Magnitude 6.1 Earthquake Near Adak, Tsunami Not Expected

A magnitude 6.1 earthquake struck 57 miles southwest of Adak, Alaska, at 9:47 Saturday morning. At this time, a tsunami is not expected, according to the National Weather Service Tsunami Warning Center.

The earthquake epicenter was some 37 miles south of Bobrof island, just 62 miles deep. The area is in the far western Aleutians, some 1,200 miles southwest of Anchorage.

At this time there are no reports of damage.

Strong 6.8-Magnitude Earthquake Hits Western Brazil

A strong earthquake with a preliminary magnitude of 6.8 has struck Brazil’s Amazon region, but damage is unlikely because it struck at a depth of nearly 600 kilometers (372 miles), seismologists say.

The earthquake, which struck at 2:25 p.m. local time on Saturday, was centered in the Amazon rainforest, about 89 kilometers (55 miles) west of Tarauacá in Acre state, or 739 kilometers (459 miles) northeast of Lima.

The U.S. Geological Survey measured the magnitude at 6.8 but said it struck at a depth of 575 kilometers (479 miles), making it a very deep earthquake. Peru’s seismological agency put the magnitude significantly higher, at 7.2.

Damage is unlikely because it struck far below the surface and in a remote area. Computer models from the UN estimate that nearly 5,300 people live within 50 kilometers (31 miles) of the earthquake epicenter.

Saturday’s earthquake was the strongest to hit Brazil since 2003, when a powerful 7.1-magnitude earthquake hit the same region. However, strong and deep earthquakes sometimes hit Peru in areas that are close to the border with western Brazil. They rarely cause damage.

JUST IN: Researchers Find Deep Ocean Getting Colder

A pair of researchers, one with the Woods Hole Oceanographic Institution, the other Harvard University, has found evidence of deep ocean cooling that is likely due to the Little Ice Age. In their paper published in the journal Science, Jake Gebbie and Peter Huybers describe their study of Pacific Ocean temperatures over the past 150 years and what they found.

The model showed that the Pacific Ocean cooled over the course of the 20th century at depths of 1.8 to 2.6 kilometers. The amount is still not precise, but the researchers suggest it is most likely between 0.02 and 0.08° C. That cooling, the researchers suggest, is likely due to the Little Ice Age, which ran from approximately 1300 until approximately 1870. Prior to that, there was a time known as the Medieval Warm Period, which had caused the deep waters of the Pacific to warm just prior to the cooling it is now experiencing.

Prior research has suggested that it takes a very long time for water in the Pacific Ocean to circulate down to its lowest depths. This is because it is replenished only from the south, which means it takes a very long time for water on the surface to make its way to the bottom – perhaps as long as several hundred years. That is what Gebbie and Huber found back in 2012. That got them to thinking that water temperature at the bottom of the Pacific could offer a hint of what surface temperatures were like hundreds of years ago.

To find out if that truly was the case, the researchers obtained data from an international consortium called the Argo Program – a group of people who together have been taking ocean measurements down to depths of approximately two kilometers. As a comparative reference, the researchers also obtained data gathered by the crew of the HMS Challenger – they had taken Pacific Ocean temperatures down to a depth of two kilometers during the years 1872 to 1876. The researchers used the data from both projects to build a computer model meant to mimic the circulation of water in the Pacific Ocean over the past century and a half.

No Tsunami Threat To Hawaii From Alaska Earthquake

The Pacific Tsunami Warning Center said a magnitude 6.1 earthquake that struck Alaska today poses no local threat of a tsunami.

 

A earthquake magnitude 6.1 (ml/mb) has struck on Sunday, 116 km SE of Cold Bay, Alaska (72 miles). Exact location, longitude -161.4719° West, latitude 54.4279° North, depth = 26.92 km.

The 6.1-magnitude earthquake has occurred at 15:35:37 / 3:35 pm (local time epicenter). A tsunami warning has been issued near Cold Bay in Alaska (Does not indicate if a tsunami actually did or will exist).

Bali Volcano Shoots New Burst Of Ash; Flights Unaffected

A volcano on Indonesia’s tourist island of Bali shot a new burst of hot ash into the air early Sunday in the latest of the country’s several eruptions within a week.

Mount Agung erupted for about three minutes, spewing white clouds of smoke and ash more than 700 meters (2,300 feet) into the air, the Volcanology and Geological Mitigation Agency said in a statement.

The eruption of the 3,031-meter (9,940-foot) volcano didn’t prompt evacuations, and its alert status remains at the second-highest level. The agency warned tourists to stay away from the danger zone in a 4-kilometer (2.5-mile) radius around the crater.

Agency spokesman Sutopo Purwo Nugroho said that white dust from the eruption blanketed several villages close to the mountain slope in Karangasem district.

Ngurah Rai International Airport spokesman Arie Ahsanurrohim said that flights were operating normally. Authorities said the air around Denpasar, the Bali provincial capital, is clear from ash.

More than 140,000 people had fled the area around the mountain in late September after its alert status was raised to the highest level, indicating an eruption may be imminent. The alert status was lowered two weeks later, allowing for the return of those displaced from government shelters.

An eruption in 1963 killed about 1,100 people. Agung lies about 70 kilometers (45 miles) northeast of Bali’s tourist hotspot of Kuta.

It is among more than 120 active volcanoes in Indonesia, which is prone to volcanic eruptions and earthquakes because of its location on the so-called “Ring of Fire” — a series of fault lines stretching from the Western Hemisphere through Japan and Southeast Asia.

Last week, Anak Krakatau in Indonesia’s Sunda Straits erupted and collapsed into the sea, causing a tsunami that killed 431 people on Java and Sumatra. More than 46,600 were displaced.

Indonesian Volcano That Triggered Tsunami Loses Two-Thirds Of Its Height

Anak Krakatoa, the Indonesia volcano that triggered a deadly tsunami a week ago, has lost two-thirds of its height, a government agency said.

The volcano’s height went from 338 meters (1,108 feet) above sea level to 110 meters (360 feet), Indonesia’s Center of Volcanology and Geological Hazard Mitigation said in a report.

Additional eruptions from Monday to Thursday also caused the volcano to lose volume of 150 million to 180 million cubic meters (5.3 billion to 6.4 billion cubic feet), the report said. Its volume is now 40 million to 70 million cubic meters (1.4 billion to 2.5 billion cubic feet).

The December 22 tsunami was triggered by a volcanic eruption that caused a 64-hectare (158-acre) chunk of Anak Krakatau to slide into the ocean.

Government and rescue agencies cited multiple factors in the wave that struck coasts on the islands of Java and Sumatra. The eruption came at high tide during a full moon, and the Sunda Strait, which runs between Java and Sumatra, also had been experiencing high rainfall.

On Saturday, Indonesia revised the number of people killed in last week’s tsunami to 426 people from an earlier toll of 430, citing duplications in government recording.

At a press briefing Friday, Sutopo Purwo Nugroho, a spokesman at Indonesia’s disaster management agency, said 7,202 people had been injured, 29 people remained missing and 43,386 had been displaced.

Officials said this week that sensors had been placed near Anak Krakatau for better detection of activity within the volcano in hopes of providing a warning about eruptions.

Indonesian authorities have been roundly criticized for the state of the country’s tsunami detection and warning system, which has been largely out of action since at least 2012.

The alert level for the volcano remains at its second-highest — Level 3. Tremors continue and a pyroclastic flow, a mix of ash, rock and volcanic gases, runs 2 kilometers (1.2 miles) from the crater. Pyroclastic flow can be much more dangerous than lava.

More than half the population have been evacuated on Sebesi and Sebuku islands near Anak Krakatau in the Sunda Strait.

Earthquake Off Philippine Coast Hits A Region Already On High Alert

An undersea earthquake occurred Saturday off the coast of the southern Philippines. The U.S. Geological Survey says it struck at a depth of about 38 miles and had a magnitude of 7.0. According to The Associated Press, no casualties or damage had been reported as of a few hours after the quake.

It was felt in several cities in the southern Philippines and led the Pacific Tsunami Warning Center to issue a tsunami threat – which has since been lifted — for areas along the coasts of Indonesia and the Philippines.

This most recent scare, which seemed to cause little damage, is the latest seismic activity in a region reeling from disaster. On Dec. 22, a tsunami hit Indonesia and killed at least 430 people. NPR’s Anthony Kuhn reported that Indonesia’s seismic activity directors were faulty, which meant that residents were not properly warned. Kuhn also noted that Indonesians did not feel an earthquake, a common warning sign, before the tsunami struck.

A widely shared video of a concert is one of the more unsettling illustrations of how unexpected the disaster was: The local pop-rock band Seventeen was performing at a party in Java one moment and taken by a massive wave the next.

Now scientists might know why last Saturday’s disaster happened. According to a statement from the European Geosciences Union, the partial collapse of Anak Krakatau, a volcano in Indonesia’s Sunda Strait, may have caused the tsunami. Researcher Raphaël Paris says Anak Krakatau’s instability will continue to pose a risk. In the EGU statement, Paris says, “There is a big uncertainty on the stability of the volcanic cone now and the probability for future collapses and tsunamis is perhaps non-negligible.”

When Anak Krakatau lost a 64-hectare portion of its west-southwest flank, tons of rocky debris fell into the sea and brought forth powerful waves. This, according to the BBC’s Jonathan Amos, could have been the source. NPR’s Julie McCarthy reports that researchers say the volcanic cone has decreased in height from 1,108 feet to just 336 feet. Satellite images also show a significant decrease in Anak Krakatau’s size.

Paris was part of a team that modeled a very similar Anak Krakatau-induced tsunami back in 2012. Mike Burton, president of the EGU Division on Geochemistry, Mineralogy, Petrology and Volcanology, said in the EGU’s statement: “The hazard scenario were therefore understood, but the management of such a hazard obviously remains a major challenge.”

The exact details of the tsunami’s cause — the nature of the eruption that triggered the loss of the flank, for example — will not be determined until researchers can access the area of the volcano, according to the BBC’s Amos.

Anak Krakatau translates to “child of Krakatau.” Anak’s parent, Krakatau (or Krakatoa), is perhaps best known for exploding in 1883. According to Hawaii Public Radio’s Neal Conan, about 100,000 people died from that eruption’s direct effects and more than 35,000 others died from resulting tsunami waves. Anak Krakatau was formed from what remained of Krakatau.

Less than three months ago, another tsunami in Indonesia killed at least 1,400 others. And in August, a 6.9 magnitude earthquake killed at least 460. A statement issued in October by Indonesia’s National Agency for Disaster Management said 1,999 natural disasters occurred in Indonesia in 2018, leaving 3,548 dead or missing.