USGS Documents Glaciers are Melting

Wiki tells that South Cascade Glacier is a large alpine glacier in the North Cascades of Washington state.  An alpine glacier forms on a mountain slope in contrast to the relatively flat ice sheets of Antarctica and Greenland.  Glaciers react to both snowfall amounts and temperature, providing a a portrait of climate trends.  The South Cascade Glacier is the head of the Cascade River which flows into the Skagit River and eventually into Pugent Sound.

Fifty-Year record of glacier change shows photographs of the South Cascade Glacier in 1928, 1959, 1979, and 2003.  As you might expect, the photographs illustrate a vivid retreat of the glacier, especially during the last interval.  You can see even further retreat on Google Earth at  48°22'19.15"N, 121° 4'9.26"W (pretty cool scenery), or Bing.  The glacier is unique because it melts into a single tributary.

The U.S. Geological Service measures the health of glaciers using photographs and with network of stakes distributed over the glacier.  As you would imagine, snowfall at the head (top) of the glacier compacts and slides downhill.  Over a year's time, the lower portion of the glacier experiences ablation, which is the loss of mass due to melting or calving.

South Cascade Glacier lost mass at an almost constant rate during the late 1950s to the late 1960s, then gained mass until 1976, and has been losing mass at a fairly constant and rapid rate since 1977.  Just as hurricane activity is affected by El Nino, the glacier is also affected by the Pacific Decadal Oscillation (PDO) which is and ocean-climate oscillation similar to El Nino.  This periodically brings additional moisture to the glacier, but recently the increasing climate temperatures have negated the historical affect of PDO.

Since 1958, South Cascade Glacier has lost almost half of its mass.  We have unmistakable climate trends.

Comments

[TheSmileyOne]

Do you believe these obvious climate changes to be anthropomorphic, or do you attribute it to solar cycles?

[Zark]

I will be posting tomorrow about the Milankovitch Theory. I believe either could be responsible, if not both for the climate changes being experienced. I am concerned about the huge amounts of carbon dioxide that 7 billion people are placing into the atmosphere. Although there is not a smoking gun, it does not seem healthy.