For many years, John Anderson, director of the Nevada Seismological Laboratory at the University of Nevada, Reno, has been telling citizens, reporters and other scientists from throughout the world that in terms of seismic activity in the 50 states, Nevada ranked as the third most active.
Then, during a meeting of the Nevada Earthquake Safety Council earlier this year, he learned that the United States Geological Survey (USGS) website actually ranked Nevada fourth, behind third-place Hawaii.
"One of the Safety Council members said, 'John, what in the world is going on here?'" Anderson remembered.
His curiosity piqued, Anderson began a study along with Yuichiro Miyata of the Nevada Seismological Laboratory to take another look at the data. The project turned into a national study, and their lists of the top 10 most seismically active states have just been published in the November/December issue of Seismological Research Letters, a bimonthly publication of the Seismological Society of America.
The undisputed leader for numbers of earthquakes? Alaska, of course, with California solidly in second place. But beyond that point, depending on how you measure activity, the rankings change. On the list that Anderson likes the best, which gives the greatest magnitude that is reached once per year on average, Nevada inches into third, at 5.1. For fourth-place Hawaii, it's 5.0.
The top 10 rankings, based on the magnitude of earthquake that occurs once per year on average: 1, Alaska, 6.70; 2, California, 6.02; 3, Nevada, 5.11; 4, Hawaii, 5.00; 5, Washington, 4.97; 6, Wyoming, 4.67; 7, Idaho, 4.57; 8, Montana, 4.47; 9, Utah, 4.29; 10, Oregon, 4.24.
"Everybody is dedicated to accurately portraying how and when earthquakes occur," said Anderson, who, as director of one of the nation's premier seismological laboratories, monitors such events on a daily basis. "The reason for talking about this is not to change the rankings or to have one state move ahead of another – it's to motivate people to build structures that resist earthquakes. If you're on this top-10 list, hopefully it will motivate you to be better prepared in the event of a large earthquake."
The lab, part of the University's College of Science and Mackay School of Earth Sciences and Engineering, records earthquakes in Nevada and parts of eastern California, as part of the U.S. Geological Survey's Advanced National Seismic System (ANSS). It also operates a seismic network in southern Nevada for the U.S. Department of Energy.
To determine the rankings, Anderson and Miyata consulted the ANSS catalog of earthquakes, which contains earthquake data from 1898 to 2005. They then supplemented this catalog with data from the USGS catalog of significant U.S. earthquakes from 1568-1989.
Miyata's participation as a GIS expert was also key, Anderson said.
"Yui is a GIS expert, and a graduate of our Department of Geography," Anderson said. "With GIS, it's very easy to sort out how many earthquakes have occurred with each state's borders."
"It only took a couple of days," Miyata said. "First, we took the whole earthquake catalog and divided it by state. And, we made sure that with states with coast line, we extended the borders to go about 100 kilometers (about 62 miles) beyond the coast."
In this way, the study was able to take into account seismic "hot spots" that exist undersea, and underneath, a state such as Hawaii.
Many earthquakes, including the magnitude-6.7 event that occurred in Hawaii recently, causing upwards of $50 million in damage, are driven by stresses set up on the flanks of active volcanoes by accumulated magma intrusions. Due to this concentrated volcanic source, Hawaii has a large number of smaller earthquakes. Seismicity in top-ranking states of Alaska, California and Nevada, however, is driven by plate tectonics, Anderson said.
For those keeping score, the difference in seismic activity between Nevada and Hawaii is not great, Anderson added.
"In terms of magnitude-7 earthquakes, Nevada and Hawaii are essentially tied, but in terms of magnitude-5 and greater earthquakes, Nevada is ahead," Anderson said. "Then, counting magnitude-3.5 and greater, Hawaii again leads. Considering the uncertainties, Nevada and Hawaii are essentially tied."
Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union
Enormous dome in central Andes driven by huge magma body beneath it
25.10.2016 | University of California - Santa Cruz
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering