Sirach 43:20

This winter and the next were the coldest in Nazareth for many decades. Jesus had seen snow on the mountains, and several times it had fallen in Nazareth, remaining on the ground only a short time; but not until this winter had he seen ice. The fact that water could be had as a solid, a liquid, and a vapor — he had long pondered over the escaping steam from the boiling pots — caused the lad to think a great deal about the physical world and its constitution; and yet the personality embodied in this growing youth was all this while the actual creator and organizer of all these things throughout a far-flung universe.

The northern regions of this world have experienced six separate and distinct ice invasions, although there were scores of advances and recessions associated with the activity of each individual ice sheet. The ice in North America collected in two and, later, three centers. Greenland was covered, and Iceland was completely buried beneath the ice flow. In Europe the ice at various times covered the British Isles excepting the coast of southern England, and it overspread western Europe down to France.

Simultaneously with these land elevations the ocean currents shifted, and the seasonal winds changed their direction. These conditions eventually produced an almost constant precipitation of moisture from the movement of the heavily saturated atmosphere over the northern highlands. Snow began to fall on these elevated and therefore cool regions, and it continued to fall until it had attained a depth of 20,000 feet. The areas of the greatest depth of snow, together with altitude, determined the central points of subsequent glacial pressure flows. And the ice age persisted just as long as this excessive precipitation continued to cover these northern highlands with this enormous mantle of snow, which soon metamorphosed into solid but creeping ice.

While the tribes of the north grew more and more to fear the ice, those living near the homeland of their origin became exceedingly fearful of the water. They observed the Mesopotamian peninsula gradually sinking into the ocean, and though it emerged several times, the traditions of these primitive races grew up around the dangers of the sea and the fear of periodic engulfment. And this fear, together with their experience with river floods, explains why they sought out the highlands as a safe place in which to live.

Throughout the glacial period other activities were in progress, but the action of the ice overshadows all other phenomena in the northern latitudes. No other terrestrial activity leaves such characteristic evidence on the topography. The distinctive boulders and surface cleavages, such as potholes, lakes, displaced stone, and rock flour, are to be found in connection with no other phenomenon in nature. The ice is also responsible for those gentle swells, or surface undulations, known as drumlins. And a glacier, as it advances, displaces rivers and changes the whole face of the earth. Glaciers alone leave behind them those telltale drifts — the ground, lateral, and terminal moraines. These drifts, particularly the ground moraines, extend from the eastern seaboard north and westward in North America and are found in Europe and Siberia.

The Iceland land bridge submerged, and the arctic waters commingled with those of the Atlantic Ocean. The Atlantic coast of North America rapidly cooled, but the Pacific coast remained warmer than at present. The great ocean currents were in function and affected climate much as they do today.

The same polar sea that extended so far down over North America likewise covered all of South America except the soon appearing Andes Mountains. Most of China and Russia was inundated, but the water invasion was greatest in Europe. It was during this submergence that the beautiful lithographic stone of southern Germany was laid down, those strata in which fossils, such as the most delicate wings of olden insects, are preserved as of but yesterday.

Gradually the inland lakes and seas were drying up all over the world. Isolated mountain and regional glaciers began to appear, especially over the Southern Hemisphere, and in many regions the glacial deposit of these local ice formations may be found even among some of the upper and later coal deposits. Two new climatic factors appeared — glaciation and aridity. Many of the earth’s higher regions had become arid and barren.

The oceanic climate remained mild and uniform, and the warm seas bathed the shores of the polar lands. Brachiopod and other marine-life fossils may be found in these deposits right up to the North Pole. Gastropods, brachiopods, sponges, and reef-making corals continued to increase.

Away from the ice the land and water life of the world was little changed. Between the ice invasions the climate was about as mild as at present, perhaps a little warmer. The glaciers were, after all, local phenomena, though they spread out to cover enormous areas. The coastwise climate varied greatly between the times of glacial inaction and those times when enormous icebergs were sliding off the coast of Maine into the Atlantic, slipping out through Puget Sound into the Pacific, and thundering down Norwegian fiords into the North Sea.