Ancient stories about a great flood covering the Earth have come to us from various cultures around the world. Perhaps the most well-known in the west is the Biblical story of Noah. In Greek mythology there is also a deluge story where only Deucalion (Prometheus’ son) and Pyrrha (Pandora’s daughter) are saved. In both accounts the respective deity in power floods the Earth, saving only the faithful. Similarly, the endings to these stories offer hope as the world is renewed and a new “family” of humankind begins: Noah’s sons venture forth to father new cultures—Shem becomes the father of the Semitic people, his brother Ham, the father of African nations, and so forth; Deucalion and Pyrrha veil their heads and cast behind them “the bones of their mother”—Mother Earth, that is—and in so doing, the stones (her bones) take human form as they fall, becoming the first inhabitants of the Stone Age. While Charles Darwin undoubtedly would have had a difficult time accepting these inventions as the evolution of man, the cataclysmic event of global flooding tearing the Earth asunder is not so far off the mark. (Although, according to Dr. Turekian, Darwin didn’t pay much attention to the paleontologic evidence of his day either.) Yet, as Dr. Turekian also points out: “Before the identification of characteristic glacially induced features, these [recent unconsolidated sedimentary] deposits were perceived to be relicts of the great flood recording in the Bible associated with the story of Noah and the ark.” (“Temperature Variation Over Time,”
Global Environmental Change,
page 73.)
Students will share in an oral reading of the stories of “Pandora” and “Deucalion” from D’Aulaire’s
Book of Greek Myths
(pages 74-79), followed by a discussion about flood myths and facts. To illustrate the process of glaciation, I will review with the class the section on “Glaciers” from
The Big Book of The Earth
picture book (pages 46-47). In this regard, we will also discuss the geologic history of Long Island Sound (which students will be studying in Science class, and for some, in Reading or Study Skills class as well). During this presentation, we will review that starting about 2.5 million years ago, continental ice sheets began to grow and wane, spreading out across North America and Europe. As glaciers moved from their areas of accumulation, these enormous rivers of ice ground their way across the terrain carrying rock-laden loads (with everything from boulders to tiny particles of clay). As the glaciers moved southward and began to retreat by virtue of the melting at their southern ends, they left behind till (rocks and soil deposited directly from a glacier), which at the terminus of the glacier formed ridges called moraines. Long Island is an example of the effects of glaciation with its terminal moraines, Ronkonkoma and Harbor Hill. The basin situated between these moraines and the coastline of Connecticut filled with water and became a glacial lake. As sea level rose from melting glaciers, salt water overflowed into the lake, wearing away at the eastern end and eventually clearing a second opening near New York City. Thus Long Island Sound became an arm of the sea; the estuary it is today.
Referring back to our flood myth and the Odyssey as well, I will further point out that rising sea level as the result of melting glaciers also flooded coastal areas, forming large bays, such as the Persian Gulf. An example on a smaller scale is the ancient harbor of Troy, which eventually silted up (as mentioned in a quote by Dr. Turekian in “Lesson Five: Stormy Weather”). Looking to Odysseus’ journey from Ithaca to Troy and eventually back again, one might consider the flooding that had taken place to make the setting for this story possible, since Odysseus had to wander about for quite some time in the Aegean Sea, the waters of which occupy a graben (an area of land that had dropped down between faults). The topography of Greece, a product of tectonic forces—with its southern coasts situated very near to where the Eurasian and African plates meet today—is the result of major faulting that had thrust some lands higher and caused others to sink, resulting in its abundance of mountains, narrow coastal plains and 1450 islands (several of which Odysseus managed to escape from).
Owing to space-age technology, we have been able to view our planet from high above Earth’s atmosphere and to witness a vast ocean covering most of its surface, and with its dispersed cloud cover, making it appear like a blue marble. Intuitively, the Greeks must have shared this view in their belief of Oceanus, the legendary ocean-river that ran past the Straits of Gibraltar to encompass the world; and of which Homer, with no small degree of prescience, believed to be the source of all things, including the gods. (Darwin may have found this idea a tad more palpable.) Using illustrations from the eighth grade science text,
Dynamic Earth,
regarding continental drift and plate tectonics, I will show that the world’s oceans are, in fact, one great ocean-river, whose circular flowing currents form a continuous worldwide pattern of circulation. Perhaps it is easier to envision a world ocean by looking back 250 million years when the major continents of Earth converged into the mega continent, Pangaea, which was surrounded by ocean. After 50 million years, Pangaea began a long labor that would give birth to the world we know today. In that process, convection currents within the Earth’s mantle created new divergent boundaries as rising magma weakened continental areas resulting in rift valleys. The V-shaped rift valleys subsequently filled with water and the lava eruptions that came up through their bases, cooled at the surface, leveling in new ocean floor. 115 million years after its formation, Pangaea diverged into three continents: North America, Eurasia, and Gondwanaland. 35 million years after that, Gondwanaland diverged into South America, Africa, India and Anarctica-Australia. 45 millions years ago, Europe broke free from Asia and Australia broke free from Antarctica. From that time forward, Europe and Asia converged again and connected with the north-eastern portion of Africa; North and South America became linked by what we now call Mesoamerica, and India collided into the Eurasian plate, which literally gave rise to the Himalayas (17 million years ago). In this long process of diverging and converging land masses, the major oceans of the world were formed.
At the end of this presentation, students will engage in a discussion about what the future will be like 250 million years from now when most of the Earth’s continents may once again form into a mega continent surrounded by water, and with a new ocean in its center and the Antarctica/Australia continent not far off its southern coast. (
Dynamic Earth,
page 72.) Lastly, we will practice presentation skills by students taking turns to narrate the geological history of Long Island Sound (the text to be taken from
The Soundbook
introductory section, pages 10-11). This activity will be fine-tuned later on to be included in our curricular team’s culminating activity of the town meeting.
