Mount Spurr might be rumbling to life (near Anchorage)

[Mark Sedenquist]

To start out today, wanted to show the level of earthquake activity around Mount Spurr. Not big quakes, and most of these have occurred over the last four days. But something seems to be going on.


November 4th at 7:20 am (Courtesy of AVO)

The shaded blue area (with the little blue dots) represents glacier ice -- which could heat up in an eruption.

Note: I will be traveling the next couple of days, and there not as able to check in the monitoring sites.

Mark

[Mark Sedenquist]

Activity has slowed a great deal over the last week.

Here is the AVO update:

November 16, 2024, 10:40 am

Unrest continues at Mount Spurr. Small, shallow earthquakes underneath the summit region continue at a low rate.

I will keep monitoring, but probably there won't be any more daily updates unless the volcano gets more active again.

Mark

[Mark Sedenquist]

An interesting thing happened yesterday -- I didn't know such things were possible.

From the ALASKA VOLCANO OBSERVATORY

KATMAI (VNUM #312170)
58°16'44" N 154°57'12" W, Summit Elevation 6716 ft (2047 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Strong northwesterly winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes have picked up loose volcanic ash erupted during the 1912 Novarupta-Katmai eruption and are carrying it to the southeast. The National Weather Service has issued a SIGMET for this low-level event and suggests that the maximum cloud height is 6,000 ft (1.8 km) above sea level.

This phenomenon is not the result of recent volcanic activity and occurs during times of high winds and dry snow-free conditions in the Katmai area and other young volcanic areas of Alaska. No eruption is in progress. All of the volcanoes of the Katmai area (Griggs, Katmai, Novarupta, Mageik, Martin, Snowy and Trident) remain at Aviation Color Code GREEN and Alert Level NORMAL. Resuspended volcanic ash should be considered hazardous and could be damaging to aircraft and health.

Can you imagine that? This ash layer has been loose and able to cause issues since 1912!

[AZBuck]

'Significant' is a relative term. The presence of volcanic ash in the atmosphere automatically triggers a SIGMET (Significant Meteorological Information) for aircraft. Ash below 6,000' in such a remote location should not be an issue for commercial aircraft. Even small piston engine planes have no problem getting above that altitude, This should also not present any problems for autos with a decent air filter.

Recent minor earthquakes or even strong winds in the area might have loosened a surface layer of ash that had not completely fused into a cohesive solid, most likely because it wasn't hot enough for long enough.

AZBuck

[Mark Sedenquist]

OK. I see your point. I would have thought it would have been buried under glacier ice by now.

Another picture-perfect day up there:

4:11 pm PST -- November 18th -- Courtesy of AVO.

Mark

[Mark Sedenquist]

I have never seen the wind sock "relaxed" here. Pretty undesirable conditions, I would think.

But, this actually looks like some blue sky today!


November 23rd, Noon. PST Courtesy of AVO.

[Mark Sedenquist]

Looks to me like activity is increasing in the region!


Courtesy of AVO. Screen capture December 6th at 6:30- am

[Mark Sedenquist]

A couple more slightly larger earthquakes. The tan color are 2.0 or larger.


Courtesy of AVO -- December 11th at 11:30 am

[Mark Sedenquist]

Update as of December 30th


Courtesy of AVO -- December 30th at 08:30 am

December 29, 2024, 10:46 am

Shallow earthquake activity near the summit of Mount Spurr continues at an elevated rate, but lower than yesterday. Variation in the numbers of earthquakes is common during periods of unrest at volcanoes. Web camera images from yesterday showed minor steaming near the summit, but this is not unusual. Satellite images from the past day showed no signs of other activity at the surface.

Seems like more activity than I have seen on the monitors over the last week. But if you look at the previous image from December 11th -- not much of a significant increase this month.

[Mark Sedenquist]

Looks like more shaking to me!


January 3rd at 10:30 am

January 3, 2025, 12:12 pm

Unrest persists at Mount Spurr, with ongoing shallow earthquake activity and surface deformation.

Although data processing continues, our current estimate is that over 260 earthquakes were located at Mount Spurr this past week. Most (more than 90%) were very small, with magnitudes less than 1. Three earthquakes had magnitudes larger than 2, with the largest being a M2.9 from January 2. Many of the earthquakes occurred in clusters on December 28 and January 2. Most of the events continue to be shallow and located under Mount Spurr's summit region. The kind of waxing and waning we saw this week is not uncommon for volcanic earthquake swarms.

The local network of GNSS (GPS) stations continues to record slow but steady ground movement upward and outward, which has been ongoing since March 2024. This is consistent with a pressure increase between 2 to 3 miles (3 to 5 km) depth about 2 to 2.5 miles (3-4 km) west of the summit, which is the general area of ongoing earthquake activity.

January 2, 2025, 12:46 pm

Shallow earthquakes beneath the summit of Mount Spurr continue, at an increased rate today compared to the past few days. A flurry of earthquakes this morning included one with a magnitude of 2.9 at 5:39 AKST (14:39 UTC), which is among the largest seen in the current episode of unrest. Earthquake activity has quieted again over the last couple of hours. While notable, variation in the number and size of earthquakes is common during periods of unrest at volcanoes and at this time does not suggest that eruptive activity is more likely in the near future. Clear satellite and webcam images from the past day showed no unusual surface activity.