Physical Oceanography
From Period 7 Students in Dr. Durkin’s 10th Grade Earth Science Class
From Period 5 Students in Dr. Durkin’s 10th Grade Earth Science Class
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From Period 7 Students in Dr. Durkin’s 10th Grade Earth Science Class
From Period 5 Students in Dr. Durkin’s 10th Grade Earth Science Class
In response to “How much water is on the Earth?”
As you may have heard, 70% of the earth is covered by water! The ocean holds 96.5% of all the earth’s water, but there is also water in the air, in the soil, underground, in glaciers, and in ice sheets, such as Antarctica and Greenland. Even though most of the earth is covered with water, its actually only a thin layer relative to the size of the earth, like a sheet of paper! This article has some nice figures and more explanations: https://www.usgs.gov/special-topic/water-science-school/science/how-much-water-there-earth?qt-science_center_objects=0#qt-science_center_objects.
In response to “Do we really know about only 5% of the ocean?”
Following on Joe Pedlosky’s comment, its true that we have a very good general idea of how large ocean currents work. In fact, we can measure most of the ocean’s surface currents and temperature from space, and have fleets of robots called Argo floats that measure water temperature and salinity around the world. However, observations of the ocean beneath 2000m (about half of the ocean!) are still very rare. Also, in terms of organisms and chemical properties, we have a lot fewer observations even in the shallow parts of the ocean.
In response to “How does wind create the currents in the ocean?”
Because of the rotation of the earth, the wind actually pushes the water near the surface of the ocean to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This way, water actually piles up in different locations, which sustains currents that flow around these “hills” and “valleys”, again because of the rotation of the earth. In the end, most large currents flow in the same direction as the wind unless there is a coastline, which complicates things even more. As you can see, this is a large area of study!