Earthquakes

Magnitude 5+ Earthquakes – Global

5.8 Earthquake hits offshore Valparaiso, Chile.

5.2 Earthquake hits Fiji.

5.0 Earthquake hits the Izu Islands off Japan.

5.0 Earthquake hits the Jan Mayen Island region.

Storms and Floods

Tropical Storms

In the Pacific:

Tropical storm Faxai is located approximately 380 nm east of Andersen Air Force Base, Guam, and is tracking north-northeastward at 13 knots.

Tropical cyclone Kofi is located approximately 1034 nm south-southeast of Pago Pago, and has accelerated to track east-southeastward at 28 knots over the past six hours. The final warning on this system has been issued.

A tropical low located 1,350 km north east of Cairns, Australia is expected to form into a tropical cyclone tomorrow. It is expected to move towards the Queensland coast.

NewsBytes:

Indonesia – Around 18 thousand houses were inundated in Bojongsoang, Baleendah and Dayeuhkolot sub-districts, Bandung District, West Java, on Monday, following the overflow of the Citarum River after heavy rains on Sunday.

USA – Rain in Western Washington brings warning of floods, landslides and avalanches. Several landslides in the North Bend area helped prompt the issuing of a special weather statement warning about unstable hillsides. Rangers at Mount Rainier reported 18 inches of powder from Sunday to Monday.

Wildlife

Sea Otters Rebound from Exxon Valdez Disaster

Nearly a quarter of a century after the Exxon Valdez disaster dumped 11 million gallons (40 million litres) of oil into Alaska’s Prince William Sound, sea otter numbers have rebounded to levels seen before the spill, the U.S. Geological Survey announced Friday (Feb. 28) with a new study.

Sea otters (Enhydra lutris), found along the Pacific coasts of North America and Northeast Asia, are one of more than 20 types of animals that make their home near the shore affected by the March 1989 oil spill. The disaster occurred in prime sea otter habitat, according to the USGS study. The oil “drastically reduces” the ability of the otters’ fur to provide insulation, the report said.

It is estimated that several thousand sea otters perished because of the spill, the USGS said in a statement, and subsequent monitoring showed that the animals were slow to recover, likely because oil lingering in their environment continued to affect them.

“Although recovery timelines varied widely among species, our work shows that recovery of species vulnerable to long-term effects of oil spills can take decades,” said lead author of the study, Brenda Ballachey, a USGS research biologist.

Researchers used a variety of methods to gauge how sea otters are fairing today. The scientists conducted aerial surveys that counted the animals’ numbers, examined causes of sea otter deaths and looked at gene expression in sea otters to check for influence from oil exposure. All of these measures pointed to shifts back to pre-spill levels.

The aerial surveys found numbers of sea otters comparable to those seen before the tanker Exxon Valdez ran aground on Bligh Reef, and the gene expression data suggested a reduction in oil exposure since 2008. However, another recent study involving USGS scientists found protected pockets of oil that had been virtually unchanged since the spill.

Examinations of sea otter carcasses showed that most deaths now occur in very old and very young sea otters, as was the pattern before the spill. By contrast, most deaths occurred among middle-aged sea otters in the spill’s aftermath.

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Global Warming

Global Warming Slows Down Antarctica’s Coldest Currents

A shift from briny to fresh in Antarctica’s ocean waters in recent decades could explain the shutdown of the Southern Ocean’s coldest, deepest currents, a new study finds.

The cold currents, called the Antarctic Bottom Water, are chilly, salty rivers that flow from the underwater edge of the Antarctic continent north toward the equator, keeping to the bottom of the seafloor. The currents carry oxygen, carbon and nutrients down to the deepest parts of the ocean. Previous studies have found this deep, dense water is disappearing, though researchers aren’t sure if the shrinkage is part of a long-term trend linked to global warming, or a natural cycle.

The new study suggests that Antarctica’s changing climate is to blame for the shrinking Antarctica Bottom Water. In the past 60 years, the ocean surface offshore Antarctica became less salty as a result of melting glaciers and more precipitation (both rain and snow), researchers reported Sunday (March 2) in the journal Nature Climate Change. This growing freshwater layer is the key link in a chain that prevents the cold-water currents from forming, the study finds.

“Deep ocean waters only mix directly to the surface in a few small regions of the global ocean, so this has effectively shut one of the main conduits for deep-ocean heat to escape,” said Casimir de Lavergne, an oceanographer at McGill University in Montreal.

Holey ice

The linchpins linking freshwater and cold currents are polynyas, or natural holes within sea ice. These persistent regions of open water form when upwellings of warm ocean water keep water temperatures above freezing, or when winds drive sea ice away from the coast.

Polynyas are one of the main sources of Antarctica Bottom Water. Polynyas act like natural refrigerators, letting frigid temperatures and cold winds chill seawater and send it sinking down to the ocean bottom. As the cold water sinks, warmer ocean water comes up to take its place, maintaining the polynya’s open water.

But as Antarctica’s ocean surface water has freshened, fewer polynyas have appeared, the researchers found. That’s because the fresher water is less dense. Even if the water is very cold, it doesn’t sink as readily as saltier water, de Lavergne explained. The freshwater acts like a lid, shutting down the ocean circulation that sends cold water to the seafloor, and brings up warm water into the polynyas.

“What we suggest is, the change in salinity of the surface water makes them so light that even very strong cooling is not sufficient to make them dense enough to sink,” de Lavergne told Live Science. “Mixing them gets harder and harder.”

Trapped heat

In addition to warming and shrinking the Antarctic Bottom Water currents, the reduction in polynyas could be trapping extra heat in the Southern Ocean, de Lavergne said.

“If the warm waters aren’t able to release their heat to the atmosphere, then the heat is waiting in the deep ocean instead,” he said. “This could have slowed the rate of warming in the Southern Hemisphere.”

De Lavergne cautioned that the heat-storage effect is localized and not related to the so-called global warming “hiatus” — the recent slowdown in the rise of global surface temperatures.

Antarctic iceberg 01 02

Disease

Human infection with avian influenza A(H7N9) virus – update

On 27 February, 28 February and 1 March 2014, the National Health and Family Planning Commission (NHFPC) of China notified WHO of eight additional laboratory-confirmed case of human infection with avian influenza A(H7N9) virus.

WHO advises that travellers to countries with known outbreaks of avian influenza should avoid poultry farms, or contact with animals in live bird markets, or entering areas where poultry may be slaughtered, or contact with any surfaces that appear to be contaminated with faeces from poultry or other animals. Travellers should also wash their hands often with soap and water. Travellers should follow good food safety and good food hygiene practices.

Volcanos

Roundup of Global Volcanic Activity:

Nishino-shima (Volcano Islands): The island continues to grow as lava flows slowly spread into several directions. This is shown nicely by the latest aerial survey pictures the Japanese Coast guard took on 28 Feb. The most active flow fronts are currently at the southern shore while advance on the northern and eastern margins of the flow field has slowed down. Two prominent cones have formed around the main vents, the smaller and younger of which still has strombolian activity as well. One can note the closure of a small bay that had been formed in early Feb by lava flow tongues; eventually, the two flows touched and separated the bay from open water, turning it into a small lake. Several other small bays present now (or, on 28 Feb, at least) are in the process of forming and probably become lakes as well in the future. The discoloration of the enclosed water comes from dissolved gasses and fine material in suspension. The fate of these lakes will depend on the evolution of the lava flows. If new flows cover them, they might well disappear as well.

Kilauea (Hawai’i): (3 Mar) Summit tiltmeters record weak inflationary tilt, the lava-lake level dropped slightly to around 39m (128ft) below the floor of Halema`uma`u

Pacaya (Guatemala): (3 Mar) The latest eruptive phase of the volcano continues at decreased strength. The second paroxysm of Pacaya this year, only about 6 weeks after the previous one in January, started yesterday morning with lava fountains, associated ash emissions, as well as a new lava flow that quickly reached about 2 km length. The current seismic signal suggests that activity continues at a decreasing trend. Images from later during yesterday showed that lava fountaining and lava effusion had already decreased significantly after the first hours. A new phase of increased activity at the volcano began today. Strombolian explosions became more intense, ejecting incandescent bombs to approx. 200 m above the crater, and since this morning, a new lava flow started to descend from the summit on the western flank. The activity surge is reflected by a strong, gradual increase of tremor. Eruptive activity continues at reduced intensity as the seismic signal indicates. As of yesterday, INSIVUMEH reported still active flows from the vent at the western base of the Mackenney cone. Their length was between 1300-1600 m and they reached the southern base of the cone. Weak explosions were observed at the summit vent.

Ubinas (Peru): According to the Geophysical Institute of Peru (IGP), magma has arrived near or at the crater of the volcano. This is indicated by a recent swarm of hybrid earthquakes and a weak thermal anomaly that has been detected at the summit during the past 3 weeks. In a press article, the head of IGP, Orlando Macedo, said that that based on the low energy of the seismic signals recorded, the quantity of new magma that has risen is estimated to be small and that the most likely scenario for the near to medium future are smaller (explosive) eruptions from the volcano.