Wednesday, October 12, 2016

Glacial Wisdom

Before we launch into continuing discussion of the startling sudden shift of society toward agriculture about 10,000 BC, accelerating human society toward what is termed the rise of civilization, I digress with a few personal observations of the remnants of glaciation in the area where I grew up and later lived and worked. These memories not only demonstrate the reality of past Pleistocene glaciation but also provide awareness of past glacial events as they clarify geologic phenomena still evident today. Past and present observations are tantamount to an educational “field trip.” Nothing reinforces book learning and class discussion better than in-person visits to sites where historic events occurred.

My childhood in central New York State provided many remnants of earth’s last continental glaciation. At the time I was unaware of glacial history in my home town region. In nearby Syracuse, there was a ski area and country club called Drumlins. As a child I did not understand its geological significance, or any details of my home town area’s glacial heritage even though the last continental glacier had retreated from the region only yesterday in geological terms. Years later I discovered how the country club acquired its name.

My brother became interested in model airplane building in his teen years. Some of his large glider models were capable of moderately long flight. As a young observer three years his junior, I “helped out” several times as he launched his gliders from the highest hills in our neighborhood. What were these glider-launching venues? Later I discovered the launch hills were drumlins, deposits of sediment formed in elongated north to south teardrop shapes under the slowly south-flowing ice sheet perhaps 15,000 years ago. The ice sheet flowed over glacial till, unsorted deposits of sediment, molding them into long, tapered hills blunt on their northern end and tapered at their southern terminus. These childhood glider launching venues seldom exceeded 50m in elevation.

The Seneca River flowing through our village was the main drainage of the famous Finger Lakes of New York State and became my personal favorite site for carp fishing. These elongated lakes were also generally north/south oriented, formed by the glacial ice sheet slowly following and deepening previously existing stream valleys. The largest finger lake is Seneca Lake, 618 feet deep. At 427 feet elevation, the bottom of Seneca Lake is actually below sea level. Giant lake trout and brown trout inhabit the deep lake. My parents knew personal friends with a home on Seneca Lake during my childhood. Watkins Glen State Park was the nearby site of a beautiful hanging valley waterfall, the stream bed having been “left hanging” by the passage of forceful glacial ice. When we visited our family friends I was unaware we were treading on ancient glacial topography.

Some of our family’s favorite summer visits were stops at Fair Haven Beach State Park on the shores of Lake Ontario, less than an hour away from our home. Lake Ontario is one of five Great Lakes. These are the largest glacial lakes in the world. The Great Lakes did not exist when the Rise of Civilization commenced in Mesopotamia and other places in the Old World. In 12,000 BC most of the drainage and meltwater from the continental ice sheet in northern North America flowed south and west toward the Mississippi River. But by 4,000 BC the present Great Lakes drainage patterns became established as the ice sheet melted. The water then began to flow northeast following the present St. Lawrence River. This exceedingly brief narrative does not begin to relate the complexity of events in North America after the Wisconsin glacier began its demise.

Since I moved away from Central New York state in the early 1950s, I have become aware of additional phenomena in the US Northeast and Midwest as a result of the former presence of the Wisconsin ice sheet. Not ten miles from the school district where I formerly taught, I recently visited a surreal glacial “leftover” in a place called Pyramid Mountain County Park in Morris County NJ. Tripod rock has a mass of 160 tons. It rests on three much smaller rocks as though suspended several feet above ground. It is a glacial erratic carried and dropped by the mighty ice sheet perhaps 18,000 BC, transported from an unknown location farther north. I enjoyed telling my former students that our school building rested on land almost exactly at the Wisconsin glacier’s southern-most edge. We wondered whether the ice began at one definite spot, or if a few snowbanks began to appear here and there as one hiked from south to north.

What was life on Earth like during the Wisconsin ice age? The Genesis account of man’s experience details mainly events of the past several thousand years. But prior to the few thousand years recorded primarily from around time of Abraham, we have a sparse record of human life. We count many contemporary benefits of the Wisconsin glacier event, including (1) melting ice bringing nutrient-rich alluvial soil to the plains (2) melting glaciers, especially in the Himalayas, bringing water to the Earth (3) human migration, facilitated with the creation of land bridges during long periods of low sea level (4) melting glaciers forming an abundance of fresh water lakes (5) glacial retreat forming deep, safe harbors (6) retreating ice sheets leaving behind spectacular scenery.

We close with one more personal memory of the lingering benefit of the last Ice Age. Northern New Jersey is the home of The Great Swamp National Wildlife Refuge in southern Morris County. The melting ice sheet left a moraine (sediment deposited at the edge of a glacier) to plug normal drainage from the watershed. Glacial Lake Passaic formed. The remaining swamp is now but a 12 square mile remnant of the Wisconsin glacier which covered the area with a thick ice sheet only 15,000 years ago. It now functions as a habitat for 244 species of birds and other diverse wildlife. The swamp acts as a natural water filter and provides a hiking site. I organized several after-school bus trips to the swamp for our hiking club.

God exclaimed in the first chapter of the Bible that each event of creation “was good.” On the sixth day he created man in his own image and instructed him to rule “over every living creature.” He “saw all that he had made, and it was very good.” Our Creator is also aware of glaciation events which come, go, advance, and recede. He is aware of all natural cycles. God creates and sustains hundreds of beneficial cycles for the benefit of his children. As we examine these events we discover they are all “very good.”