Mount Etna Erupts! Italian Volcano Spews Ash And Lava

Mount Etna, the famous Sicilian volcano, turned on the fireworks Wednesday (Jan. 12) as it shot lava hundreds of feet into the air.

Volcanic tremors at Mount Etna, on the Italian island, were detected around 21:00 GMT (4 p.m. EST) on Jan. 11. The tremors peaked the next morning and lava began erupting at the Southeast Crater, about 4,500 feet (1,375 meters) high. The crater pit overflowed with lava and ash plumes spewed into the air, which forced a local airport to halt service. The ash plumes had stopped by about 3:30 p.m. local time today (Jan. 13), according to the Italian Institute of Vocanology (INGV), citing surveillance cameras observing Etna.

But more eruptions could be on the way, scientists said.

"This eruption is very similar to more than 200 episodes of lava fountaining at the summit craters of Mount Etna — including 66 from the Southeast Crater in the year 2000," said Boris Behncke, a volcanologist and expert on Mount Etna. "The same vent that erupted last night already produced nearly identical — though longer-lasting — episodes in September and November 2007 and most recently on May 10, 2008."

Etna is the largest active volcano in Europe and one of the world's most well-known. While 2010 was an exceptionally calm year for Etna, it is nearly constantly active and there is rarely a full year that passes without some eruptive activity on Etna, Behncke told OurAmazingPlanet.

"We expected Etna to return to activity in this period," Behncke said. "There had been lots of premonitory signals."

Two episodes of much weaker activity at the same vent that erupted last night — one on Dec. 23 2010, and the next on Jan. 2 and 3 of 2011 — suggested that a larger eruption was on the way.

"We expected further episodes at similar intervals, and also thought they would get stronger with time," Behncke said. "Things did accelerate maybe a tiny little bit faster than we had imagined, but the evolution was very logical, and again, very similar to many events in the past."

Etna's lava fountaining may go on for weeks or even months, similar to past episodes such as the series of 66 lava fountains during 2000, which lasted seven months, Behncke said.

At a height of 10,900 feet (3,328 meters), Etna looms over the city of Catania. As active as the volcano is, it's not a pressing danger to locals, and no damage or injuries were reported or expected from yesterday's eruption. Etna's most violent eruption was in 1669, when 15,000 people were killed.

The eruption is what's called a strombolian explosion, named after the nearby volcano of the same name that has been erupting for hundreds of years. Bursting gas bubbles within the magma drive these explosions, which eject lava tens to hundreds of meters into the air from a single crater. These episodes happen every few minutes, rhythmically or irregularly. The lava fragments — volcanic bombs — are rounded as they fly through the air.

The ancient Greeks believed Mount Etna to be the home of Vulcan, the god of fire. To them, Mount Etna erupting merely meant Vulcan was forging weapons for Mars, the god of war.

Reach OurAmazingPlanet staff writer Brett Israel at bisrael@techmedianetwork.com. Follow him on Twitter @btisrael.

Ice Mission Accomplished: Antarctic Survey Wraps Up

After weeks of flying hours-long missions over the barren icescape of Antarctica, NASA's IceBridge campaign has come to a close for the season, and scientists hope it yields a better picture of the changes happening on the southernmost continent.

Operation IceBridge began in 2009 using specialized instruments aboard aircraft to collect data about the thickness of Arctic and Antarctic ice on both sea and land and how fast glaciers are moving, to better understand potential impacts from the poles on global sea-level rise. The Antarctic campaign is conducted in Northern Hemisphere autumn (the Southern Hemisphere's spring), while the Arctic campaign flies in the Northern Hemisphere spring.

The 2011 Antarctic mission began in October with IceBridge's Gulfstream V and DC-8 planes taking off from their base in Punta Arenas, Chile, and flying particular paths over the Antarctic ice. The flights, which typically last 10-to-11 hours, take the same routes year-to-year to better observe the changes happening there.

The early flights focused on sea ice, before too much of it melted with the warming temperatures of the austral spring. IceBridge sea-ice flights are designed to help scientists understand why sea ice in the Southern Hemisphere is not thinning to the same extent seen in the Arctic. [Images: IceBridge in Action Over Antarctica]

On Nov. 9, the team made its longest flight of the mission to date, a 12.5-hour flight on the DC-8 to the Thwaites Glacier and eastern Byrd Land, including overflights of ice-core-sample locations. This flight also reached the most southerly point of any of the IceBridge flights, with a latitude just short of 80 degrees south.

"Upon reaching the Amundsen Sea, the weather was not at all promising, but after a short time, it cleared up and conditions remained favorable for the rest of the day," Pilot-in-Command Troy Asher of NASA's Dryden Flight Research Center said in a statement. "The research area was like Kansas in Antarctica, flat for as far as the eye could see in all directions."

After a delayed takeoff to allow weather over the target area to clear, the team was back in the air Nov. 11 for a low-level return flight over the Thwaites Glacier. As a bonus, it also flew a now-famous crack that recently broke across the Pine Island Glacier to get data with its topographic mapper.

Sunlight glistens across the water and the ragged edge of the Pine Island Glacier ice shelf during a low-level pass by NASA's DC-8 flying laboratory during an IceBridge mission flight Nov. 11.
Sunlight glistens across the water and the ragged edge of the Pine Island Glacier ice shelf during a low-level pass by NASA’s DC-8 flying laboratory during an IceBridge mission flight Nov. 11.

Credit: NASA

"The view was spectacular of both the rift and glacier edge under sunny skies," said NASA Dryden Mission Manager Chris Miller, who noted that the glacier rift should create a calving iceberg anytime between a few weeks from now and a few months.

Earlier in the mission, the team also flew over Pine Island Glacier to take new measurements over areas where a drilling mission will be on the ground in a few weeks to take up-close measurements and drill cores of ice from the glacier to better understand its movements and potential to melt. Pine Island Glacier is the fastest-moving glacier in western Antarctica, gliding at a clip of about 2.5 miles (4 km) per year.

An 11.2-hour flight Nov. 13 took the IceBridge team over the Crosson Ice Shelf, with some of the data-collection flight tracks extending over the Thwaites and Dotson ice shelves and over Mt. Murphy in between.

Jagged rocks and precipitous snow banks were just outside as NASA's DC-8 flying laboratory crested a mountain range during a low-level science flight over the Antarctic Peninsula Nov. 16.
Jagged rocks and precipitous snow banks were just outside as NASA’s DC-8 flying laboratory crested a mountain range during a low-level science flight over the Antarctic Peninsula Nov. 16.

Credit: NASA/Chris Miller

On Monday, Nov. 14, the IceBridge science team had a rare opportunity to collect data over glaciers on the east side of the northern Antarctic Peninsula that normally are enshrouded by clouds.

After a final weekend of data-collection flights, the DC-8 and the IceBridge team are scheduled to return home Nov. 22 to the airborne science laboratory's base at the Dryden Aircraft Operations Facility in Palmdale, Calif. The Gulfstream returned to the United States earlier this month.

This story was provided by OurAmazingPlanet , a sister site to LiveScience.

Tsunami Hits Japan After Massive 8.9 Earthquake

Update 5:00 p.m. EST:

Much of the harbor in Crescent City, California, has been destroyed, and one person is feared dead, according to the Los Angeles Times. In Chile, officials have upgraded a tsunami warning to an alert and ordered coastal residents to evacuate, CNN Chile reported.

Related Coverage

Update 3:05 p.m. EST:

The U.S. National Oceanic and Atmospheric Administration released a video showing how the tsunami has spread. Crescent City, California, has been hit hard, with reports of waves up to 6 feet (1.8 meters) tall.

Update 2:42 p.m. EST:

A magnitude 6.2 earthquake has struck off the west coast of Honshu, but it's not clear yet if it's related to the 8.9 magnitude quake. There have been about 100 aftershocks of magnitude 5 or greater since the mainshock, according to the USGS. At a press conference, scientists said the entire island of Honshu moved eastward by 8 feet (2.3 m).

Update 1:10 p.m. EST:

In Hawaii, the Pacific Tsunami Warning Center hase lifted the evacuation order. Waves have reached northern California, with heights of 2.5 feet (0.7 meters) at Point Arena, 1.6 feet (0.5 m) at San Francisco and 2.4 feet (0.7 m) at Monterey.

Update 11:55 a.m. EST:

In Hawaii, the Pacific Tsunami Warning Center is reporting waves of 4.6 feet (1.5 meters) in Hilo, Big Island, 5.7 feet (1.7 m) in Kahului, Maui, and 2.3 feet (0.7 m) in Honolulu. Australia, Mexico, Central and South America are also under a tsunami warning

Update 11:30 a.m. EST:

The latest death toll is now at 137, with 531 reported missing, according to the Kyodo News Agency, citing police. Additionally, 200 to 300 bodies have been found in coastal Sendai, CNN reported. In the United States, tsunami waves are being reported near the California-Oregon border, in Port Orford, Oregon, and Crescent City, California.

Update 10:40 a.m. EST:

Japan's Kyodo News Service, citing Japan's defense forces, said 60,000 to 70,000 people were being evacuated to shelters in the Sendai area. In Hawaii, waves up to 7 feet (2 meters) high hit near Maui. The waves are rolling in every 15 minutes. No major damage has been reported in the two hours since the first waves hit.

Below is our original news story, which remains as originally posted:

Editor's Note: This story was updated at 9:25 a.m. EST.

An 8.9-magnitude earthquake struck northern Japan today (March 11), triggering tsunamis across the area that reportedly swept cars, buildings and other debris well inland.

The epicenter of the March 11 earthquake occurred near the east coast of Honshu, Japan.
The epicenter of the March 11 earthquake occurred near the east coast of Honshu, Japan.

Credit: USGS

The epicenter of the earthquake was 231 miles (373 kilometers) northeast of Tokyo and 80 miles (130 km) east of Sendai, Honshu, according to the U.S. Geological Survey.

A tsunami is a series of waves where the first one may not be the largest; wave heights can't be predicted and can change as the water hits the coast, according to the USGS.

The March 11 earthquake was preceded by a series of large foreshocks over the last two days — the first of which was a 7.2-magnitude quake on March 9 about 25 miles (40 km) from the March 11 earthquake. Today's temblor occurred as a result of thrust-faulting on or near the subduction zone, where Earth's Pacific plate thrusts underneath Japan at the Japan Trench.  

The Japan Meteorological Society has forecast more major tsunamis in the area, with some expected to reach more than 30 feet (10 m) off the coast of Hokkaido, Japan's second largest island. A tsunami was also generated off the coast of Hawaii, one that could cause damage along the coastlines of all islands in the state of Hawaii, according to the Pacific Tsunami Warning Center. Tsunami warnings are in effect across Hawaii as well.

A Tsunami Warning is also in effect for:

  • Coastal areas of California and Oregon from Point Concepcion, Calif., to the Oregon-Washington border.
  • Coastal areas of Alaska from Amchitka Pass, Alaska (125 miles west of Adak) to Attu, Alaska.

(A Tsunami Warning is the highest tsunami alert and means a tsunami is imminent. All coastal residents in the warning area who are near the beach or in low-lying regions should move immediately inland to higher ground and away from all harbors and inlets including those sheltered directly from the sea.)

A Tsunami Advisory is in effect for:

  • Coastal areas of California from the California-Mexico border to Point Concepcion, Calif.
  • Coastal areas of Washington, British Columbia and Alaska from the Oregon-Washington border to Amchitka Pass, Alaska.

(A Tsunami Advisory is the third highest tsunami alert and means that a tsunami capable of producing strong currents or waves dangerous to people near water is expected.)

As for why some earthquakes trigger tsunamis and others don't, scientists say several factors come into play, including the strength of the quake (below 7.5- or 7.0-magnitude quakes don't typically cause tsnamis), the direction of the temblor's motion and the topography of the seafloor, according to the USGS.

Apocalyptic Midwest Quake Predictions Overblown, Scientists Now Say

Fears of the next big earthquake in America’s heartland are just a bunch of hype.

That’s according to a new book that explains how there’s little scientific evidence to back up the apocalyptic predictions that a set of faults in the Midwest that set off huge quakes a couple centuries ago, known as the New Madrid Seismic Zone, could rupture violently again soon.

In “Disaster Deferred: How New Science Is Changing Our View of Earthquake Hazards in the Midwest”(Columbia University Press, October 2010), author and geologist Seth Stein tries to reassure folks living near the infamous New Madrid faults by explaining the science behind earthquakes in the middle of the continent.

Stein, of Northwestern University in Evanston, Ill., said there’s little scientific evidence for the fear of “the next big one” in the New Madrid seismic zone the site of some of the strongest earthquakes ever recorded in the continental United States, nearly 200 years ago.

Scare tactics

In 1990, a widely touted prediction said a big quake would hit the area, and a media circus ensued. The prediction proved false but highlighted the fear and hype surrounding the idea of a big Midwestern earthquake, Stein says.

As the 200th anniversary of the earthquakes that occurred in the area of New Madrid, Mo., approaches, talk of catastrophe is rising again.

“It’s said that the 1811 and 1812 earthquakes were the biggest in U.S. history, which isn’t true,” Stein said. “Or that they rang church bells in Boston, which isn’t true. And that another huge earthquake is on the way, which there’s no reason to believe.”

The findings detailed in “Disaster Deferred” come from more than 20 years of research regarding the New Madrid seismic zone. The book describes Stein’s scientific adventures that ultimately found no sign that large earthquakes will hit the New Madrid area within the next several hundred or even thousands of years.

“We, of course, can’t say there will never be another New Madrid earthquake like the ones in 1811 and 1812, but there’s no sign of one coming. The next could be thousands of years or tens of thousands of years in the future,” Stein said.

Remaining Risk

The seismic zone today generates about 200 tiny quakes annually, but it also let loose a magnitude 4.1 quake in February 2005 and a magnitude 4.0 quake in June 2005. An estimate from the 1980s asserted a 9-in-10 chance of a magnitude 6 or 7 temblor occurring in this area within the next 50 years. Later estimates have reduced this probability somewhat, although there is no consensus among researchers.

The Mississippi River is somewhat to blame for the 1811 and 1812 quakes, according to a study released earlier this year. Sediment erosion from the river released a great weight off the fault, allowing the Earth to buckle and the faults to rupture. That study also suggests that an earthquake is unlikely to hit anytime soon on the same faults in New Madrid.

Some seismic risk remains, however. A 2007 study discovered that an ancient, giant slab of Earth called the Farallon slab that started its descent under the West Coast 70 million years ago is causing mayhem and deep mantle flow 360 miles (579 kilometers) beneath the Mississippi Valley where it effectively pulls the crust down nearly half a mile (1 km).

The Farallon plate will continue to descend into the deep mantle and thus cause mantle downwelling in the New Madrid region for a long time, suggesting there will be seismic risk in the New Madrid region that will not fade with time, the authors of that study said.

Mavericks Competition: Why Surf Spot Has Monster Waves

Right now, the world's best surfers are riding the monster waves at Titans of Mavericks, an elite surf competition that pits big-wave riders against the monster swells at a Northern California Beach.

The competition happens every year in the winter at Pillar Point in Half Moon Bay, California, at a time when the waves and weather align. When the forecast looks good, surfers have just 48 hours to make it to the competition. In 2015, the comeptition wasn't called because the huge swells never showed up.

Waves this year were slated to reach 50 feet (15 meters) tall, with winds of 46 to 75 mph (40 to 65 knots), Surfline reported

But just why do the waves get so big at this particular time and spot? [In Photos: Famous Surf Spots Around the World]

Winter storms thousands of miles away over the Pacific Ocean near Alaska provide the energy. There, a low-pressure front from the north collides with a high-pressure front from the south. The resulting pressure differential generates strong, fast winds that blow over a vast area of ocean for long periods of time. This wind energy then transfers to the ocean, where it creates big swells.

The tides also play a role in Mavericks' monster waves. During the transition from high to low tide, wave energy roiling the ocean reaches the seafloor. This energy has nowhere to go but up, increasing the wave's height, according to Bay Nature, a San Francisco-area magazine.

But the real magic comes from Half Moon Bay's bizarre geometry. After all, the beaches nearby don't get the same massive waves. The crests at Pillar Point, by contrast, can get so big that they register on seismographs miles away.

In 2007, researchers from California State University at Monterey Bay and the National Oceanic and Atmospheric Administration used sound waves to create contour maps of the ocean floor near the competition. These maps show a ramp that rises sharply, but drops off steeply on either side, creating what the surfers call a launching pad.

When waves come from the right direction, the big ones touch the ocean floor and slow down, then curve into a "v" that focuses the wave's energy. With its energy focused, the wave quickly jumps in height, and the Big Kahuna is born, KQED's Quest reported.

Follow Tia Ghose on Twitterand Google+. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.

Climate Change May Increase Volcanic Eruptions

The rapid rise in sea levels could cause a dramatic increase in volcanic eruptions, according to a new study.

The study, published in the journal Geology, found that during periods of rapid climate change over the last million years, the rapid melting of continental glaciers and the resulting sea-level rise eventually increased volcanic eruptions as much as fold.

"Everybody knows that volcanoes have an impact on climate," said study co-author Marion Jegen, a geophysicist at Geomar in Germany. "What we found was just the opposite."

The findings were based only on natural changes in climate, so it's not clear whether human-caused climate change would have the same impact, Jegen said. And if it did, she added, the effect wouldn't be seen for centuries.

Volcanic changes

It's long been known that volcanism can dramatically alter the climate, often in cataclysmic ways. For instance, mass extinctions such as the one at the end of the Permian period may have been caused by continuous volcanic eruptions that cooled the climate and poisoned the atmosphere and the seas. [50 Amazing Volcano Facts]

But few people thought climate change could fuel volcanic eruptions before Jegen and her colleagues began looking at cores drilled from the oceans off of South and Central America. The sediments showed the last 1 million years of Earth's climatic history.

Every so often, shifts in Earth's orbit lead to rapid warming of the planet, massive melting of glaciers and a quick rise in sea levels. The team found that much more tephra, or layers of volcanic ash, appeared in the sediment cores after those periods. Some places, such as Costa Rica, saw five to 10 times as much volcanic activity during periods of glacial melting as at other times, Jegen told LiveScience.

To understand why that would be, the research team used a computer model and captured how those changes affected the pressures experienced at different places on the Earth's crust. The team found that when glaciers melt, they reduce the pressure on continents, while sea-level rise increases pressures on the ocean floor crust. In the computer model, the change in pressures on the Earth's crust seem to cause increases in volcanism.

In general, the speed of the transition from ice age to melting, rather than the total amount of melting, predicted how intensely the volcanic eruptions increased, she said.

The study doesn't address whether modern-day climate change would have any impact on the frequency of volcanic eruptions, though in theory it's possible, Jegen said.

But even if anthropogenic, or human-caused, climate change impacts volcanic eruptions, people wouldn't see the effect in this lifetime, because the volcanic activity doesn't occur immediately after the climate change, Jegen said.

"We predict there's a time lag of about 2,500 years," Jegen said. "So even if we change the climate, you wouldn't really expect anything to happen in the next few thousand years."

Follow LiveScience on Twitter @livescience. We're also on Facebook & Google+

Chilling Photos Show Coral Bleaching Across The Globe

Corals are dying across the planet. The culprit? Ever-increasing temperatures are stressing out corals' colorful partners called zooxanthellae. The result? Bleached-white corals. Now, scientists with the National Oceanic and Atmospheric Administration (NOAA) have found the stressful conditions are expanding from Hawaii into the Caribbean. Because of the breadth and severity of the bleaching, NOAA scientists have declared a "global coral bleaching event," only the third such declaration on record. Here's a look at what's happening beneath the world's seas.

Before and after

This before-and-after image shows the corals in American Samoa, in the South Pacific Ocean, before (image taken in December 2014) and after the bleaching event (image taken in February 2015). Corals get their rainbow hues from the microscopic algae called zooxanthellae that live in their tissues and photosynthesize to produce food for the corals. In return, the algae have a snug place to live … that is unless conditions in the water become inhospitable and they die off. (Photo Credit: XL Catlin Seaview Survey)

Seeing white

Alice Lawrence, a marine biologist, assesses the bleaching at Airport Reef in American Samoa in February 2015. (Photo Credit: XL Catlin Seaview Survey)

Coral graveyard

A researcher with the XL Catlin Seaview Survey photographs a severely bleached coral in Kaneohe Bay, Hawaii, in October 2014. The photos will be uploaded into Google Street View. (Photo Credit: XL Catlin Seaview Survey)

Hawaii event

During the first mass-bleaching event in the main islands of Hawaii, a researcher with the XL Catlin Seaview Survey assesses the level of bleaching in October 2014.

Stark staghorn

Bleached staghorn coral seen in this close-up image taken in February 2015 in American Samoa. Scientists think there are hundreds of species of the branching stony coral called staghorn; these reef builders take various colors and shapes "from flat platelike colonies to pillowlike clumps to the branching, antlerlike form," according to the Monterey Bay Aquarium. (Photo Credit: XL Catlin Seaview Survey)

Fire's out

A scientist records a bleached fire coral in Bermuda. (Photo Credit: XL Catlin Seaview Survey)

Orange and white

 

A fire coral in Bermuda: The one on the left is a healthy fire coral, while the one on the right is completely bleached. (Photo Credit: XL Catlin Seaview Survey)

Transparent skeleton

The white skeleton of a coral that lost its colorful zooxanthellae during a bleaching event in American Samoa. Like other reef-building corals, this one is not a single organism but rather a colony of hundreds to hundreds of thousands of tiny animals called polyps. Each teensy polyp has a stomach that opens at one end (the mouth), which is encircled with tentacles. (Photo Credit: XL Catlin Seaview Survey)

Worst 'outbreak'

A completely bleached coral photographed by the XL Catlin Seaview Survey in Hawaii during the main islands' first mass-bleaching event in late 2014. (Photo Credit: XL Catlin Seaview Survey)

Kaneohe 'bones'

Bleached corals dot the floor of the famous Kaneohe Bay in Hawaii, along the coast of the Island of O'ahu, as seen in this image taken by the XL Catlin Seaview Survey. (Photo Credit: XL Catlin Seaview Survey)

Bad fish housing

As seen in early 2015, a reef in American Samoa turns drab during a bleaching event in which about 80 percent of this reef's corals died. Not all corals build reefs, but those that do start with free-swimming larvae. These little baby corals attached to a hard surface along the edges of islands or submerged rocks. As the colonial organism grows and expands, a reef is born. (Photo Credit: XL Catlin Seaview Survey)

Turtle love

A green turtle swims through a bleached reef in Hawaii, as seen in late 2014 during an XL Catlin Seaview Survey. "Coral reefs are among the most biologically diverse ecosystems on Earth," according to the Sea Turtle Conservancy. (Photo Credit: XL Catlin Seaview Survey)

Fish food?

A long-nose file fish — an iconic reef fish — struggles to find coral polys to eat. File fish are completely reliant on healthy corals for food. (Photo Credit: XL Catlin Seaview Survey)

Follow Jeanna Bryner on Twitter and Google+. Follow us @livescience, Facebook & Google+

What's Causing So Many Earthquakes In Oklahoma?

A magnitude-4.2 earthquake hit just outside Edmond, Oklahoma, last night (Aug. 2) at 9:56 p.m. local time — the fifth significant temblor to shake this region of the state already this month, according to the U.S. Geological Survey.

The temblor originated at a depth of 1.9 miles (3 km), about 15 miles (24 km) northeast of Oklahoma City, the USGS said. According to the Edmond police department's Twitter account, as of last night, no significant damage had been reported. News 9 in Oklahoma City reported that although 4,600 people were left without power after the quake, all power has since been restored. [The 10 Biggest Earthquakes in History]

But last night's quake is part of a recent trend. Since Tuesday (Aug. 1), five earthquakes above magnitude 3.0 have been reported in this region, Xiaowei Chen, assistant professor of geophysics at the University of Oklahoma, told Live Science. It appears to be part of a longer sequence of earthquakes that began in 2014, she added. In fact, in 2014, the USGS issued an earthquake warning in the central part of the state — the first time the agency had ever issued such a warning for a state east of the Rockies.

Chen didn't yet know enough about the most recent earthquake sequence to be able to comment on whether this recent magnitude-4.2 earthquake may signal that an even bigger earthquake will come, or if it's simply within the range of expected seismic activity in the area, she said.

Although it's difficult to attribute earthquakes to a particular cause, it's possible that human activity induced this earthquake, William Yeck, a research geophysicist with the USGS Geologic Hazards Science Center, told Live Science. Since 2014, there has been a significant increase in the rate of earthquakes in north central Oklahoma, the area in which this recent earthquake occurred, he said.  The cause of this increase? The injection of wastewater — a byproduct of oil and gas production — into the ground may be to blame.

"The injection of fluids underground can increase underground pressures," he said. "This, in turn, can effectively unclamp faults, allowing them to slip, which results in earthquakes."

Last year, scientists reported that north central Oklahoma and the southernmost part of Kansas were at the greatest risk of a human-induced earthquake in the United States.

The high rate of earthquakes that began in 2014 began to drop off last year, which Yeck thinks may be due to the decrease in wastewater injection in this area.

"I just stress that [for] people [living] in an area that's prone to earthquakes, preparedness is key," he added.  

Original article on Live Science.

Where's The Snow?

Maps of the nation's snow cover show a lot less white stuff covering the country right now compared with this time last year.

In mid-December last year, the Deep South was reeling from an unusually big snowfall. Today, snow is scarce anywhere on the East Coast or in the Midwest. Instead, the powder is falling out West, where Arizona has been transformed into a winter wonderland.

The lack of big snow has folks scratching their heads in the Midwest.

"Everybody's talking about," said Wayne Hoepner, a meteorologist with National Weather Service in Grand Rapids, Mich., where this year's forecast calls for more snow than normal. [Images: Snow from Space]

Last year on Dec. 14, 2010, the snow cover was a different story.
Last year on Dec. 14, 2010, the snow cover was a different story.

Credit: NOHRSC/NOAA

Year-to-year

This time last year, lake-effect snow in the Northeast and Midwest was falling hard. The snow was so bad in Buffalo, N.Y., even the snowplows got stuck. Several feet of snow fell in western New York and in cities around the Great Lakes. That hasn't happened yet this year.

"We haven't really had any cold weather or cold air moving over the lake," Hoepner told OurAmazingPlanet. "We're a little concerned that we haven't had much yet, but not all that concerned."

Lake-effect snow is created when bitter Arctic air spills south over the warmer Great Lakes. The cold air warms, moistens and forms into snow clouds, which drop the white stuff in whichever direction the strongest wind is blowing. Lake-effect snow is heaviest downwind, or leeward, of a water body.

Snowy surprises

Even though the ground in much of the country is bare, as seen in the National Snow and Ice Data Center's map of snow depth, the 2011 winter has already given a few fleeting surprises.

A surprisingly early snowstorm smacked the East Coast on Halloween, knocking out power to thousands in Connecticut. New York’s Central Park recorded 2.9 inches of snow (7.6 centimeters), the first time since record-keeping began in 1869 that an inch or more of snow has been recorded there during the month of October, according to the NWS.

A week before, that same weather system created wild weather in Denver. The Colorado capital saw temperatures of 80 degrees Fahrenheit (27 degrees Celsius) on Oct. 24, a record for the day in Denver. Snow and freezing temperatures came in with the winter system the next day.

It wasn't much, but on Nov. 28, Alabama saw a November snowfall for the first time in 35 years. From Memphis, Tenn., to Atlanta, a rare snow coated cities that day as the temperatures dropped sharply due to a "cold bubble" that formed over the South.

In early December, a light snow fell on north Texas, with heavier snow blanketing much of New Mexico. Interstate 25 was snow-packed in New Mexico, and severe wind created blizzard and whiteout conditions.

At least one predictably snowy region is getting their fair share this year. Today (Dec. 14), more than a foot of snow fell in Flagstaff, Ariz., according to the NWS.

"Nothing unusual at all," David Blanchard, a meteorologist with the NWS in Flagstaff, said. "We get heavy snow here every winter."

A low-pressure system moved through the region, which is 7,000 feet (2,100 meters) above sea level, and drew in moisture from the south. Nearly 3 feet (1 m) of snow has fallen in the highest elevations.

You can follow OurAmazingPlanet staff writer Brett Israel on Twitter: @btisrael. Follow OurAmazingPlanet for the latest in Earth science and exploration news on Twitter @OAPlanet and on Facebook.

Trapping Carbon Dioxide Underground: Can We Do It?

In a policy address last week, President Barack Obama made the reduction of greenhouse gas emissions in the United States a key priority in the nation's fight against climate change. Now, a newly released geological report points to a promising way to cut down on the amount of harmful carbon dioxide pumped into the atmosphere: inject and store it inside rocks deep underground.

The U.S. Geological Survey (USGS) conducted a detailed assessment and found 36 regions across the country that have the proper subterranean conditions to store between 2,400 to 3,700 metric gigatons of carbon dioxide underground — a process known as geologic carbon sequestration. One metric gigaton is equal to a billion metric tons.

In a separate report released in early June, the U.S. Energy Information Administration, an organization that collects and analyzes statistics on energy production and consumption, projects the United States will emit approximately 5.4 metric gigatons of fossil fuel-related carbon dioxide in 2013, which includes coal, natural gas and petroleum emissions. Based on these estimates, the USGS findings represent a vast, untapped resource that could help reduce carbon dioxide emissions and mitigate the impact they have on Earth’s climate, said Briana Mordick, a geologist at the Natural Resources Defense Council (NRDC), a nonprofit environmental advocacy group headquartered in New York City.

"This is just one tool in a range of options that we have, but it's an important one to give us additional time to transition from fossil fuels to nonfossil fuel energy," Mordick told LiveScience. [The Reality of Climate Change: 10 Myths Busted]

As part of its survey, the USGS excluded areas of the country that are considered freshwater sources, and limited their assessment to rock layers at depths at which the carbon dioxide would be under sufficient pressure to remain in a liquid state, which would help the carbon dioxide mix in with the briny water found underground.

The study identified the largest storage potential in the Coastal Plains region, which encompasses much of the Gulf Coast. This area could account for roughly 2,000 metric gigatons, or 65 percent, of the country's storage potential, according to the USGS report. Other areas with considerable storage capacity include the Alaska region and the Rocky Mountains.

Going beneath the surface

Geologic carbon sequestration involves capturing the exhaust gases from power plants before they are released into the atmosphere, and separating the carbon dioxide from the rest of the emissions. This carbon dioxide is then cooled and compressed into a so-called supercritical state, which means it has properties between a liquid and a gas, Mordick explained.

Next, the supercritical carbon dioxide travels through a network of underground pipelines to a site where it is pumped through a well into subsurface rocks.

"The idea is that the carbon dioxide will be trapped there pretty much indefinitely," Mordick said. "Things like oil, gas and brine are trapped in the subsurface for millions of years, so basic geologic principles tell us this is possible. In some ways, it's mimicking natural geologic processes."

To do this, the carbon dioxide needs to be injected deep underground, between at least 3,000 and 15,000 feet (914 and 4,600 meters), said Peter Warwick, chief of the geologic carbon sequestration project at the USGS, which put out the sequestration report. In addition, certain types of rocks are more suited to hold carbon dioxide. [Video: How Carbon Capture & Sequestration Works]

"You want a rock that has what we call porosity, which means there are small, open areas within the rock, and permeability, which is the ability for fluid to move through the rock," Warwick said.

Sandstone or limestone rock formations are particularly good storage reservoirs, but equally important are the layers of rock over the top that act as a cap, sealing in the carbon dioxide, Mordick said. Without this robust rock layer, carbon dioxide could seep out and leak to the surface, reaching the atmosphere anyway.

"There has to be a good ceiling formation above — something like shale, with low porosity and low permeability," Mordick said. "Essentially, it's like a lid on top of the storage formation that prevents carbon dioxide from migrating vertically."

Leaks are one of the primary concerns surrounding geologic carbon sequestration, and researchers around the country are assessing the risks involved, which includes studying the types of conditions that could cause carbon dioxide to escape.

Trapped underground

One possible way the gas could escape is by seeping into a shallower rock formation, where it might then spread and eventually make its way to the surface, said Ronald Falta, a professor in the Department of Environmental Engineering and Earth Sciences at Clemson University in Clemson, S.C.

In 2009, Falta and a colleague, Larry Murdoch, received an $891,000 grant from the Environmental Protection Agency (EPA) to research how to safely store carbon dioxide in geological formations. The project, which also involves Sally Benson, director of Stanford University's Global Climate & Energy Project, is in its final year.

Falta said that while leaky carbon dioxide is a major concern, the idea of storing material in subsurface rocks is a well-understood process.

"People have been storing natural gas in underground formations for years with very few problems," Falta said. "If these sites are studied carefully, and if they're deep enough, I think the risk is low. But, it's still a major issue that we're going to have to address before anything is done, while the carbon dioxide is being injected, and after it's injected. We need to think: How do we safeguard against leaks, and what are we going to do if it does?"

Geologic carbon sequestration is currently regulated by the EPA, under its Class VI rules for injection wells. Under these rules, companies or organizations are required to monitor the site for leaks for at least 50 years after the injection process.

Mordick, at the NRDC, said the Class VI guidelines are the most stringent rules the EPA has written, and they are designed to regulate the entire sequestration process, from the selection of the storage site to the decades following.

Falta said that over time, different trapping mechanisms will naturally help contain the carbon dioxide (CO2), but monitoring how the carbon dioxide initially moves through the limestone or sandstone rocks will be critical. 

"Carbon dioxide dissolves in water under those high pressures, so eventually it's all going to dissolve and not have a tendency to rise," he explained. "Over longer periods, it will turn into minerals and carbonates, so it's mostly in the early periods, when you have a buoyant plume of CO2, that you have to be really careful."

Follow the money

The USGS report did not evaluate the economic viability of geologic carbon sequestration, but the cost of deploying these types of capture and storage technologies could be one of the main barriers to actually employing this strategy. For one, extracting carbon dioxide from power plant emissions is a costly process. [Top 10 Craziest Environmental Ideas]

"It's really expensive to separate the carbon dioxide from the flue gasses coming out of the power plants," Falta said. "That's where the major cost is going to be, and it has been done at small and medium scales, but not at the massive scales that we might be talking about for large power plants."

Warwick said the USGS intends to publish a follow-up report on the economics involved with geologic carbon sequestration, based on the results of their initial study.

"There is a significant buy-in, so all this development and infrastructure comes with a cost," Warwick said. "If you're willing to pay for the cost to capture CO2 and put it into the ground, then it could make a significant impact."

The USGS is also investigating other risks involved with injecting carbon dioxide deep underground, including whether this process could induce unwanted seismic activity, Warwick added. Injection of waste water from fracking, or hydraulic fracturing, has been linked to increased seismicity in areas where the injection occurs.

Still, geologic carbon sequestration represents an enticing way to reduce the nation's amount of greenhouse gas emissions, Falta said, and an opportunity to lessen the environmental impact of coal-fired power plants.

"The U.S. has more of these rock formations than any other country, and more than any other continent, so in that respect, we're kind of lucky," Falta said. "It will probably boil down to a question of economics. Will people think it's worth it to do this, or should we continue to use coal? And we have a lot of coal, too."

Follow Denise Chow on Twitter @denisechow. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.com.