Basal slippage

Water flow under ice on the trail

Yesterday we walked part of the way on the trail around Sutherland Pond in the Ooms Conservation Area in Old Chatham, NY, The path was treacherous because of the melting ice, so we didn’t make it the whole way. But we were mesmerized by the patterns of water flowing under the ice,

I assume this process is similar to the basal slippage seen for glaciers in temperate zones. Because of human-caused global warming, the ice melts underneath. Then the remaining ice slides on the water layer, leading to more rapid loss of the glacier.

A world in a grain of sand

My evening flight from Kathmandu to Delhi was canceled, so I had to take one five hours earlier. Although I wasn’t happy about the resulting extra layover time, flying earlier in the day meant that I had a glorious panorama of the Himalayas most of the way. Since Delhi is directly west of Kathmandu the 500-mile flight path was as if made to order for the view.

The Himalayas are a feature of our world that call for silent awe, and need no supporting adjectives, such as “stunning” or “snow-covered.” They’re the antithesis of another, also beautiful, feature of our world, Cape Cod. Its glacial drift formations are a gentle lullaby to the Himalayan symphony.

However, as we flew along the southern edge of the grand plateau, I took my eyes, or ears, away from that symphony from time to time because I couldn’t put down the book I was reading. In The Path: A One-Mile Walk through the Universe. In the book, Chet Raymo describes the path he took for 37 years from his house in North Easton, Massachusetts to the Stonehill College campus where he taught physics and astronomy.

Just as we were passing from Nepal into India, I read this:

Millions of years ago India, drifting northward on the mobile surface of the earth, nudged into Asia and began pushing upward a double-thickness slab of the Earth’s crust known as the Tibetan plateau, the front range of which are the towering Himalayas.

Raymo goes on to explain how sunlight beating down on the plateau produces warm air. As it rises, moist air from the Indian Ocean takes its place. This creates the Indian monsoon cycle. Heavy rainwater combines chemically with the Himalayan rock. The weathering takes carbon dioxide out of the air.

As the mountains rose and eroded, the amount of carbon dioxide in the atmosphere decreased and Earth began to cool. On Northern continents ice sheets formed and moved across the land, grinding, abrading.

Thus, mountains in Asia caused glaciers in New England and those in turn built the Cape Cod beaches where we swim every summer. The symphony is magnificent, but it needs the lullaby to follow.

India continues its journey northward; the Himalayas continue to rise; the sun still beats down; the monsoons cycle onward, and the rains take carbon dioxide out of the air.

But don’t look for the glaciers to return anytime soon to build up more places to plant your beach umbrella. Our technologies are now overwhelming these natural processes. Combustion of fossil fuels is adding far more greenhouse gases to the air, warming the world and covering up those glacial sands with rising sea water.

Bring on the flood

Imja Tsho

Imja Tsho

Today’s BBC News reports on an important development in Nepal, one which should be a warning to us all (Nepal drains dangerous Everest lake).

Nepal’s army has just completed lowering Lake Imja by 10 ft. This is because it was in danger of flooding downstream settlements with over 50,000 people.

Lake Imja, near Mount Everest (Sagarmatha) at 16,400 ft altitude, is one of thousands of such glacial lakes in the Himalayas. Many of the lakes are filling fast because of accelerated melting of glaciers due to rising temperatures.

The Himalaya region has been described as the third pole of the earth. It is melting, just as the Arctic and Antarctic are.

Lake Imja is a good example of that melting. It is a new lake, composed of glacial meltwater blocked by a terminal moraine. In 1962, it was 7.5 acres, and is now over 260.

I can only guess at the enormous cost of the six-month project, not just in dollars, but in terms of using up limited Nepali resources. It has been necessary to save lives, but sherpas in the region say there are many more lakes that endanger communities.