Tag Archives: earthquakes

Oklahoma hit by more than 400 earthquakes in first two months of 2016

Oklahoma was shaken by more than 400 earthquakes in the first two months of 2016, the latest in a state that has experienced a marked increase in seismic activity in recent years.

U.S. Geological Survey (USGS) data shows the Sooner State experienced about 430 earthquakes of magnitude 2.5 or greater in January and February, an average of more than seven per day.

About 240 quakes of that magnitude occurred elsewhere in the continental United States during the same time frame, according to a searchable earthquake archive on the USGS website.

Magnitude 2.5 is the minimum strength reported on the USGS’s earthquake tracker.

Oklahoma rarely experienced earthquakes of that size before 2009, when the state’s seismic activity began to surge. USGS data shows the state was hit by about nine earthquakes of magnitude 2.5 or greater in 2008, and that number rose to more than 2,700 last year.

The uptick has been linked to wastewater produced by the oil and gas industries, and state officials have taken steps to limit the amount of wastewater that can be disposed in wells.

Both the USGS and Oklahoma Geological Survey have issued warnings about the increase in earthquakes of magnitude 3.0 or greater, saying the rise in quakes of that size increases the odds that Oklahoma will experience a larger, potentially more damaging earthquake in the future.

USGS data shows Oklahoma felt about 169 quakes of that size in January and February. The rate, an average of more than two per day, places it on pace to break the 2015 total of about 900.

The agency has said that Oklahoma’s average was about two per year between 1978 and 2008.

This year’s events include a magnitude 5.1 earthquake that occurred on Feb. 13 near Fairview. That is the state’s third-largest quake on record, according to the Oklahoma Geological Survey.

Three days later, the Oklahoma Corporation Commission announced it was implementing its biggest plan to reduce wastewater disposal yet, affecting 245 disposal wells across more than 5,200 square miles. Researchers recommended the plan should be implemented gradually over the next two months to avoid sudden pressure changes, the commission said in a news release.

In late January, Oklahoma Governor Mary Fallin announced that $1.4 million would be withdrawn from the state’s emergency fund and given to earthquake researchers and regulators.

Quakes in Oklahoma, Kansas and Texas rise as global averages remain constant

The central United States saw a rise in seismic activity last year, seismologists said Monday.

Kansas, Oklahoma and Texas combined to witness 32 earthquakes of at least magnitude 4.0 in 2015, the United States Geological Survey (USGS) said in a news release announcing last year’s global earthquake totals, nearly doubling the 17 quakes of that size that hit those states in 2014.

The news will hardly surprise residents of Oklahoma, which has seen a dramatic rise in quake frequency and magnitude since 2009. Officials have linked the surge to wastewater from oil and gas companies operating in the state, and regulators have taken steps to reduce its production.

Globally, however, the USGS said last year’s quake totals were “on par with prior year averages.”

The world usually sees about 14,500 earthquakes of magnitude 4.0 or greater and 18 earthquakes of magnitude 7.0 or greater every year, according to the USGS. Last year, those totals were 14,588 and 19, respectively, though the numbers may change pending a final review.

While earthquake totals might not have increased, the USGS reported they were far deadlier.

The organization said earthquakes killed 9,612 people last year, up from the 2014 total of 664.

Nearly 9,200 of them were killed in magnitude 7.8 and 7.3 earthquakes that hit Nepal in April and May, the USGS said. The first and more powerful quake on April 25 killed 8,964 people, and 218 died in the May 12 quake. Another 430 died in quakes in Afghanistan, Malaysia and Chile.

While Kansas, Oklahoma and Texas saw some powerful earthquakes, they didn’t see the most powerful one to hit the United States last year. A magnitude 6.9 earthquake off the coast of Alaska’s remote Unmak Island in July holds that distinction, according to the USGS.

However, Oklahoma’s trend of increased activity appears to be carrying over into the New Year.

The state has already seen seven earthquakes of magnitude 4.0 or greater in 2016, USGS data indicates. This year’s quakes include a Jan. 6 magnitude 4.8 earthquake near Fairview that is one of the strongest in the state’s history, according to Oklahoma Geological Survey records.

Oklahoma experienced just 21 earthquakes of magnitude 4.0 or greater in a 64-month stretch from January 2009 to May 2014, the USGS said in a news release at the time. That included a magnitude 5.6 quake that hit near Prague in November 2011, the state’s strongest on record.

Both the USGS and Oklahoma Geological Survey have cautioned the rise in Oklahoma’s earthquake activity increases the risk that the state could see an even bigger quake.

Oklahoma isn’t the only state where earthquakes pose a risk to the public.

The USGS reported last August that about 143 million people in the continental United States live in areas where they could be exposed to potentially damaging earthquake tremors. That was nearly double its previous estimate of 75 million people, published in 2006. The organization said the rise was the result of population shifts and a better understanding of seismic activity.

California, Washington, Utah, Tennessee, Oregon, South Carolina, Nevada, Arkansas, Missouri and Illinois are the states with the most people exposed to potentially damaging shaking, the USGS said.

Major earthquake in southern Alaska felt for hundreds of miles

JUNEAU, Alaska (Reuters) – A powerful 7.1 magnitude earthquake struck remote southern Alaska early on Sunday, unleashing shudders felt several hundred miles from the tremor’s lakefront epicenter at the far end of Cook Inlet from Anchorage, the state’s largest city.

No injuries were reported, but several neighborhoods in the town of Kenai – roughly halfway between the quake’s center and Anchorage – were temporarily evacuated after a gas explosion damaged four homes several hours later, a city spokesman said.

As of Sunday night, local utility company Enstar was still investigating whether the earthquake triggered a gas leak believed to have caused the blast, company spokesman John Sims said.

There were also reports of brief power outages in Anchorage, about 160 miles southwest of the epicenter, and cities immediately to the north and south.

The quake, initially reported at a 7.3 magnitude, struck at 1:30 a.m. about 30 miles east-southeast of Pedro Bay on the shore of Iliamna Lake, at the foot of a mountain chain just west of Cook Inlet, the U.S. Geological Survey (USGS) reported.

The quake was felt as far away as Whitehorse, the capital of Canada’s Yukon Territory more than 600 miles east of Anchorage, according to the USGS.

It was recorded 79 miles beneath the surface, a depth that helped keep damage to a minimum, said Dara Merz, a research technician with the Alaska Earthquake Center in Fairbanks.

“If you take into account how deep it was, that’s a lot of earth and rock that seismic waves have to work through to get to the surface,” Merz said.

The Fairbanks agency reported a series of aftershocks reaching magnitudes of up to 4.7, though Merz said even larger tremors could follow.

Alaska, a seismically active state, records anywhere from 80 to 100 quakes daily, most of them hardly ever noticed. One of the more powerful quakes to hit Alaska in recent years was a 7.9 magnitude temblor that struck beneath the ocean floor near the Aleutian Islands chain in June 2014, but it caused no injuries or major damage.

Following Sunday’s quake, jittery Anchorage residents and hotel guests who briefly fled their buildings took to social media sites to share their experiences. Some posted photos of stores with aisles littered by fallen merchandise knocked off shelves to the floor.

The quake produced no tsunami threat, according to the U.S. Pacific Tsunami Warning Center.

(Reporting from Juneau by Steve Quinn; Writing by Steve Gorman; Editing by Sandra Maler and Tom Hogue)

Indonesia, Japan hit by magnitude 6.0-plus quakes 30 minutes apart

A pair of magnitude 6.0-plus earthquakes occurred within 30 minutes of each other on Tuesday.

Both earthquakes were located in the Pacific Ocean, hundreds of miles apart. Neither earthquake produced reports of significant damage and no tsunami warnings were issued.

According to the United States Geological Survey, a magnitude 6.5 earthquake occurred in the water between Indonesia and the Philippines at 12:38 a.m. local time. A half-hour later, the USGS reported a magnitude 6.2 earthquake deep below the Earth’s surface in the Sea of Japan.

The first quake was centered a few miles southeast of the Talaud Islands of Indonesia, and the USGS reported the tremors caused strong shaking there. While the quake was more than 100 miles away from larger cities, user-submitted data published on the USGS website indicated some people reported weak shaking approximately 200 miles away in Manado, Philippines.

The earthquake was triggered about 13 miles below the Earth’s surface, the USGS reported, while the earthquake that followed in Japan occurred at a much larger depth of 150 miles.

The Japan earthquake was centered about 46 miles northwest of Rumoi and 610 miles north of Tokyo. But because it occurred so far underground, those on the surface didn’t feel its full effect.

The Japan Meteorological Association reported most parts of the country experienced a 2 on its own seismic scale of 0-7, which usually carries only weak shaking and can be undetected by humans.

Oklahoma earthquakes raise calls for restrictions on energy firms

OKLAHOMA CITY (Reuters) – Earthquakes in Oklahoma in the past week, including one of the strongest ever recorded in the state, have led to calls for the governor to make changes to oil and gas drilling regulations and reduce seismic activity scientists link to the energy industry.

Two large earthquakes were recorded in northwest Oklahoma on Wednesday, including a magnitude 4.8 quake. The quakes were part of a surge in seismic activity over the past several years.

Scientists have tied a sharp increase in the intensity and frequency of quakes in Oklahoma to the disposal of saltwater, a byproduct of oil and gas extraction, into deep wells. Oil fields have boomed in Oklahoma over the past decade thanks to advances in hydraulic fracturing and horizontal drilling.

State Representative Richard Morrissette, a Democrat who has said the state’s Republican leaders are not doing enough to address the problem, will host a public forum at the Capitol on Friday to discuss the rash of earthquakes.

He wants the state to halt operation of injection wells at quake sites and do more to prevent them from causing quakes.

“No one in a position of authority is taking this seriously,” said Morrissette, who accused the state’s leadership of bowing to pressure from the energy industry.

Morrissette is hoping to build grassroots support to take on the oil and gas drilling industry, a powerful player for decades in the state and a major source of employment.

The industry is Oklahoma’s largest source of private capital spending and tax revenue and accounts for about 10 percent of the state’s annual economy, according to the Oklahoma State Chamber, which represents more than 1,000 Oklahoma businesses.

Although the quakes last week caused no major reported damage or injuries, they left many Oklahomans shaken. Firms providing quake insurance saw a surge in calls inquiring about coverage.

“We don’t have overall data on how much injection is going on in this area, but we attribute most of the earthquakes these days to deep injection of produced oil wastewater,” said Jerry Doak, director of the Oklahoma Geological Survey.

State leaders have been instituting changes, but critics said they have not gone far enough.

In response to the quakes, Governor Mary Fallin, a Republican, said last week that the state has been regulating disposal wells, taking some steps to limit their injection rate and depth of their injections.

“Science is ever-evolving as to what actually causes earthquakes. We know that disposal wells can cause earthquakes, but not all earthquakes. There are fault lines that are just natural in Oklahoma,” she told The Oklahoman newspaper.

Energy companies have also been responding.

Phillips 66 has overhauled how it plans for earthquakes, a sign U.S. energy companies are starting to react to rising seismicity around the world’s largest crude storage hub in Cushing, Oklahoma, site of many disposal wells.

The changes include new protocols for inspecting the health of crude tanks, potentially halting operations after temblors, and monitoring quake alerts.

(Reporting by Heide Brandes; Writing by Jon Herskovitz; Editing by Cynthia Osterman)

Oklahoma city shaken by 20 earthquakes in 9 hours

A small city in Oklahoma was hit by 20 earthquakes in nine hours overnight, including a pair of particularly strong ones just 30 seconds apart, the United States Geological Survey (USGS) said.

The earthquakes occurred between 10:27 p.m. and 7:40 a.m. and were centered just northwest of Fairview, a city of about 2,600 people that sits about 100 miles northwest of Oklahoma City.

The swarm began with magnitude 4.7 and magnitude 4.8 earthquakes 30 seconds apart. The second quake was the strongest in the state since November 2011, according to the Oklahoma Geological Survey, and only three stronger earthquakes have occurred in Oklahoma since 1882.

The 18 quakes that followed ranged in magnitude from 2.5 to 4.0, USGS data indicates.

The strongest earthquake could be felt more than 100 miles away in other parts of Oklahoma, Kansas and Texas, according to user-submitted reports published on the USGS website. There was no indication that any of the 20 earthquakes caused any significant damage or injuries.

Last April, the Oklahoma Geological Survey issued a statement saying the state’s seismicity rate was 600 times greater than it was before 2008. Wastewater from the oil and gas companies that operate in the state has been linked to the rise, and the Oklahoma Corporation Commission has taken steps to limit the amount of wastewater in an attempt to reduce the overall risk of quakes.

The Oklahoma Corporation Commission on Monday announced additional steps it would take to limit such waste near Edmond, which had felt two sizeable earthquakes in recent days — a magnitude 4.3 earthquake on Dec. 29 and a magnitude 4.2 earthquake on New Year’s Day.

But USGS data indicated three smaller earthquakes occurred near Edmond between 7:20 p.m. Wednesday and 12:42 a.m. Thursday. The tremors ranged in magnitude from 2.5 to 3.2.

Edmond, one of Oklahoma’s largest cities, is located 15 miles northeast of Oklahoma City.

The Oklahoma Geological Survey and USGS have both warned the increase in large earthquakes — those greater than magnitude 3.0 — puts Oklahoma more at risk for even bigger earthquakes.

Earthquakes Rock Oklahoma, Kansas, Oregon

A series of earthquakes were felt in the United States Wednesday afternoon and Thursday morning.  

A magnitude 4.0 earthquake was reported Wednesday afternoon 43 miles from Lakeview, Oregon, according to the Geological Survey.  The tremor occurred at 5:50pm Pacific Time.  In the last 10 days, there has been one other earthquake of magnitude 3.0 or greater centered nearby.

This morning residents in Oklahoma were awakened by a 4.7 magnitude quake that is reported to be the largest in that state since 2011.  The earthquake was felt from Norman, Oklahoma, to central Kansas, and from the Texas Panhandle to Missouri, the U.S. Geological Survey (USGS) reported.

The epicenter was 8 miles southwest of Cherokee, Oklahoma with a depth of 3.8 miles.  

“It was a quick jolt with windows rattling with [the first waves], then 5-10 seconds later, [the second waves] rattled windows and shook appliances and computer monitors,” said AccuWeather Enterprise Solutions Meteorologist William Clark, who felt the earthquake in Wichita, Kansas.

Local radar picked up thousands of birds that took off as the quake hit.  

Three other earthquakes were reported overnight in the area Thursday: a 3.1-magnitude at 3:46 a.m., a 3.7-magnitude earthquake at 6:03 a.m. and a 3.4 magnitude earthquake at 7:25 a.m. The 3.1 and 3.7 magnitude tremors were centered 9 miles west of Cherokee near the Kansas border. The 3.4 was centered near Crescent.

It is unclear if there was any damage or injuries at this time.

A strong undersea earthquake also struck off the coast near the Solomon Islands, according to the Bureau of Meteorology. These islands are located east of Papua New Guinea.  

The bureau initially reported that an earthquake of 7.1 had occurred at 5.31am ADET, which would be classified as a major earthquake, but the intensity was later reported as 6.8, which is considered strong.

The quake struck 119 kilometres south west of Dadali, in the Solomon Islands, and 176 kilometres north west of the capital, Honiara.  There are no reports of injuries and no tsunami watches or warnings issued.  

3 Small Earthquakes Hit Central Arizona

Central Arizona was rattled Sunday night after experiencing 3 small earthquakes within a 3 hour period.

The United States Geological Survey (USGS) reported that the first earthquake had a 3.2 magnitude and struck just before 9 p.m. local time. At 11:29 p.m., a 4.1-magnitude earthquake struck the same area, and twenty minutes later, a 4.0-magnitude earthquake took place, according to Weather.com. No injuries or damages have been reported.

All three earthquakes were centered around Black Canyon City which is located about 45 miles north of Phoenix, and they ranged between 3-6 miles in depth.

“In general, it’s relatively small,” Zachary Reeves of the USGS said of the magnitude-4.1 peak earthquake Sunday, the largest of the series. “If people are in bed then people may not even be woken up by it.”

Residents in Phoenix did feel tremors from the quake. Geologist Michael Conway, chief of the Geologic Extension Service of the Arizona Geological Survey, told ABC News that central Arizona region has several inactive and active faults that reach throughout the state.

Since the USGS began keeping records of earthquakes, Arizona has seen 11 earthquakes of magnitude 4 or greater, and two of those 11 occurred on Sunday night.

Earthquakes Shake Oklahoma; San Francisco

The last 24 hours have shown active seismic activity in the Midwest and on the West Coast.

A significant magnitude 4.4 earthquake struck Oklahoma Monday afternoon near the town of Cherokee, OK.  The shaking of the quake was reported outside the Sooner State in Arkansas, Kansas, Missouri and Texas.

The U.S. Geological Survey (USGS) also reported a second quake striking near Pawnee, OK about half an hour later with a magnitude of 3.2.  Then a few minutes after the Pawnee quake, a second quake struck in the area of the Cherokee quake that measured 3.7 on the Richter scale.

The USGS said all the quakes were around three miles deep.

Local officials said there were no injuries or significant damage from the quakes.

In San Francisco, a magnitude 4.0 quake struck the San Francisco area on Tuesday.

The USGS says the quake struck around 2:30 a.m. near Fremont, or 35 southeast of San Francisco.  The quake struck at a depth of 5 miles.

No injuries or significant property damage was reported in the Fremont quake.

Quakes Shake Oregon, Alaska, Utah

The Fourth of July weekend had more than fireworks shaking things up in Utah, Oregon and Alaska.

Oregon residents started their day out in an unusual way when a 4.2 magnitude quake struck around 8:42 a.m. Saturday.  The quake was centered about 12 miles east of Eugene.

Officials from the Lane County Sheriff’s office and the Oregon Department of Transportation reported no damage being reported.  Residents say that the quake caused some shaking of homes, pictures to fall off walls and wood piles to shift.

In Utah, a 4.0 magnitude quake struck around 10 a.m., 1 mile south of Panguitch or 200 miles south of Salt Lake City.

Panguitch Fire Chief Dave Dodds told the Deseret News the quake lasted between three and four seconds but caused no major damage.

Alaska was the most shaken up with weekend quakes.

The U.S. Geological Survey reported Alaska was shaken by two quakes within one minute.

The first, a 4.9 magnitude quake, struck around 4:49 p.m. about 24 miles southwest of Talkeetna.  The second quake a minute later in the same area was reported at magnitude 5.1.

Also, the Arctic community of Kaktovik in the Arctic Ocean reported a quake around 11:26 a.m. that measured 4.6 according to the USGS.