EDUCATOR'S GUIDE: SEA CHANGE, The Seascape in Contemporary Photography


~ Oceans cover about 7/10 of our planet yet once there were no seas at all. Scientists believe that about 3,500 million years ago the earth was very hot and surrounded by steam. As the earth cooled so did the steam around it forming water that made seas in the hollows of the earth.

~ By volume, the oceans make up 99% of the planet s living space - the largest space in our universe known to be inhabited by living organisms. Marine plants and animals are used in scores of products, including food, medicine, ice cream, toothpaste, fertilizers, gasoline, cosmetics, and livestock feed.

Doug and Mike Starn (United States, born 1961)
Ocean in Fog, 1996
Toned gelatin silver print, scotch tape
Collection of the artists
©1998 Doug and Mike Starn

~ The earth has more than 20 seas and four oceans: Atlantic, Indian, Arctic, and Pacific, the last being the oldest, largest and deepest. While the average depth of the ocean is about two miles, the Pacific s Mariana Trench is over six miles deep. Note: Mt. Everest is five miles high.

~ Ocean waters are constantly on the move. The earth s oceans are joined and you can travel from one to the other without crossing any land. This, along with currents and tides, is one reason why messages in bottles are sometimes found thousands of miles from where they were thrown in the sea. Because all oceans are joined, the water reaches about the same height all the way around the world. This height is called sea level.

~ Oceans help determine climate and play a critical role in people s ability to live on earth. Ocean currents - rivers of water flowing through the sea - happen because warm water moves away from the equator and cooler water from the Poles flows in to take its place. Currents and weather patterns are directly connected through the process of evaporation which is a key factor in the amount of rain we receive.

~ El Nino - the periodic warming of tropical waters along the equator in the Pacific Ocean -recently made news because it drastically affected weather patterns across the planet. It is difficult to imagine that a change in the temperature of an ocean can affect weather across the world. Energized by El Nino s warm water, normal weather systems produced stronger and more numerous storms in California, which caused power outages and deaths from floods and mudslides. Other El Nino-related changes in weather were unusually warm temperatures in the northern and eastern United States, tornados in Florida, droughts and wildfires in Borneo, and a crisis in northern Tibet, where it snowed for several months without stopping.

James Welling
Seascape F, 1991
UltraStable print
Courtesy of the artist and Jay Gorney Modern Art, New York
©1998 James Welling

~All over the world the sea moves regularly in over the shore and then out again. This movement, called the tide, is primarily caused by gravitational pull from the sun and the moon. The pulling effect on the seas creates high and low tide, and most seashores have two high tides and two low tides every day.

~ Winds traveling across the ocean create waves. The stronger the wind, the bigger the waves.

~The tallest wave ever recorded - 116 feet high - was seen in 1933 by sailors on a U.S. naval ship in the Pacific Ocean.

~ Seas are salty because rivers dissolve chemicals, such as salt, out of the rocks and wash them into the ocean. The saltier the sea, the easier it is to float in it. The Red Sea is the saltiest sea.

~ The oceans help shape the land by pounding away at the seashore. They hammer against dirt and rock cliffs and slowly wash them away. In some places land is being worn away so quickly that walls are built to protect it.

~ Islands are the tops of underwater mountains or volcanos that rise up above the level of the sea. If all the water in the seas could be drained away, some of the mountains would be twice as high as Mt. Everest.

~ Over 90 % of international trade is carried by ships. Much of the communications between continents use underwater cables. Many battles between nations have been fought on or under the sea.

~ The oceans have an important effect on our lifestyle. Besides affecting weather and climate, they provide us with food, water, transportation, recreation, and eventually, receive our wastes.

~ Polluted oceans hold hidden dangers for everyone. More than 3/4 of coastal pollution originates on land from coastal development and industry wastes, automobile exhaust and carelessness. Oil spills, sewage dumping and over-fishing also threaten open waters.

Lynn Davis
Evening/Northumberland Strait, #IV, 1993
Seleniumtoned gelatin silver print
Courtesy of the artist and Edwynn Houk Gallery, New York
©1998 Lynn Davis

~ Scientists believe that all life evolved from the sea.

~ The melting of polar ice due to global warming and the wearing away of the seashore contribute to an increase of water and a decrease of land on our planet, a particular threat to island peoples.

Ocean Facts is adapted with permission from the web site for the Woods Hole Oceanographic Institution Sea Grant Program.

HOME    This page last updated July 27, 1999.

Center for Creative Photography · The University of Arizona · Tucson, Arizona 85721-0103 · Phone: 520-621-7968