Earth Changes
QUITO - Lava was rising anew in the crater of Ecuador's Reventador volcano on Monday, a day after bursts of ash forced temporary closure of the capital's airport.
The sun is nearly 150 million kilometres away, but it seems to have Earth's rivers on a leash. The flow of a huge South American river - and thus the rainfall that feeds it - appears to rise and fall with the number of sunspots.
Though scientists reject the climate sceptics' assertion that the sun's activity can explain global warming, many have wondered whether it can affect rainfall. No one has been able to test this, though, as it has proved difficult to collate rainfall measurements over long timescales and areas large enough to rule out local variations.
Though scientists reject the climate sceptics' assertion that the sun's activity can explain global warming, many have wondered whether it can affect rainfall. No one has been able to test this, though, as it has proved difficult to collate rainfall measurements over long timescales and areas large enough to rule out local variations.
Throughout history, the changing fortunes of human societies in Asia have been linked to variations in the precipitation resulting from seasonal monsoons. A new paper published in the British journal Nature Geoscience suggests that variations in monsoon climate over longer time scales also influenced the evolution of the world's highest mountain chain, the Himalaya.
The climate over much of Asia is dominated by seasonal winds that carry moist air over the Pacific Ocean into East Asia and over the Indian Ocean into South Asia. The East and South Asian monsoons are responsible for most of the rainfall in these regions. Although the time when these monsoon patterns were first established is unknown, many lines of evidence suggest that they first came about at least 24 million years ago.
© iStockphoto/Andrzej Stajer
Himalayas (view on Ama Dablam in Khumbu Valley). Variations in monsoon climate over longer time scales have influenced the evolution of the world's highest mountain chain, the Himalaya.
Himalayas (view on Ama Dablam in Khumbu Valley). Variations in monsoon climate over longer time scales have influenced the evolution of the world's highest mountain chain, the Himalaya.
The climate over much of Asia is dominated by seasonal winds that carry moist air over the Pacific Ocean into East Asia and over the Indian Ocean into South Asia. The East and South Asian monsoons are responsible for most of the rainfall in these regions. Although the time when these monsoon patterns were first established is unknown, many lines of evidence suggest that they first came about at least 24 million years ago.
A NASA-led research team has used satellite data to make the most precise measurements to date of changes in the mass of mountain glaciers in the Gulf of Alaska, a region expected to be a significant contributor to global sea level rise over the next 50-100 years.
Geophysicist Scott Luthcke of NASA's Goddard Space Flight Center, Greenbelt, Md., and colleagues knew from well-documented research that changes in the cryosphere - glaciers, ice caps, and other parts of the globe covered year-round by ice -- are a key source of most global sea level rise. Melting ice will also bring changes to freshwater resources and wildlife habitat. Knowing that such ice-covered areas are difficult to observe consistently, the team worked to develop a satellite-based method that could accurately quantify glacial mass changes across seasons and years, and even discern whether individual glacier regions are growing or shrinking.
© NASA
The mass changes of the Gulf of Alaska glaciers are computed from the Gravity Recovery and Climate Experiment (GRACE) inter-satellite rate data from April 2003 through September 2007. Using space-borne gravity measurements to assess glacier mass balance NASA scientists determine mass variations along the Gulf of Alaska. Areas of deep blue like the areas around Glacier Bay and the Yakutat Icefield represent significant mass loss where inland areas of dark gray represent slight mass gains.
The mass changes of the Gulf of Alaska glaciers are computed from the Gravity Recovery and Climate Experiment (GRACE) inter-satellite rate data from April 2003 through September 2007. Using space-borne gravity measurements to assess glacier mass balance NASA scientists determine mass variations along the Gulf of Alaska. Areas of deep blue like the areas around Glacier Bay and the Yakutat Icefield represent significant mass loss where inland areas of dark gray represent slight mass gains.
Geophysicist Scott Luthcke of NASA's Goddard Space Flight Center, Greenbelt, Md., and colleagues knew from well-documented research that changes in the cryosphere - glaciers, ice caps, and other parts of the globe covered year-round by ice -- are a key source of most global sea level rise. Melting ice will also bring changes to freshwater resources and wildlife habitat. Knowing that such ice-covered areas are difficult to observe consistently, the team worked to develop a satellite-based method that could accurately quantify glacial mass changes across seasons and years, and even discern whether individual glacier regions are growing or shrinking.
Antarctica overall has cooled measurably during the last 35 years - despite a global average increase in air temperature of 0.06 degrees Celsius during the 20th century - making it unique among the Earth's continental landmasses, according to a paper published today in the online version of Nature.
Researchers with the National Science Foundation (NSF) Longterm Ecological Research (LTER) site in Antarctica's Dry Valleys - a perpetually snow-free, mountainous area adjacent to McMurdo Sound - argue in the paper that long-term data from weather stations across the continent, coupled with a separate set of measurements from the Dry Valleys, confirm each other and corroborate the continental cooling trend.
Researchers with the National Science Foundation (NSF) Longterm Ecological Research (LTER) site in Antarctica's Dry Valleys - a perpetually snow-free, mountainous area adjacent to McMurdo Sound - argue in the paper that long-term data from weather stations across the continent, coupled with a separate set of measurements from the Dry Valleys, confirm each other and corroborate the continental cooling trend.
BEIJING - A strong magnitude 6.5 earthquake struck remote northwestern China on Monday, the U.S. Geological Survey said. There were no immediate reports of casualties.
One of the coldest Octobers on record in the Interior has the Yukon River grinding to a halt and residents settling in for winter.
October 2008 went down as Fairbanks' fourth-coldest October on record since 1904, according to meteorologist Rick Thoman with the National Weather Service in Fairbanks. The average temperature of 15.1 degrees was 8.4 degrees below normal.
The coldest October on record in Fairbanks was in 1996, which had an average temperature of 13.1 degrees.
"That year we had three days in a row with lows in the mid 20s below," Thoman recalled. "We didn't have anything quite like that this year.
October 2008 went down as Fairbanks' fourth-coldest October on record since 1904, according to meteorologist Rick Thoman with the National Weather Service in Fairbanks. The average temperature of 15.1 degrees was 8.4 degrees below normal.
The coldest October on record in Fairbanks was in 1996, which had an average temperature of 13.1 degrees.
"That year we had three days in a row with lows in the mid 20s below," Thoman recalled. "We didn't have anything quite like that this year.
© REUTERS/M. Rauschert/Census of Marine Life handout
Megaleledone setebos, a shallow-water circum-Antarctic species endemic to the Southern Ocean is seen in this undated handout
Megaleledone setebos, a shallow-water circum-Antarctic species endemic to the Southern Ocean is seen in this undated handout
Researchers in 82 nations, whose 10-year study aims to help protect life in the seas, found a mysterious meeting place for white sharks in the eastern Pacific Ocean and algae thriving at -25 degrees Celsius (-13 Fahrenheit) in the Arctic.
"We are approaching a picture of the oceans ... from micrcobes to whales," said Ron O'Dor, co-senior scientist of the census of the 2007-08 findings by up to 2,000 scientists.
Howling Winds, Up To 4 Feet Of Snow Hit High Plains
As snow depth totals approached 4 feet in the higher Black Hills and winds gusting to 50-plus mph continued to howl, top-level state officials had a simple message for anyone thinking of trying to drive in western South Dakota's blizzard: Don't.
And they stressed the storm will keep causing problems as it spreads east through Friday.
"This is a dangerous storm," Gov. Mike Rounds told reporters in a telephone conference call early Thursday evening.
"Western South Dakota is basically under a no-travel advisory."
The storm already has dropped 45.7 inches of snow near Deadwood, in the northern Black Hills. Reports of 10 inches to 2 feet of snow were received from many West River counties. In some towns, residents reported drifts were blocking their doorways.
In Shannon County, in the southwestern corner of the state, 20-foot snowdrifts were reported on the Pine Ridge Indian Reservation.
As snow depth totals approached 4 feet in the higher Black Hills and winds gusting to 50-plus mph continued to howl, top-level state officials had a simple message for anyone thinking of trying to drive in western South Dakota's blizzard: Don't.
And they stressed the storm will keep causing problems as it spreads east through Friday.
"This is a dangerous storm," Gov. Mike Rounds told reporters in a telephone conference call early Thursday evening.
"Western South Dakota is basically under a no-travel advisory."
The storm already has dropped 45.7 inches of snow near Deadwood, in the northern Black Hills. Reports of 10 inches to 2 feet of snow were received from many West River counties. In some towns, residents reported drifts were blocking their doorways.
In Shannon County, in the southwestern corner of the state, 20-foot snowdrifts were reported on the Pine Ridge Indian Reservation.
© Reuters
Fulfilling forecasters' predictions for a high number of strong hurricanes, one storm after another in August and September hit the Bahamas, Cuba, Dominican Republic, Haiti, Jamaica, the British Turks and Caicos Islands, and the southeastern United States. Fay, Gustav, Hanna and Ike followed within weeks of each other.
Haiti - the poorest country in the Americas - is ill prepared to prepare for storms or cope with their consequences, and suffered the highest number of deaths when it was hit in turn by all four. It's hard to pin down an exact toll from floods and mudslides caused by a series of storms in August and September 2008 - since many corpses were washed out to sea - but police and local authorities say it was around 700.
