Earthquakes

Magnitude 5+ Earthquakes – Global

6.5 Earthquake hits the Pacific-Antarctic ridge.

6.0 Earthquake hits Tonga.

5.8 Earthquake hits Vanuatu.

5.5 Earthquake hits Tajikistan.

5.0 Earthquake hits the Bougainville region, Papua New Guinea.

Global Warming

Antarctic Ice Shelf in Last Throes of Collapse

A vast Antarctica ice shelf that partly collapsed in 2002 has only a few years left before it fully disappears, according to a new study.

Radar data reveals that the Larsen B ice shelf could shatter into hundreds of icebergs by 2020, researchers reported Thursday (March 14) in the journal Earth and Planetary Science Letters.

“It’s really startling to see how something that existed on our planet for so long has disappeared so quickly,” lead study author Ala Khazendar, a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, told Live Science.

An ice shelf is like a floating ice plateau, fed by land-based glaciers. The Larsen B ice shelf existed for 12,000 years before it fell apart in 2002, separate studies showed. The ice shelf is on the Antarctica Peninsula, the strip of land that juts northward toward South America. Larsen B is about half the size of Rhode Island, some 625 square miles (1,600 square kilometres).

Because the ice shelf is already in the ocean, its breakup won’t further boost sea level rise. But Khazendar and his co-authors also discovered that the glaciers feeding into Larsen B’s remaining ice shelf have dramatically thinned since 2002.

“What matters is how much more ice the glaciers will dump into the ocean once this ice shelf is removed,” Khazendar said. “Some of these glaciers are most likely already contributing to sea level rise because they are in the process of accelerating and thinning.”

The Leppard and Flask glaciers thinned by 65 to 72 feet (20 to 22 meters) between 2002 and 2011, the new study reported. The fastest-moving part of Flask Glacier sped up by 36 percent, to a speed of 2,300 feet (700 m) a year.

The glaciers that were behind the vanished section of the Larsen B ice shelf sped up by as much as 8 times their former rate after the ice crumbled over a six-week period in 2002, earlier studies showed.

The northwestern part of the Larsen B ice shelf is also becoming more fragmented, the researchers said. But the southeastern part is cracking up. A huge rift has appeared just 7.5 miles (12 km) from the grounding line, where the ice loses contact with the ground and starts floating on the ocean, the study reported. This crack marks where the ice shelf may start to break apart, the researchers said.

The Antarctica Peninsula is one of the world’s fastest-warming places, with an average rise in air temperature of 5 degrees Fahrenheit (2.8 degrees Celsius) in the past 50 years, according to the British Antarctic Survey. This March, the northern tip of the peninsula set an unofficial heat record of slightly above 63 F (17 C).

Researchers think the surface warming is melting the ice shelves, triggering a cascade of events that eventually leads them to catastrophically collapse. But recent research also points to melting from below, from warmer ocean water.

Disease

Warning of Hepatitis in Mexico

The Centers for Disease Control and Prevention is cautioning travellers visiting Mexico in the wake of a recent hepatitis A outbreak.

According to the CDC, as of May 1, more than two dozen cases of hepatitis A have been reported by U.S. travelers who visited Tulum, Mexico, a popular tourist destination, between Feb. 15 and March 20 of this year. As a result, the CDC is recommending that travelers headed south of the border get vaccinated for hepatitis A.

The organization also advises travelers to eat and drink safe foods and beverages as well as to practice good hygiene and cleanliness.

Health Warning in Hong Kong

The Hong Kong Centre for Health Protection (CHP) of the Department of Health today (May 14) called on the public to maintain vigilance against hand, foot and mouth disease (HFMD) and enterovirus 71 (EV71) infection, as the latest surveillance data shows that Hong Kong is entering the peak season for both.

“The CHP recorded an increasing number of institutional outbreaks of HFMD in the recent two weeks. There were nine and 10 institutional HFMD outbreaks in the week ending May 9 and the first four days (May 10-13) of this week respectively as compared with between zero and four outbreaks per week in previous months.”

As for EV71 infection in 2015, the CHP recorded 18 cases as of May 15, among which one patient developed a severe complication. Fifteen of the cases were recorded in recent four weeks.

“The summer peak season for HFMD and EV71 is usually from May to July. The local activity is expected to increase in the next few weeks.

Wildfires

Wildfires – British Columbia, Canada – Update

The Little Bobtail Lake fire has now destroyed about 24,000 hectares of forest near Prince George is believed to have been started by people.

The blaze had been 20-per-cent under control Saturday, but winds that gusted from 35 to 50 km/h resulted in the fire expanding, so that it was just 15-per-cent under control as of Monday.

On May 10, 65 homes in Bulkley-Nechako were ordered evacuated, although only two people are receiving support because many of the homes are recreational cabins. Another 774 homes are under alert, which means their occupants must be ready to leave on short notice.

In Fraser-Fort George, 130 homes were evacuated May 10 and of the 13 people that left those homes, 11 are still receiving help. A further 122 homes are under alert.

Volcanos

Roundup of Global Volcanic Activity

Sakurajima (Kyushu, Japan): After a very busy 17 May, with several strong explosions sending ash plumes to up to 16,000 ft (4.5 km) altitude, the volcano has been relatively calm during 18 and most of 19 May. A filming team of VolcanoDiscovery being on location, we could observe hour-long phases of near-continuous mild to moderate ash venting. After approx. 10 hours of almost no visible activity, a probably strong explosion occurred yesterday night at around 11 pm, lasting several minutes, producing numerous lightning and heavy ash fall on the eastern sector. Cloud cover prevented detailed observations.

Dukono (Halmahera): Activity seems to be on the rise – the volcano continues to produce near-continuous ash-rich explosions. Ash plumes to approx. 10,000 ft (3 km) altitude have been reported almost daily over the past days by Darwin VAAC.

Turrialba (Costa Rica): Several new mild to moderately strong ash eruptions have occurred at the volcano during the past days. In particular, on 16 May, one of the most intense phases of ash emissions so far took place from the volcano’s western summit crater between midnight and 15:40 local time. Ash plumes extended up to 50 km to the west and caused mild ash fall in places as Heredia and Alajuela towns. A 5 km exclusion zone around the crater is in place.

Reventador (Ecuador): The volcano’s activity remains elevated. Mild to moderate explosions occur frequently from the summit vent, where viscous lava is being extruded and also produces an active lava flow, approx. 300 m long on the southwestern flank. IGPEN reported dozens of explosions on most days, and up to more than 60 on a peak of activity on 8 May.

Piton de la Fournaise (La Réunion): The eruption continues with strong lava effusion. As of 19 May evening, the lava flow had been at 3 km from the coastal road, having advanced 750 m during the past 24 hours. Its advance is likely to be slower from now on, as the front is now in the flatter area of the “Grandes Brulés”. Nevertheless, hopes are rising that the flow might reach the sea.