Europe’s Most Active Volcano Is Sliding Into The Sea

Perched on the northeastern edge of Sicily, Italy’s Mount Etna is a hyperactive volcano capable of producing incandescent lava flows as well as explosive, lightning-surrounded pyrotechnics. It’s also sliding into the Ionian Sea—and a new study provides fresh evidence as to why.

It’s been known for some time that the so-called Roof of the Mediterranean has been on the move. Etna is not slipping quickly; on average, its migration is happening at a rate several times slower than the growth rate of your fingernails. But geologists have been hunting for the exact cause of the volcano’s motion, since it’s linked to the risk that the fiery mountain may suffer a catastrophic collapse.

About a million people live on Etna’s slopes, and millions more reside on the coastlines across the Ionian sea. If part of the volcano near the shoreline becomes unstable and falls into the water, it could create mega-tsunamis that would devastate the shores of the eastern Mediterranean.

“A massive collapse would be a disaster for a vast and densely populated area,” says Boris Behncke, a volcanologist at the Etna Observatory at Italy’s National Institute of Geophysics and Volcanology who was not involved in the latest work. (Find out why people chose to live in the shadows of active volcanoes.)

Etna’s slippery slope
For their new study, published today in Science Advances, a team led by Morelia Urlaub at the Helmholtz Centre for Ocean Research in Kiel, Germany, deployed several underwater transponders around Etna’s southeastern flank, which they suspect is the most mobile section of the mountain.

These transponders contained pressure sensors that picked up on the slightest movements of the offshore flank. The devices also recorded their positions relative to each other, which meant that the team could detect movement of the flank compared to the more stable parts of the terrain.

According to the team, their results show that gravity is the primary force causing this flank of the volcano to move. Magma rising inside the volcano also plays a role, but the team thinks it has less of an overall effect on Etna’s seaward slide.

The new results “take us into the exciting realm of underwater monitoring for the first time at Etna,” says volcanologist John Murray of the U.K.’s Open University, who was not involved in the new work. Murray led a previous study that also looked at Etna’s slippage, and he says the new data are in line with his team’s observations, in that “magmatic forces are less important than gravitational spreading in the outward expansion of Etna.”

Until recently, many experts thought that shallow magma injections within the fiery mountain were the primary drivers of this volcano’s displacement. Indeed, during some of Etna’s eruptions, monitoring devices have recorded movements of tens of feet. This makes sense: Rising magma can inflate parts of the mountain, adding extra weight to sections of it and causing structural weaknesses to appear.

But Etna’s southeastern flank tends to slip in fits and bursts, and not all of that motion is linked to internal, molten turmoil.

Keeping a close eye on things between April 2016 and July 2017, the latest monitoring effort detected one case of major movement around mid-May of 2017, when the volcano’s flank jutted forward into the sea by an inch or two. This activity coincided with the eight-day movement of a local fault.

The team agrees that rising magma does play a role, because other flank accelerations match up nicely with unambiguous intrusions of new molten material. But the fact that such huge deformations are also occurring far from the magma-dominated summit suggests that gravity is the star of the show—a notion shared by other research groups.

In April, Murray’s team reported on their work using hundreds of onshore GPS kits to assess Etna’s movement. Their data indicated that, from 2001 to 2012, Etna moved toward the Ionian Sea in a southeasterly direction at a rate of 0.6 inches (about 14 millimeters) every year. These researchers also suspect that gravity is the driving force, pushing Etna along on a layer of loosely packed sediments.

Gravity will bring you down
The April study suggested that the entire volcano was moving, but the new paper only looked at the southeastern flank. Still, with both studies in mind, “it seems that the consensus is shifting toward gravitationally driven sliding as the dominant mechanism” for Etna’s movement, says Urlaub.

The new study’s interpretations are quite reasonable, Behncke says, although he adds that the situation is complex, and it’s likely that contributions from gravitational pulls and magmatic movements vary with time. Both factors are also connected, with gravitationally driven flank movements allowing magmatic intrusions to take place.

“It’s very difficult to make definitive statements unless the methods used by the authors are applied over a much longer period, encompassing a broader area,” he says.

There’s also the question of whether the southeastern flank movement could one day turn into a catastrophic collapse. Urlaub’s data indicates that it’s possible, although she notes that there’s not yet enough information to say for sure. Geologists need decades’ worth of monitoring data before they can tell the difference between normal and fast slippage.

There’s presently no sign of an imminent collapse on Etna’s slopes, but a lack of data on any similar incident means that there isn’t any way to tell when a major flank collapse might occur. No wonder, then, that Etna is one of the most heavily monitored volcanoes on Earth.

Guatemala Volcano Spews Ash Months After Deadly Eruption

Guatemala’s Volcano of Fire spewed ash and lava Saturday just months after an eruption killed at least 110 people.

The country’s seismology and volcanology institute said hot lava was spilling from the crater and flowing toward a ravine.

Constant rumblings from the volcano sounded like an engine, and columns of gray ash billowed 4,600 meters (15,091 feet) into the air.

Authorities urged nearby residents to evacuate and be alert for possible lahars – flows of mud, debris, water and pyroclastic material – that could be fed by afternoon rains.

The Volcano of Fire is one of the most active in Central America.

Dozens of people were buried alive or burned beyond recognition in June when the volcano expelled smoldering gas, ash and rock, catching residents off guard.

After Hurricane Michael: Shortages, Mourning, Darkness

Gas was in short supply, power outages were rampant and search teams continued their arduous tasks Sunday as Florida’s recovery from Hurricane Michael remained painfully slow along the coast of the state’s battered Panhandle.

There were some victories. Classes will resume Monday at Florida State’s sprawling, 40,000-student campus in Tallahassee and several other area universities. State offices also reopened.

In the Bay County communities of Panama City and Mexico Beach, where the strongest hurricane to hit the Panhandle since record-keeping began slammed onto the coast four days earlier, search-and-rescue crews accompanied by dogs solemnly picked through the rubble of shattered neighborhoods

The storm killed at least 17 people, including one in Mexico Beach. Entire communities were wiped out by the Category 4 storm’s roaring winds, and authorities feared the death toll would rise.

“If we lose only one life, to me, that’s going to be a miracle,” Mexico Beach Mayor Al Cathey said.

More than 170,000 power customers in Florida remained in the dark Sunday, including more than half the homes and businesses in Bay County. For some, power could be weeks away.

The effort to get schools and hospitals fully operational will be herculean. Bill Husfelt, superintendent of county schools, assessed damage over the weekend and had not decided when they could reopen.

“The superintendent wants everyone to know we are focusing on three things right now: faith, family and our future,” the district said in a Facebook post. “We will open our schools as soon as is feasible, but right now the county is focused on a humanitarian mission.”

Gulf Coast Medical Center in Panama City remained closed because of storm damage. Bay Medical Sacred Heart Hospital had “significant” damage that required evacuation of patients, CEO Scott Campbell said.

“Our hearts are heavy as we begin the process of rebuilding our community following the devastation of Hurricane Michael,” Campbell said.

A silver lining: Emergency rooms at both hospitals remained functioning.

Prison and jails were also hit hard. The state Department of Corrections said 2,600 inmates were evacuated from the Gulf Correctional Institution and Annex. An additional 305 were removed from Calhoun Correctional Institution.

No injuries were reported, and a website was provided for families to determine where their loved ones had been transferred.

“All inmates were secure and had access to food and drinking water through the duration of the storm,” the department said.

President Donald Trump is scheduled to visit the area Monday. The destruction he’ll encounters will be bleak.

“We’re all in this together,” Tallahassee Mayor and Democratic gubernatorial candidate Andrew Gillum tweeted Sunday. “Our office doors are open to collect supplies and donations for people in North Florida.”

Storm Leslie: Portugal Hit By Hurricane-Force Wwinds

Hurricane-force winds have struck central and northern Portugal, leaving 300,000 homes without power.

The remnants of Hurricane Leslie swept in overnight on Saturday, with winds gusting up to 176km/h (109mph).

Civil defence officials said 27 people suffered minor injuries, with localised flooding, hundreds of trees uprooted and a number of flights cancelled.

The storm, one of the most powerful to ever hit the country, is now passing over northern Spain.

The worst-affected areas in Portugal were around the capital, Lisbon, and in the districts of Coimbra and Leiria. Aveiro, Viseu and Porto in the north also suffered damage.

About 1,000 trees have been uprooted, officials say. The main A1 motorway was among the roads temporarily blocked.

Some 1,900 incidents were reported to emergency services, although civil defence commander Luis Belo Costa said “the greatest danger has passed”.

Hundreds of people remained in an arts centre in Figueira da Foz after a concert because of the high winds.

A resident of the town told SIC television: “I have never seen anything like it, The town seemed to be in a state of war, with cars smashed by fallen trees. People were very worried.”

The roof blew off a stadium hosting the European final of the women’s roller hockey competition, halting the event, AFP news agency reported.

It is rare for an Atlantic hurricane to reach the Iberian peninsula, with only five such events recorded.

Hurricane Leslie had formed on 23 September but was downgraded to a tropical storm before it made landfall. However, it retained gusts of hurricane strength.

The Spanish Meteorological Agency (Amet) said Leslie was moving north-east through the peninsula.

Gusts of almost 100km/h were recorded near the city of Zamora early on Sunday, but winds have now lessened.

Amet said that on Sunday morning large areas of Asturias, Castille and León and Cantabria would be affected, with north-eastern areas hit in the afternoon.

Four departments in southern France have also been put on alert for storms and flooding.

Papua New Guinea Hit by 7.0 Magnitude Earthquake

A magnitude 7.0 earthquake struck remote New Britain island in Papua New Guinea on Thursday, the United States Geological Survey said, though there were no immediate reports of damage.

The quake hit about 200 km (125 miles) southwest of the town of Rabaul at a depth of almost 40 km, just before 7 a.m. local time (2100 GMT Wednesday).

“We felt the earthquake a bit, but it was not too strong,” Constable Roy Michael told Reuters by phone from Rabaul police station.
He said there was no damage in the town, but officers had not yet been able to contact villages closer to the epicenter.

Scientists Develop A New Way To Remotely Measure Earth’s Magnetic Field

Researchers in Canada, the United States and Europe have developed a new way to remotely measure Earth’s magnetic field—by zapping a layer of sodium atoms floating 100 kilometres above the planet with lasers on the ground.

The technique, documented this week in Nature Communications, fills a gap between measurements made at the Earth’s surface and at much higher altitude by orbiting satellites.

“The magnetic field at this altitude in the atmosphere is strongly affected by physical processes such as solar storms and electric currents in the ionosphere,” says Paul Hickson an astrophysicist at the University of British Columbia (UBC) and author on the paper.

“Our technique not only measures magnetic field strength at an altitude that has traditionally been hidden, it has the side benefit of providing new information on space weather and atomic processes occurring in the region.”

Sodium atoms are continually deposited in the mesosphere by meteors that vaporize as they enter Earth’s atmosphere. Researchers at the European Southern Observatory (ESO), the University of Mainz and UBC used a ground-based laser to excite the layer of sodium atoms and monitor the light they emit in response.

“The excited sodium atoms wobble like spinning tops in the presence of a magnetic field,” explains Hickson. “We sense this as a periodic fluctuation in the light we’re monitoring, and can use that to determine the magnetic field strength.”

Hickson and UBC Ph.D. student Joschua Hellemeier developed the photon counting instrument used to measure the light coming back from the excited sodium atoms, and participated in observations conducted at astronomical observatories in La Palma.

The ESO team, led by Bonaccini Calia, pioneered world-leading laser technology for astronomical adaptive optics used in the experiment. Project lead Felipe Pedreros and Dmitry Budker (Johannes Gutenberg University), Simon Rochester and Ronald Holzloehner (ESO), experts in laser-atom interactions, led the theoretical interpretation and modeling for the study.

NASA Checks Out Hurricane Sergio’s Cloud Temperature

NASA’s Aqua satellite peered into Hurricane Sergio with infrared light to determine if the storm was intensifying or weakening. Infrared data showed cloud top temperatures were getting warmer on the western half of the storm, indicating the uplift of air in storms had weakened.

The Atmospheric Infrared Sounder or AIRS instrument aboard NASA’s Aqua satellite passed over Hurricane Sergio on Oct. 9 at 6:17 a.m. EDT (1017 UTC). AIRS uses infrared light and infrared light provides scientists with temperature data and that’s important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are. So infrared light as that gathered by the AIRS instrument can identify the strongest areas of a tropical cyclone.

At the time Aqua passed overhead, coldest cloud top temperatures in thunderstorms circled the eye and appeared in fragmented bands of thunderstorms north and south of the center. Those temperatures were as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). The exception was on the western side of the storm, where cloud top temperatures were warming, meaning they were not getting as high in the atmosphere.

Despite the slow weakening the hurricane still has a large but well-defined inner-core in the low and mid-levels.

The National Hurricane Center noted at 11 a.m. EDT (1500 UTC), the center of Hurricane Sergio was located near latitude 16.6 degrees north and longitude 127.4 degrees west. That’s 1,215 miles (1,960 km) west-southwest of the southern tip of Baja California, Mexico.

Sergio is moving toward the northeast near 7 mph (11 kph). A faster northeastward motion is expected for the next several days. Maximum sustained winds have decreased to near 80 mph (130 kph) with higher gusts. Gradual weakening is anticipated during the next several days.

NHC noted that there are no coastal watches or warnings in effect, but interests in Baja California Sur should monitor the progress of Sergio.