Various sources are attempting to read impending doom and disaster into the recent seismic activity at Yellowstone. If you check the USGS list of quakes in that area, you will see that they are gradually decreasing, not increasing.
None of the quakes are harmonic in nature – just regular run of the mill earthquakes.
“…The earthquakes are just normal earthquakes so far – none of the dreaded/anticipated harmonic tremor that might indicate an eruption. This will likely mean that more gas and water monitoring will be occurring in the park in the coming weeks/months….”
That hasn’t stopped ill-informed sources like the Times of London from doing a doom and gloom story. (Let’s face it, George W. Bush is to blame).
What you probably aren’t seeing is the information that a similar swarm like this occurred in the 1980’s.
“….He plays down the swarm, noting that things like this happened in the 1980s and that Yellowstone has seen over 80 eruptions in the caldera since the last “supervolcano” eruption 640,000 years ago. I know Dr. Lowenstern pretty well, and even at AGU when I talked to him (before the swarm), he seemed to play down the huffing and puffing the caldera experiences on a yearly basis. It would take much more activity to get the YVO folks concerned about a potential new eruptive period….”
On Jan 2 the USGS released this statement:
“…Yellowstone Lake Earthquake Swarm Update: 2 January 2008
The University of Utah Seismograph Stations reports that as of 1800 MST on 2 January 2009, seismicity of the ongoing Yellowstone earthquake swarm continues. Over 500 earthquakes, as large as M 3.9, have been recorded by an automated earthquake system since the inception of this unusual earthquake sequence that began Dec. 27, 2008. More than 300 of these events have been reviewed and evaluated by seismic analysts. Depths of the earthquakes range from ~ 1km to around 10 km. We note that the earthquakes extend northward from central Yellowstone Lake for ~10 km toward the Fishing Bridge area, with a migration of recent earthquakes toward the north. Some of the dozen M3+ earthquakes were felt in the Lake, Grant Village and Old Faithful areas. Personnel of the Yellowstone Volcano Observatory continue to evaluate this earthquake sequence and will provide information to the NPS, USGS and the public as it evolves.
This earthquake sequence is the most intense in this area for some years. No damage has been reported within Yellowstone National Park, nor would any be expected from earthquakes of this size. The swarm is in a region of historical earthquake activity and is close to areas of Yellowstone famous hydrothermal activity. Similar earthquake swarms have occurred in the past in Yellowstone without triggering steam explosions or volcanic activity. Nevertheless, there is some potential for hydrothermal explosions and earthquakes may continue or increase in magnitude. There is a much lower potential for related volcanic activity….”
This has not stopped the hysteria.
One of the most recent press release on the subject was on Dec 29, nearly a week ago.
“…The University of Utah Seismograph Stations reports that a notable swarm of earthquakes has been underway since December 26 beneath Yellowstone Lake in Yellowstone National Park, three to six miles south-southeast of Fishing Bridge, Wyoming. This energetic sequence of events was most intense on December 27, when the largest number of events of magnitude 3 and larger occurred.
The largest of the earthquakes was a magnitude 3.9 (revised from magnitude 3.8) at 10:15 pm MST on Dec. 27. The sequence has included nine events of magnitude 3 to 3.9 and approximately 24 of magnitude 2 to 3 at the time of this release. A total of more than 250 events large enough to be located have occurred in this swarm. Reliable depths of the larger events are up to a few miles. Visitors and National Park Service (NPS) employees in the Yellowstone Lake area reported feeling the largest of these earthquakes.
Earthquakes are a common occurrence in the Yellowstone National Park area, an active volcanic-tectonic area averaging 1,000 to 2,000 earthquakes a year. Yellowstone’s 10,000 geysers and hot springs are the result of this geologic activity. A summary of the Yellowstone’s volcanic history is available on the Yellowstone Volcano Observatory web site (listed below). This December 2008 earthquake sequence is the most intense in this area for some years and is centered on the east side of the Yellowstone caldera. Scientists cannot identify any causative fault or other feature without further analysis. Seismologists continue to monitor and analyze the data and will issue new information if the situation warrants it….”