 9-fold increase like that means more new magma in the system.

There have been hundreds of earthquakes under Mount Spurr over the past week and have increased sharply since the start of 2025 (see below). They have mostly been relatively close to the surface (<2.5 miles / 4 kilometers down) and small … again, hinting at magma moving up into the main part of the volcano. Overflights of Spurr since February have shown a lot more steam vents (fumaroles) in the summit and crater area of the volcano as well. You can see some in the AVO image above.

All this unrest means that AVO now thinks an eruption is “likely within weeks to months”. This doesn’t mean an eruption will happen in that time span, just like a 75% chance of rain doesn’t mean you’ll get wet. However, the chances are pretty good that you will, so carry an umbrella. For a volcano, this means being prepared in Alaska for ash fall. Precautions like masks to protect yourself from breathing in the volcanic shards (remember, volcanic ash is glass!) and being prepared for potential disruptions in air traffic across the Northern Pacific.

The 1989 eruption of nearby Redoubt was made famous for the near-disaster of KLM Flight 867 that flew through the ash plume from the activity. This event helped create the Alaska Volcano Observatory. The 1992 eruption at Spurr (above) was the first real test of AVO and its ash warnings. These days, AVO, the National Weather Service and the Volcanic Ash Advisory Centers all give airlines this vital information in near-real time. Hopefully with all the turmoil in the federal government, especially in the realm of science, we’ll be ready to face the spectre of an explosive eruption so close to Anchorage and within such a busy flight corridor.

Fuego, Guatemala

One volcano that erupts with much higher frequency than Spurr is Guatemala’s Fuego. However, it had taken a brief respite over the past few weeks, the volcano roared back to life with some spectacular lava fountains. Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología (INSIVUMEH), the volcano monitoring agency for the country, reported fountains reaching 300 meters (~984 feet) … which, as the nighttime webcam images show, was mighty impressive. That is roughly the same as the 78-floor-tall 4 World Trade Center building in New York.

Fountains like these at Fuego are usually driven by magma that is chock full of dissolved gases. The pressure from the bubbles forming don’t produce an explosion because the magma is basaltic, so lower viscosity than we find at places like Spurr. Intense, the bubbles help “spray” the lava out of the volcano at high pressure, a bit like a hose.

The products of lava fountains like these are volcanic ash and bombs. You can see the bombs as the glowing blobs in the image below. They might be centimeters to meters in size, but they are still red hot as they fly (and sometimes when they land). The bombs and debris (tephra) can create scoria flows of hot rubble — you can see that on the slopes below the summit.

This new activity did prompt some evacuations of people who live near Fuego. The volcano is less than 50 kilometers (~33 miles) from the capitol of Guatemala, putting over 1,000,000 people within that distance of the volcano.

Kīlauea, Hawai’i

I wanted to give a brief nod to Kīlauea’s 13th eruptive episode that happened this week. The lava fountain during this eruption was not as tall as the fountain at Fuego, “only” reaching ~100-130 meters (325-425 feet), but they were still spectacular in its own right (see below).

Volcano Research

None this week … there will be soon.

Odds & Ends

When reporting on geologic events, I think that being accurate is good, right? Yet, sometimes when it comes to something as simple as describing an event that happened (like an earthquake), the media can miss that mark by a lot … and in multiple ways. For example, check out this headline from earlier this week:

So, what’s wrong with this? True, there was a tsunami “update” for the Eastern US seaboard. However, it was because of a M6.6 earthquake at Jan Mayen in the north Atlantic Ocean. This island is on the Mid-Atlantic Ridge and a full ~500 kilometers (300 miles) to the east of Greenland. And yes, it is a “volcano island” in the sense that there is a potentially active volcano on Jan Mayen that last erupted in 1985, but is located along a plate boundary between North America and Eurasia, so earthquakes can happen unrelated to its volcanic nature.

If you did happen to click the Newsweek link, you would have been greeted by this video still:

…which has nothing to do with the earthquake at all. It is instead a report on a tsunami warning that happened months ago for the west coast of the US after a M7.0 there. Oh yes, and the “tsunami update” in the headline here refers to the fact that there wouldn’t be a tsunami.

The two sources of information for this Newsweek article are the US National Tsunami Warning Center (good!) and … an X account called “Volcaholic” (bad!) In situations like this, your sources should be reliable, verified government or scientific agencies, not random disaster news aggregators, no matter how quotable or excitable they are. This is why we can’t have nice things.

Sounds of the Week

I’ve served up a lot of songs that are relative aggressive lately. So, to mix it up, I offer you my favorite song about fountains in honor of the impressive eruptions at Fuego and Kīlauea this week. It’s “Virginia Reel Around the Fountain” by the Halo Benders. Now, many of you might be familiar with the Built to Spill version of this song included in their excellent Live album, but it started like as a Halo Benders song. And yes, you’re not wrong to say that the background singer sure sounds like Doug Martsch of Built to Spill, because it is. That’s because the Halo Benders were a Built to Spill side project with K Records founder Calvin Johnson. Now, Calvin’s caterwauling is an acquired taste, but this song is a stone cold indie banger.

Questions? Comments? Thoughts? Feel free to send me a note or follow me on Bluesky (@erikklemetti.bsky.social).