Oceans and Coastlines. Shown is a foggy coastline along the Kuril Islands, Russia. Oceans and Coastlines. Shown is a foggy coastline along the Kuril Islands, Russia. Fig. 16-CO, p.376

The oceans of the world. The “seven seas” are the North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, Arctic and Antarctic (related to commerce). Geologists recognize four major ocean basins: the Atlantic, Pacific, Indian and Arctic. The Pacific is the largest, and covers 1/3 of the Earth’s surface. The oceans of the world. The “seven seas” are the North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, Arctic and Antarctic (related to commerce). Geologists recognize four major ocean basins: the Atlantic, Pacific, Indian and Arctic. The Pacific is the largest, and covers 1/3 of the Earth’s surface. Fig. 16-1, p.378

Arctic Ocean. Arctic Ocean. Fig. 16-2, p.378

Sea Water Sea Water Salinity: the total quantity of dissolved salts expressed as a %. It refers to all dissolved ions, which make up about 3.5% of the weight of ocean water. The six main ions are shown. Sea water also has dissolved gases, like CO2 (greenhouse gas) and oxygen (needed by marine organisms). Salinity: the total quantity of dissolved salts expressed as a %. It refers to all dissolved ions, which make up about 3.5% of the weight of ocean water. The six main ions are shown. Sea water also has dissolved gases, like CO2 (greenhouse gas) and oxygen (needed by marine organisms). Fig. 16-3, p.378

The salinity of the surface of the central oceans changes with latitude. At the equator, high rainfall dilutes it to 3.45%; but in places where evaporation is high and precipitation is low (dry, subtropical areas) salinity is high (3.6%). It also varies along coastlines (for example, large freshwater rivers along the Baltic Sea, along with rain and snow, dilute sea water to a salinity is 2%). The salinity of the surface of the central oceans changes with latitude. At the equator, high rainfall dilutes it to 3.45%; but in places where evaporation is high and precipitation is low (dry, subtropical areas) salinity is high (3.6%). It also varies along coastlines (for example, large freshwater rivers along the Baltic Sea, along with rain and snow, dilute sea water to a salinity is 2%). Fig. 16-4, p.379

The world’s rivers carry more than 2.5 billion tons of dissolved salts to the oceans annually. Underwater volcanoes contribute additional ions. However, salinity of the oceans remains relatively constant…why? The world’s rivers carry more than 2.5 billion tons of dissolved salts to the oceans annually. Underwater volcanoes contribute additional ions. However, salinity of the oceans remains relatively constant…why?

Temperature: there are three temperature layers in the ocean. The surface depth to about 450 meters is warm, temperature cools rapidly with depth in the thermocline (to 2 km), and the ocean depths are cold (1-2.5 degrees C). Temperature: there are three temperature layers in the ocean. The surface depth to about 450 meters is warm, temperature cools rapidly with depth in the thermocline (to 2 km), and the ocean depths are cold (1-2.5 degrees C). Fig. 16-5, p.379

Tides: The Moon’s gravity causes a high tide at point A located directly under the Moon. The motion of the Earth-Moon system causes a high tide at point B, opposite to point A. Tides: The Moon’s gravity causes a high tide at point A located directly under the Moon. The motion of the Earth-Moon system causes a high tide at point B, opposite to point A. Most coastlines experience two high tides and two low tides during an interval of about 24 hr, 53 min. Most coastlines experience two high tides and two low tides during an interval of about 24 hr, 53 min. Why is there a high tide at point A? The Earth and Moon orbit a common center of gravity. Why is there a high tide at point A? The Earth and Moon orbit a common center of gravity. Fig. 16-6, p.380

Why the 53 minutes? Why the 53 minutes? Fig. 16-7, p.382

Fig. 16-8, p.382

Low tide, Bay of Fundy, Nova Scotia. Low tide, Bay of Fundy, Nova Scotia. Fig. 16-9a, p.383

High tide, Bay of Fundy, Nova Scotia. High tide, Bay of Fundy, Nova Scotia. Fig. 16-9b, p.383

Terminology used to describe a wave. Sea Waves develop by wind blowing across water. Terminology used to describe a wave. Sea Waves develop by wind blowing across water. Fig , p.383

While a wave moves across the sea surface, the water itself moves only in small circles. While a wave moves across the sea surface, the water itself moves only in small circles. Fig , p.383

Ocean Currents: major ocean currents of the world are shown. Unlike sea waves, a current is a continuous flow of water in a particular direction. Ocean Currents: major ocean currents of the world are shown. Unlike sea waves, a current is a continuous flow of water in a particular direction. Surface Currents: wind-driven, drags surface water with it (usually in prevailing wind direction). Have profound affect on climate; the Gulf Stream (80 km wide and 650 meters deep off Florida, moving at 5 km/hr), for example, transports warm water northward, warming NA and Europe. Surface Currents: wind-driven, drags surface water with it (usually in prevailing wind direction). Have profound affect on climate; the Gulf Stream (80 km wide and 650 meters deep off Florida, moving at 5 km/hr), for example, transports warm water northward, warming NA and Europe. Fig , p.384

Coriolis Effect on Ocean Currents: OC move in circular paths called gyres. These rotate CW in the NH, and CCW in the SH. Why? Coriolis Effect on Ocean Currents: OC move in circular paths called gyres. These rotate CW in the NH, and CCW in the SH. Why? When a person on a moving skateboard throws a ball, it arcs in the direction of motion. When a person on a moving skateboard throws a ball, it arcs in the direction of motion. Fig , p.385

The Coriolis effect can be demonstrated on a merry-go- round. Person on rim is analogous to a person at the equator; and person at center is analogous to person at a pole. The ball arcs in the direction of rotation. The Coriolis effect can be demonstrated on a merry-go- round. Person on rim is analogous to a person at the equator; and person at center is analogous to person at a pole. The ball arcs in the direction of rotation. Fig , p.385

The Coriolis effect deflects water and wind currents. Water or air moving poleward from the equator is traveling east faster than the land beneath it and veers to the east (turns right in NH, and left in SH). What about water or air traveling from the North Pole toward the equator? The Coriolis effect deflects water and wind currents. Water or air moving poleward from the equator is traveling east faster than the land beneath it and veers to the east (turns right in NH, and left in SH). What about water or air traveling from the North Pole toward the equator? Fig , p.386

Deep Sea Currents: not driven by wind, but by differences in water density. Dense water sinks and flows horizontally along the sea floor; it becomes dense by cooling or rising salinity. The Gulf Stream, for example, originates in the subtropics, flows north, cools and sinks near Greenland, reaches the sea floor, deflects southward to form the North Atlantic Deep Water which flows along the seafloor all the way to the Antarctic. Above is profile of AO. Deep Sea Currents: not driven by wind, but by differences in water density. Dense water sinks and flows horizontally along the sea floor; it becomes dense by cooling or rising salinity. The Gulf Stream, for example, originates in the subtropics, flows north, cools and sinks near Greenland, reaches the sea floor, deflects southward to form the North Atlantic Deep Water which flows along the seafloor all the way to the Antarctic. Above is profile of AO. Fig , p.387

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Sea level has fluctuated more than 150 meters during the past 40,000 years, primarily in response to growth and melting of glaciers. Today, sea level is rising at about 2 mm/yr. Global warming melts glaciers and heated water expands. Sea level has fluctuated more than 150 meters during the past 40,000 years, primarily in response to growth and melting of glaciers. Today, sea level is rising at about 2 mm/yr. Global warming melts glaciers and heated water expands. Fig , p.401

A 1-meter sea-level rise would flood 17% of Bangledesh and displace 38 million people. Could this happen? A 1-meter sea-level rise would flood 17% of Bangledesh and displace 38 million people. Could this happen? Fig , p.402

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