Ch. 19 The Ocean Basins Sect. 19.1. Oceanography The study of the physical characteristics, chemical...
-
Upload
eli-bestwick -
Category
Documents
-
view
215 -
download
0
Transcript of Ch. 19 The Ocean Basins Sect. 19.1. Oceanography The study of the physical characteristics, chemical...
Ch. 19 The Ocean Basins
Sect. 19.1
Oceanography• The study of the
physical characteristics, chemical composition and life forms of the ocean
• Matthew F. Maury - began early study in 1850’s using records from navy ships
Why Study Oceanography
• To Feed Us - Aquaculture
• To predict weather
• Mineral Resources
Global Ocean
• Covers 3/4 of the earth’s surface (this is the most prominent feature on Earth!)
• contains 97% of all the water on the earth
• Totals 1/800 of Earth’s total volume
• 5 oceans: Pacific, Atlantic, Indian, Arctic and Southern (Antarctic)
• smaller areas of the oceans are called seas
Pacific Ocean
• Largest, Deepest (contains more than ½ the ocean water)
• Has many trenches and few abyssal planes
• Ring of Fire
• Deepest Trench-Mariana Trench
Atlantic• 2’nd largest ocean• Shallowest (avg. depth
3.9km)• Many sea routes
between eastern and western hemispheres
Indian Ocean• 3’rd largest• less than 1/2 the size of
the Pacific• Contains many ridges• Monsoons
Southern Ocean (Antarctic Ocean)• Coldest• Least Salty• Extends from the tip
of Antarctica to 60 degrees South latitude
• Contains largest current
Arctic Ocean
• Smallest• Mostly surrounded by
land• Central part permanently
covered with ice and surrounded by water in summer.
• Completely frozen in winter
Technology in Ocean Exploration
• Drilling Ships
• JOIDES Resolution
• Take Core samples
Submersibles
• Underwater research vessels including the following:
Bathysphere
• One of the first that was linked to the surface with a cable
Bathyscaph• Self-propelled
• Free-moving
• Alvin and Nautile
Alvin
Robotics
• Argo and Jason Jr• Used to discover the
Titanic
Size of Jason Junior
SONAR
• Sound Navigation and Ranging
• consists of a transmitter and receiver
• sound waves are used to map and make profiles of the ocean floor
** Transmitter sends out sound waves @ 1500 m/s
** Sound waves are reflected back to receiver
** The time elapsed gives depth or distance:
Speed = Distance Time
Distance = Speed x time
Time = Distance Speed
……it would it would take take 125 125 yearsyears to to totally map totally map the ocean the ocean floor using floor using sonar…sonar…
…these days we can use satellite altimetry!
• The bumps & dips on the ocean’s surface mimic the topography of the ocean floor.
• SEASAT (and later GEOSAT) circle the earth; their sensitive radar altimeters send data used to create ocean floor maps.