17.1: Our Oceans
Our Oceans
Oceans cover 71% of Earth’s surface and hold 97% of Earth’s water, yet nearly 95% of that ocean is completely unexplored. The entire ocean floor has been mapped, but only to a resolution of 3 miles: this means that we can only see features larger than 3 miles wide. We have better maps of the surface of Mars and the moon than we do the bottom of the ocean. We know very, very little about most of the ocean, particularly for the middle and deeper parts far away from the coasts. Why? It is a challenging place to work! In many ways, it is easier to put a person into space than it is to send a person down to the bottom of the ocean. It is dark, cold, and the pressure exerted by the water above is enormous, equivalent to one person trying to support 50 jumbo jets. However, the water that the oceans contain is critical to plate tectonics, volcanism, and of course, life on Earth. The ocean floor is covered with an average of 13,000 feet of water and is pitch black below a few thousand feet or so; it is not easy to discover what is down there. We know a lot more about the oceans than we used to, but there is still a great deal more to discover.
Figure 17.1: Doldrums in the Pacific Ocean (CC-BY 4.0, Chloe Branciforte)
Earth has had oceans for a very long time, dating back to the point where the surface had cooled enough to allow liquid water to condensate, only a few hundred million years after Earth’s formation. At that time there were no continental rocks, so Earth’s water was likely spread out over the surface in one giant (but relatively shallow) ocean.
A person who studies the oceans and coastal processes may have many titles including oceanographer, coastal geomorphologist, sedimentologist, or climate scientist. Like many other geoscientists, working with other disciplines is common, with a heavy influence from both math and technology. Many are employed by universities where they teach and/or do research, and state and federal agencies, including geological surveys, like the California Geological Survey Links to an external site. or United State Geological Survey (USGS) Links to an external site.. Additional career pathways include environmental policy and legislation and consulting, via the private sector or state and federal agencies. Many of these career options require a college degree and postgraduate work. If this pathway is of interest to you, talk to your geology instructor for advice. We recommend completing as many math and science courses as possible. Also, visit National Parks Links to an external site., CA State Parks Links to an external site., museums, gem & mineral shows, or join a local rock and mineral club. Typically, natural history museums will have wonderful displays of rocks, including those from your local region. Here in California, there are a number of large collections, including the San Diego Natural History Museum Links to an external site., Natural History Museum of Los Angeles County Links to an external site., Santa Barbara Museum of Natural History Links to an external site., and Kimball Natural History Museum Links to an external site.. Many colleges and universities also have their own collections/museums.