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3 February, 1999Good morning from Christchurch!! Today I am going to the Westland region of New Zealand to join Dr. Denton as he and some colleagues study the Franz Joseph Glacier. Glaciers always advance, they never really retreat. Sometimes, however, the ice melts even faster than it advances, and in that case the terminal, or end, face of the glacier moves back up the mountain and appears to be retreating. The great mass of ice higher up the mountain pushes the ice down the Franz Joseph Valley at great speeds, but- like most glaciers in the worls - this past century has beeen a story of steady retreat and only the odd advance. The last great ice age of 15,000 to 20,000 years ago saw the glaciers reach right down to the sea. then warmer weather came and they may have retreated even further than their current position. In the 14th century, the "Little Ice Age" began and for centuries the glaciers advanced, reaching their greatest extent around 1750. At the Franz Joseph Glacier, the terminal moraines from that last major advance cam be clearly seen. In the nearly 250 years since then, the glaciers have steadily retreated and the terminal face is now several kilometers back from its first recorded position in the late 19th century and even from the recorded position of the 1930's. From 1965 tp 1968 the Franz Joseph Glacier made brief advance of about 180m and in 1985 they started to advance and have moving forward steadily and dramatically ever since. By dramatic I mean about 70cm a day! No one is quite sure why this is happening. It could be cooler or more overcast, or the result of heavy snowfalls ten or 15 years ago. I will spend several days with Dr. Denton and will let you know what I find out there. Back to more ice!! Hillary ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com
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