Central Idaho has been experiencing a rare outbreak of small and medium strength earthquakes that has confounded seismologists.
The U.S. Geological Survey is sending in three portable seismographs to the Challis, Idaho area to help experts understand what might be behind the outbreak.
“It certainly has gotten the attention of the state and our regional partners,” Harley Benz of the USGS told The Oregonian. “So what we’re trying to do is put in an array to get a better feel for the location of the events and the depths and the rate of activity.”
The largest quakes have happened since Thursday. The central Idaho region experienced a 4.1 magnitude quake Thursday, 4.9 on Sunday and a 4.4 on Monday. Dozens of other earthquakes under 3.3 magnitude has been happening on a semi-regular basis since March 24.
The region is the same as the deadly 1983 6.9 magnitude earthquake that is still the state’s strongest quake. However, the seismologists say the current quakes are happening on a previously thought dormant fault line and not the one that lead to the major 1983 quake.
A magnitude 8.2 earthquake off the coast of northern Chile left at least six people dead and injured hundreds.
The quake was significant enough that government and local officials forced an evacuation of the coastline in anticipation of a tsunami. The waves peaked out about 7 feet above normal before officials allowed residents to return 10 hours after the quake.
The only major damage from tsunami waves struck Iquique by flooding city streets and washing away fishing boats. The city was also hosting several military units after the quake caused the collapse of a wall in the city’s women’s prison resulting the escape of all 300 prisoners.
The U.S. Geological Survey said the quake had 20 aftershocks including one that registered magnitude 6.2. The initial quake was so large that the USGS reports the capital of neighboring Bolivia reported a 4.5 magnitude earthquake.
Mike Simons, a seismologist with the USGS, said that despite the intensity of the current quake, scientists are expecting a more massive quake to strike Chile.
“Could be tomorrow, could be in 50 years; we do not know when it’s going to occur. But the key point here is that this magnitude-8.2 is not the large earthquake that we were expecting for this area,” Simons said.
Californians have been keeping an eye on the San Andreas Fault for years fearing a “big one” would strike and cause massive damage.
Now, scientists say that a quake of 7.5 or bigger on a lesser known fault might be even more catastrophic than a quake along the San Andreas Fault line.
The Puente Hills thrust fault, which was the fault which brought Friday night’s 5.1 magnitude quake, runs from northern Orange County through downtown Los Angeles and all the way into Hollywood. The San Andreas Fault runs along the outskirts of Southern California’s metro areas.
Thus, scientists say, a massive quake along the Puente Hills fault would cause significantly more damage and likely brings hundreds or thousands of deaths. One estimate from the U.S. Geological Survey estimated as many as 1,800 deaths and $250 billion in damage.
The same fault in 1987 had a 5.9 quake that killed eight people and caused $350 million in damage.
One USGS staffer said that a 7.5 quake centered in Los Angeles would be so intense that it would throw heavy objects like a grand piano into the air.
A 4.8 magnitude earthquake rocked Yellowstone National Park Sunday morning, the strongest quake to strike the park since 1980.
University of Utah seismographic stations recorded the quake at 6:34 a.m. Sunday morning about 4 miles north-northeast of the Norris Geyser Basin.
The quake was far enough from residential areas to not cause significant damage but border towns in Montana about 20 miles from the epicenter reported significant shaking. Park rangers say that the park is very sparsely populated during this time of the year.
The USGS reported at least four aftershocks between magnitude 3.1 and 3.3.
Scientists have been watching the caldera of the Yellowstone Super Volcano closely as it has been rising since 2004, however, they said the recent quake is not the sign of an imminent eruption.
The quake comes less than two weeks after residents and reporters began to notice large migrations of bison and other animals away from the park. One video posted on YouTube March 20th showed a herd of bison running down a highway as if a predator was chasing them.
A major earthquake struck western Greece on Sunday afternoon.
According to the U.S. Geological Survey, a magnitude 6.0 earthquake struck around 3:55 p.m. local time. The quake was centered about 12 miles below the town Lixouri on the island of Kefalonia. At least a dozen aftershocks of 3.5 or higher on the Richter scale have continued to shake the region.
Officials say that no one was killed in the quake but that many suffered minor to moderate injuries from objects falling in their homes. Some roads and highways had to be closed for cracked pavement or large rocks from landslides caused by the quake.
Local Greek websites are showing pictures of moderate to severe damage to old buildings around the epicenter of the quake. Residents of the areas closest to the epicenter were told by government officials to abandon damaged buildings overnight in the event of major aftershocks.
“Not dead yet.”
That was phrase used by U.S. Geological Survey seismologist Susan Hough in a study published in the journal Science saying the major fault in the middle of the United States is still open to a major earthquake.
The New Madrid Fault Zone covers parts of seven states: Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri and Tennessee.
The study was in response to studies claiming the fault was dying down and that any seismic actions were aftershocks or results of the major 1811-1812 earthquakes that devastated the central Mississippi River valley. The fault is considered to be less understood than other major faults because unlike those faults, it is located in the middle of a continent away from plate edges.
Hough and a USGS geophysicist analyzed past quakes in the New Madrid region and through computer modeling determined they are not related to the big quakes 200 years ago.
The USGS estimates a 7 to 10 percent chance of a 7.0 or greater earthquake in the region within the next 50 years.
A major earthquake struck New Zealand’s north island on Monday shaking buildings and putting tens of thousands without power.
The 6.2 magnitude earthquake was centered about 70 miles northwest of Wellington, the nation’s capital, according to data from the U.S. Geological Survey. The USGS reported the quake was located about 17 miles deep. A series of weaker aftershocks continued through the afternoon and evening.
While there were no immediate reports of casualties, electricity was cut off for thousands throughout the region. All trains on the rail network were stopped for railway inspectors to investigate for cracks on the tracks.
The quake was strong enough to bring down a giant eagle statue hanging from the ceiling of Wellington’s international airport. No one was hurt by the falling sculpture although commuters had to scatter. Airport authorities are investigating how the sculpture could have fallen.
New Zealand is on the southwestern edge of the Pacific Ring of Fire.
A rise in Earthquakes in California and Alaska continued into a second day.
Alaska had three earthquakes strike in just over a two hour period. A 2.7 magnitude quake struck south of Seward, Alaska at 10:18. At 11:43, a 4.9 quake struck southeast of Whittier, Alaska with a second 3.0 magnitude quake hitting in the same area about 50 minutes later. Continue reading →