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Show 4 ALL SHOOK UP: Concerns and Explanations on the Recent Quakes BY GREGORY GERULAT B etween Feb. 11 and Feb. 13, the citizens of Lehi claimed to have felt the Earth move under their feet, and unlike those of us who have sung karaoke to Carole King before, they were being completely serious. On Friday and Sunday, the city of Lehi and surrounding rural areas reported feeling a total of three quakes. According to the University of Utah Seismograph Station, the first quake struck roughly around 7:38 p.m. on Friday night with a reported magnitude of approximately 2.5. The second, a 2.6, jolted residents awake around 2:25 a.m. on Sunday morning, and the third, a 2.8 and the biggest of the three, rattled residents one final time, concluding the triplet at 6:09 p.m. So while the rest of Utah County were gathering up roses and boxes of Russell Stovers in preparation for Valentine's Day, some of the constituents of Lehi were gathering up food storage and 72hour kits in alertness of a possible impending natural disaster. Although some of us may be privy to the exact causes and explanations of a quake, many people may dismiss it as some unknown phenomenon related to volcanoes, some kind of movement to do with underground plates, or one of the innumerable apocalyptic theories that have been circulating around in the mainstream lately. According to geologists, there are two main types of earthquakes: tectonic earthquakes and volcanic earthquakes. Tectonic earthquakes are caused by tectonic activity, which triggers when the Earth's crust, comprised of many floating plates, becomes subjected to and moves freely because of strain. During these strain-induced movements, the plates can come towards each other, move away from each other or try to slide past one another. The first and third are the main causes of the earthquakes that we feel, being most commonly near the plate's margins or a fault — a break in continuity along planes of rock. The causes of the Lehi quakes are related to faults, and according to Mark Milligan of the Utah Geographic Survey, we're host to quite a few of them, and possibly a single massive one. "All of the faults within Utah County are related to the great Wasatch Fault that runs parallel to the Wasatch Mountains all throughout Utah." says Milligan. "The quakes that have taken place in Lehi were due to one of the numerous smaller faults, most possibly due to ones that are under Utah Lake, as there are quite a few of them there." While we commonly feel tectonic earthquakes the most often, volcanic earthquakes are the sort which get the most spotlight and coverage in Hollywood films. olcanic earthquakes are seismic motions that are caused by the sporadic movement of magma usually underneath the Earth's crust and within the mantle, inducing pressure changes in the areas of rock in which the magma goes under stress. They usually occur above or around "hot spots" — specific regions within the mantle where the temperature is comparatively higher than the areas surrounding it. Although Utah has no "hot spots," there is a significant one pretty near by — the Yellowstone Park Caldera. "Hot spots are basically long volcanisms within the mantle and oceanic lithosphere," says Henry Heasler, PhD volcanic geologist and coordinating scientist for Yellowstone National Park. "It's a very complex process to what exactly happens underground, but basically the plates are moving above very centered and focused heat sources, where rocks are melted and magma is generated. In turn, these [plates] push against the subsurface continental layers and produce clusters of earthquakes otherwise known as 'earthquake swarms." Many citizens, like those in Lehi who were caught in a brief physical example of all of this geological jargon, have reported that they're afraid that the two types of quakes may be interconnected — specifically, it may be a warning sign of a fabled, gargantuan 8.0 quake. Moreover, they fear that the recent quakes may be connected to a possible volcanic eruption. Are these legitimate concerns and worries, and should we start preparing for a cataclysmic |