So Many Earthquakes Happen In The “Wrong” Places. You can add river erosion to the list of geological triggers capable of setting off an earthquake, according to new research: and it could help explain the reason why so many earthquakes occur far away from the edges of tectonic plates. “We’re taught in introductory geology that the vast majority of earthquakes occur at plate tectonic boundaries, such as in Japan and along the San Andreas fault zone” , says one of the team, Ryan Thigpen from the University of Kentucky. Because of the 1811-1812 earthquakes, the New Madrid area is recognized as a high-hazard zone for potential future seismic events. Lands sunk or were lifted and there were many landslides to go with it as well.
Each region will have its own characteristics of course, but experts have previously suggested the same combination could be causing earthquake activity in Missouri. “Previously, geologists have speculated about some of the driving mechanisms behind the seismicity but new and sometimes radical ideas are now allowing us to consider this from an entirely new perspective”, says Thigpen. High on the list of areas ripe for a great quake is Cascadia, the Pacific Northwest, where the risk for great quakes had long been under appreciated. What is certain is that studying these recent big earthquakes has given geophysicists the best information ever about how they work and point to new ways to begin understanding what could be in Cascadia’s future.
In 1811 and 1812, the region around New Madrid, Missouri, experienced a number of major earthquakes. The idea that earthquakes relieve stress on faults in the Earth’s crust makes intuitive sense and underlies the common assumption that the portion of a fault that has just experienced an earthquake is relatively safe for some time. Sometimes there may be very long intervals between earthquakes and sometimes the earthquakes may be more closely spaced. Those earthquakes around the Fox Creek area have registered as high as 4.5 on the Richter scale-strong enough to rattle dishes and pictures. “The background tectonic loading rate appear to be one of the predominant factors that control the region’s response to injection-induced earthquakes” , said Honn Kao, a seismologist with the Geological Survey of Canada and lead author.
In a new study, researchers looking at near-source seismic recordings from shallow crustal earthquakes have found that, within the first few seconds of rupture, large and small earthquakes appear indistinguishable from one another, hinting that initial rupture behavior may be universal among variously sized events. The National Science Foundation and the U. S. Geological Survey funded this research. We find that the Glorious Qur’an has addressed us 1400 years ago in a clear Ayah which reads: “And He has affixed into the earth mountains standing firm, lest it should shake with you”.
Where a tectonic plate dives under another, in the so-called subduction zones at ocean margins, many strong earthquakes occur. While most earthquakes take place along the major fault lines of the world that are located at the edges of the tectonic plates making up the Earth’s crust, that isn’t the case with the New Madrid earthquakes. The New Madrid Seismic Zone ( NMSZ ) lies far from a tectonic plate boundary, but has seen a number of major earthquakes, including events dated around 2350 BC, 900 AD and 1450 AD, apart from the one which took place in 1811-12.
To think of the tremendous force of the New Madrid quake, recall that the Richter scale, the common measure of earthquake magnitude, is logarithmic, with each increase by a whole number representing a tenfold increase in the power of the quake. An earthquake can happen at the most unexpected time. The findings support the idea that the area of large slip during a major earthquake is unlikely to rupture again for a substantial time. But not all studies have supported this, according to Thorne Lay, professor of Earth and planetary sciences at UC Santa Cruz. In the new study, published February 14 in Science Advances, Lay and other seismologists at UC Santa Cruz and Caltech took advantage of advanced slip-imaging methods applied to recent earthquakes of magnitude 7 or greater. In a study to be published in the Bulletin of the Seismological Society of America on Tuesday, the scientists presented “several lines of evidence [ that ] suggest the earthquakes in the area are directly related to the disposal of wastewater” deep underground, according to a BSSA press release.
Fracking and conventional natural gas companies routinely dispose of large amounts of wastewater underground after drilling. The study does note that despite the strong and direct link, the findings are not definitive, echoing language often used by climate scientists to describe why it’s nearly impossible to say that individual weather events are caused by climate change. Seismologists tend closer to the sites of the future epicenter, but “face to face” can not see and judge correctly. When it began erupting again on Sunday afternoon, it gave very little lead time, and as of yet has not produced a single earthquake large enough to be detected on its dedicated seismic network – the detection threshold is less than magnitude 1.
Plate tectonics involves some of the most powerful forces on Earth, but the lithosphere, of which the plates are made, is not infinitely strong: Weaknesses in the lithosphere allow it to break apart and form plate boundaries. It’s been long thought that, after forming – and subsequently undergoing additional uplift and deformation due to rifting during the opening of the Atlantic Ocean – the mountains fell dormant between about 160 million and 200 million years ago. But new work is adding to a growing body of evidence suggesting the ranges were tectonically active well after that. The Cascadia Subduction Zone ( CSZ ), off the Pacific Northwest coast of the United States and Canada, is one of the world’s most mysterious, and potentially dangerous, earthquake zones.
In mid-August 2010, the Columbia Glacier’s seismic activity changed radically from being relatively quiet to noisy, producing some 400 quakes to date. “Earthquakes of moderate magnitude occur much more frequently than powerful earthquakes of magnitude 7 to 8, and the probability of a moderate earthquake occurring in the New Madrid Seismic Zone in the near future is high”, the association reports. The plates then disperse or scatter and move away from each other, until they eventually – after another 400-600 million years – come back together again. While Japan and the Kamchatka Peninsula are active earthquake areas, the region of the Kuril Islands where the large November earthquake occurred, had not had a large earthquake since 1915 and researchers are unsure of the exact nature of that event.
In a new study in Geophysical Research Letters, researchers suggest that not only is it real, but that it is caused by radio waves induced by meteors and converted to sound waves near Earth’s surface. Plate tectonics is a revolutionary theory on a par with modern genetics. Our southern end of the San Andreas Fault has accumulated enormous stress that could blow in the form of major quake at any time, a Scripps geophysicist writes in the journal Nature after studying years of ground movement data. This warning came after a 4.4 magnitude earthquake shook in Tennessee on Wednesday.
Nepal’s last significant earthquake – 8.1 on the Richter scale – occurred in 1934. As climate warms, the Greenland ice sheet is melting, helping to fuel global sea-level rise. Do scientists have superhero powers? Iron particles catching a ride on glacial meltwater washed out to sea are likely fueling a recently discovered summer algal bloom off the southern coast of Greenland, according to a new study. The economics, in the jargon, are still not locked in. Mudslides, earthquakes, tropical storms and hurricanes are some of the natural disasters that strike countries in this area of the globe, including Mexico, with some regularity. Researchers from the University of Maryland have for the first time measured an effect that was predicted more than 40 years ago, called the Casimir torque. Students then gain information about Pangaea and plate tectonics, which assists them in drawing connections between the locations of the world’s most devastating earthquakes and major tectonic plates around the globe.
