The recent swarm of earthquakes noted at Yellowstone National Park were most likely caused by shifts in tectonic plates, not pressures in the magma chamber beneath the park, according to geologists.
According to the Yellowstone Volcano Observatory, University of Utah semismograph stations in the park noted a pair of earthquakes Sunday evening that measured magnitudes of 3.0 and 3.1. The first event of magnitude 3.0 occurred at 11:09 p.m. and was followed by a magnitude 3.1 event at 11:21 p.m., the observatory reported.
Both shocks were located around 9 miles southeast of West Yellowstone, Montana, and about 10 miles northwest of Old Faithful. Typically, events of this magnitude are felt in and around the park, but there were no reports of these particular events being felt, the observatory noted.
These two earthquakes are part of an ongoing swarm in Yellowstone that began January 17, 2010. The largest earthquake in the swarm as of 9 a.m. MST, January 25, was a magnitude 3.8, the observatory reported. There have been 1,271 located earthquakes in the swarm of magnitude 0.5 to 3.8. This includes 11 events of magnitude larger than 3, with 97 events of magnitude 2 to 3, and 1,163 events of magnitude less than 2. There have been multiple personal reports of ground shaking from observers inside the park and in surrounding areas for some of the larger events.
Earthquake swarms are relatively common in Yellowstone.
The swarm events are likely the result of slip on pre-existing faults and are called tectonic earthquakes and are not thought to be caused by underground movement of magma, the observatory staff noted. Currently, there is no indication of premonitory volcanic or hydrothermal activity, but ongoing observations and analyses will continue to evaluate these different sources.
Seismic information on the earthquake can be viewed at the University of Utah Seismograph Stations: http://www.seis.utah.edu/.
Seismograph recordings from stations of the Yellowstone seismograph network can be viewed online at: http://quake.utah.edu/helicorder/yell_webi.htm.
Anyone who has felt earthquakes in the swarm are encouraged to fill out a form on the USGS Community Felt reports web site: http://earthquake.usgs.gov/eqcenter/dyfi/.
Comments
What I want to know is, has any geologist gone out to examine the epicenter area? Seems to all be happening with in a 4 mile radius and at a shallow depth. In my mind it does not behave like any slip/strike fault. I would like to see more experts there figuring this out.
momie8x, why would it have to be a strike-slip fault? Why not a (normal or reverse) dip-slip fault? In any event, it'll be interesting to see the followup on this one.
The Movement of the earths crust sliding over the mantle may have been going on for over a billion years. The proof of this discovery was confirmed by the Chief Scientist of the Smithsonion Institute in a letter to me in 1976. I had checked the mid-point of the last 100 years of the "Chandler wobbles" and they ,the mid-point moves 4.+ inches per year westward. These 14 months circles about the size of a baseball infield can be caused by the pressure of the ocean tides ,but the movement is constant ,in one direction hinting of the "Free nutation " of the Earths Crust.
My research starts 34 years ago during the Arab oil embargo. It was curious that during the embargo the Mexican oil company brought in an oil well in the Bay of Campeeche, that produced over 100,000 barrels of oil per day. The other high producing oil wells around the world were in venezula, Nigeria ,Arab Desert Russian "Stans ,Prudhoe bay ,Texas ,Oaklahoma ,and we have a circle of high producing oil wells around the globe.
The mid point of this curious circle was between Iceland and Great Britian, and this was opposite the Pacific Ocean.
My research followed these curiosities for 34 years?
My book "The Origin of Mountains", explains fully this movement of the earh crust and how its cause mimics the Plate movement in the erroneous Plat Tectonic theory.
[email protected] If you e-mail me I will attach a free copy of my book.
John Delano
Tectonic Plate? The nearest one is almost a thousand miles away.
geesh who writes this stuff?
Raven, a year ago, during another period of swarms, the park's geologist explained that those quakes could have been tied to strains and stresses in the lithospheric plate beneath the park.
Yellowstone is situated on the North American Plate, one of the largest tectonic plates on the surface of the earth. I wonder if Raven is confusing tectonic plate with plate boundary/margin?
Here are some facts to prove earth lithosphere is "sliding" over the mantle.
The 5 ancient calderas of Yellowstone moved from west to east over a 16 million years period.
The Juan Defuca ridge line offshore Washington State has an age that is 16 million years younger moving from west to east.
The columbia Plateau has 45 , massive lava flows one on top of another, and they form steps that are consistently 45 to 60 feet high, and are younger by as you go from bottom to top and from west to east. Experts place the aage of this large igneous plateau at 24 million years for it's formation.
The reason for the step formations around the world can be traced to the orbital cycle of planet earth.
My 34 years of research shows the 45 steps of the Columbia Plateau and the 12 major other step formations and lava flows around the Planet will reflect the extreme orbital ellipitical cylcle M Milankovich described ias his most extreme orbital cycle. A orbital cycle where centrifical forces are so extreme as to cause large objects on the surface of the planet to be forced with greater force toward the Equator. M. Milankovich died before he witnessed anything in the geology of Planet Earth that proved this extreme ellipitical orbit cycle, Everyon knows about the 100,000 year eb and flow of the glaciers in the last 2 million years were in tune with M. Milankovich's 100,000 years elipitical orbits, but never saw any indication of the 413,000 year cycle. It was indicated in the large igneous lava flows around the world and at the bottom of the oceans.
It was hidden under the ocean waters of Earths massive oceans. In the ocean basins are 40,000 miles of ocean ridges, and every 41.3 miles ,on average is crossed by a ridge hundreds or thousands of miles long, an ocean ridge called a"Transform fault". Thes faults were discovered by the Lansat Satillite that created a picture for the first time of the ocean floor, and is the first time the world could witness the 413,000 years effect in the geology of this massive ellipitical cycle.
A little history:
The Pacific Ocean , was first a hollow. It was formed 4.5 billion years ago in the aftermath of the moon forming collision at that time. This Pacific hollow filled with all the liquid water on the planet. Once the water frooze, the returning radioactive mantle material moved in to repair the damabe and in doing so raised the ice mass to great heights. It raised the ice mass to became an 18 mile high ice cap on 1/2 the Planet!
My discovery of this has been docuemented in the book "The Origin of Mountains", and contains to many facts and dicoveries to describe in this comment.
to be continued
John Delano, could you give us a little background into who you are and what qualifications you carry as a geologist or geophysicist? Your posts here refer to several things I've never heard of as if they are accepted theories. I'd be interested in learning more about you -- and them.