NASA Image Shows La Nina-Caused Woes Down Under

The current La Nina in the Pacific Ocean, one of the strongest in the past 50 years, continues to exert a powerful influence on weather around the world, affecting rainfall and temperatures in varying ways in different locations. For Australia, La Nina typically means above-average rains, and the current La Nina is no exception. Heavy rains that began in late December led to the continent's worst flooding in nearly a half century, at its peak inundating an area the size of Germany and France combined. The Associated Press reports about 1,200 homes in 40 communities are underwater and about 11,000 others are damaged, resulting in thousands of evacuations and 10 deaths to date.

On Jan. 7, 2010, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft captured this image of the inundated city of Rockhampton, Queensland, Australia. With a population of 75,000, Rockhampton is the largest city affected by the current flooding. Torrential rains in northeastern Australia caused the Fitzroy River to overflow its banks and flood much of the city and surrounding agricultural lands. Both the airport and major highways are underwater, isolating the city. In this natural color rendition, muddy water is brown, and shallow, clearer water is gray. Vegetation is depicted in various shades of green, and buildings and streets are white. The image is located at 23.3 degrees south latitude, 150.5 degrees east longitude, and covers an area of 22 by 28.1 kilometers (13.6 by 17.4 miles). 

NASA Releases New Image of Massive Greenland Iceberg

On Aug. 5, 2010, an enormous chunk of ice, about 251 square kilometers (97 square miles) in size, or roughly four times the size of Manhattan, broke off the Petermann Glacier along the northwestern coast of Greenland. The Petermann Glacier lost about one-quarter of its 70-kilometer-long (40-miles) floating ice shelf, according to researchers at the University of Delaware, Newark, Dela. The recently calved iceberg is the largest to form in the Arctic in 50 years. Icebergs calving off the Petermann Glacier are not unusual. Petermann Glacier's floating ice tongue is the Northern Hemisphere's largest, and it has occasionally calved large icebergs.

Scientists are monitoring the movement of the iceberg closely. If it moves out into the narrow Nares Strait, there is the potential it could interfere with or block the loss of Arctic sea ice out of the Arctic Ocean into Baffin Bay, a sea that connects the Arctic and Atlantic Oceans. The ice could also eventually pose a hazard to shipping. This image of Petermann Glacier and the new iceberg was acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft on Aug. 12, 2010. It covers an area of 49.5 by 31.5 kilometers (30.7 by 19.5 miles) and is located at 81.1 degrees north latitude, 61.7 degrees west longitude.

ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is an imaging instrument flying on Terra, a satellite launched in December 1999 as part of NASA's Earth Observing System (EOS). ASTER is a cooperative effort between NASA, Japan's Ministry of Economy, Trade and Industry (METI) and Japan's Earth Remote Sensing Data Analysis Center (ERSDAC). ASTER is being used to obtain detailed maps of land surface temperature, reflectance and elevation. The three EOS platforms are part of NASA's Science Mission Directorate and the Earth-Sun System, whose goal is to observe, understand, and model the Earth system to discover how it is changing, to better predict change, and to understand the consequences for life on Earth.