What caused this freak climatic devia tion? Scientists interviewed by the National Geographic (Vol. LXXXIV, No. 6, December, 1943) attributed it to the accumulation of volcanic dust in the earth's atmosphere following large vol canic explosions in 1812, 1814, and 1815. Volcanic ash ejected in enormous quan tities into the atmosphere may absorb, reflect, and block up to 20 percent of the warmth-producing rays of the sun. One scientist has estimated that "three or four times the number of currently erupting volcanoes would depress the temperature [of the earth] from one to two degrees Centigrade, enough—given adequate precipitation—to initiate an ice age." Harold G. Coffin, Creation: Accident or Design? (Washington, D.C.: Review and Herald Publishing Assn., 1969), p. 238.
Abundant evidences of volcanic ac tion from the past can be seen in the western United States. Crater Lake in southern Oregon is a prime example. This peaceful lake lies in a cone-shaped depression that has replaced the top of an ancient mountain called, by modern geologists, Mount Mazama. Towering nearly as high as Mount Rainier or Mount Shasta, Mount Mazama once reigned as a Cascade monarch. Then sometime following the Flood, according to Creationist scientists, it blew off its top in a wild display of fire, smoke, and ash. The once dignified peak was trans formed into a belching smokestack, contributing a man-sized helping of ash to an already overpolluted atmosphere. Mount Mazama, though, wasn't alone in this volcanic heyday. The geological record indicates widespread volcanic eruption in the post-Flood era.
Did these eruptions precipitate an ice age? Are there evidences of massive glacial action in the United States?
The Mount Rainier area of the Pacific Northwest serves as an example of terrain showing extensive glacial activity. Emmons Glacier, on the northeast, has transformed a massive mountainside into a wide U-shaped valley—a valley totally different from the V-shaped valleys carved by rivers and streams. Below Paradise Glacier on the south side of the mountain, large areas of bedrock have been scraped smooth, leaving a shining surface with minute scratches running parallel to one another, indicating the glacier's direction of travel.
On the north side of the mountain, Carbon Glacier, a skinny river of ice, descends to an amazingly low elevation of under 4,000 feet. At the toe or terminus of the glacier a ridge of rock and sand debris stands where it has fallen off the glacier as it melts in summer. Farther down the valley other ridges of debris, called moraines, signify that the glacier has advanced to even lower elevations in past years.
Geologists studying the landforms of North America have discovered evidences of extensive glaciation in twenty-one of the States of the United States and all of Canada. Glacial phenomena that may be observed and studied in the high mountains where glaciers usually exist today are also found in the lowlands of northeastern North America. The evidence indicates these glaciers covered what is today New York City, Detroit, Chicago, and Minneapolis!
What effect did this ice sheet have on our present landscape? One interesting result was the formation of the largest inland waterway in the world—the Great Lakes. Other carving feats include Puget Sound of the Northwest and the spectacular Canadian Rockies. In addition to shaping the land, the ice sheet acted as a large dump truck, depositing billions of tons of rock and sand debris over Canada and the Northern United States. This glacial debris is responsible for much of the rolling hills dotted with lakes found throughout the northern United States.
Not only did this great ice sheet affect the land, it siphoned water from the surrounding oceans. Scientists estimate that at this time the oceans were as much as two to three hundred feet below their present levels. If correct, the present site of San Francisco would have been nearly fifty miles inland and that of New York City a hundred and fifty miles from the ocean!
As long as conditions were favorable, the ice sheet spread in all directions, growing to an estimated depth of 2,000 to 4,000 feet in what is today New York State and 5,000 feet over New England! An ice sheet that towered a mile high and spread as wide as the continent may seem difficult to believe. However, even today, one tenth of the earth's landmass and 2 percent of the earth's water re mains locked up in glaciers. The Antarctic ice sheet covers more than 5 million square miles at an average depth of a little more than a mile. The glacial ice sheets of today cling to the poles, far from the reach of civilization. However, they provide us with a glimpse of what the giant ancient ice sheets must have been like.
Ultimately, the ice age ended, of course, and the glaciers halted their advance. In response to rising temperatures the ice sheets retreated until they reached an equilibrium with the elements of nature along their present boundaries.
During the early twentieth century, conservative Christians often felt threatened by the thought of an ice age and many even rejected it. They viewed it as an event totally incompatible with a short Biblical chronology. But with the passing of time, as Christian scientists studied the geologic record, most of them concluded that an ice age had in deed existed. They began to realize that the ice age didn't disprove the Bible; it simply showed that the earth's history has been one of turmoil and rapid change.