INCREASED THINNING OF WEST ANTARCTIC GLACIERS

Glaciers in West Antarctica are shrinking at a rate substantially higher than observed in the 1990s. They are losing 60 percent more ice into the Amundsen Sea than they accumulate from inland snowfall.

The study was conducted by a science team from NASA, U.S. universities and from the Centro de Estudios Científicos in Chile. It is based on satellite data and comprehensive measurements made in 2002 by a science team aboard a Chilean P-3 aircraft equipped with NASA sensors. Science Express published the findings today.

The ice loss from the measured glaciers corresponds to an annual sea-level rise of .008 inches (.2 millimeters) or more than 10 percent of the total global increase of about .07 inches (1.8 millimeters) per year.

For a balanced glacial system, the amount of glacier ice melting or flowing into the sea roughly equals the ice formed from snow accumulations further inland. The scientists report the Amundsen Sea glaciers are not in balance.

Bob Thomas, a science team member with EG&G Services at the NASA Goddard Space Flight Center's Wallops Flight Facility, Wallops Island, Va., commented that as the glaciers flow to the ocean, they become afloat to form ice shelves. "The ice shelves act like a cork and slow down the flow of the glacier," Thomas said.

The scientists noted the earth underneath the ice is further below sea level than had been assumed, so the ice is thicker than once thought. This increases the amount of ice each glacier can discharge into the ocean as its speed increases. It makes it easier for the thinning glacier to float free from its bed, and thus further 'loosen the cork'," Thomas said.

Thomas said in the last 10 years the ability to accurately measure glaciers worldwide has greatly improved. Measurements from aircraft and satellites like NASA's Ice, Cloud and Land Elevation Satellite (ICESat), launched in 2003, have greatly improved accuracy.

Source-NASA
http://www.nasa.gov/centers/goddard/news/topstory/2004/0923westglaciers_prt.htm

Evolution of the computer keyboard

The creation of the present computer keyboard began with the invention of the typewriter. A few important technological developments created the change of the typewriter into the computer keyboard. The teletype machine was introduced in the 1930s; this technology combined the technology of the typewriter (used as an input and a printing device) with the telegraph. Elsewhere, punched card systems were combined with typewriters to create keypunches. Keypunches were the basis of early adding machines and IBM was selling over one million dollars worth of adding machines in 1931.

Early computer keyboards were first equipped from the punch card and teletype technologies. In 1946, the Eniac computer used a punched card reader as its input and output device. In 1948, the Binac computer used an electromechanically controlled typewriter to in cooperation input data directly onto magnetic tape and to print results. The emerging electric typewriter additional improved the technological tie-up between the typewriter and the computer. There were many electromechanical steps in transmitting data between the keyboard and the computer that slowed things down. With electric keyboards, the keyboard's keys might now send electronic impulses straight to the computer and save time. By the late ‘70s and early on ‘80s, the entire computers used electronic keyboards and VDTs