Marine science is to study the natural phenomena, properties and changing laws of the ocean, and the knowledge system related to the development and utilization of the ocean. Its research object is the ocean that accounts for 7 1% of the earth's surface, including seawater, substances dissolved and suspended in seawater, creatures living in the ocean, seabed sediments and seabed lithosphere, as well as the atmospheric boundary layer and estuary coastal zone on the sea surface. Therefore, marine science is an important part of earth science.
research objects
Among the planets in the solar system, the earth is in a unique position. The size and mass of the earth, the distance between the earth and the sun, the earth's orbit around the sun and the rotation period interact well, making the average temperature in most parts of the earth's surface moderate (about 15℃).
As a result, there are three kinds of water (liquid, solid and gaseous) on its surface at the same time, and most of the water on the earth gathers in the ocean in the form of liquid seawater, forming a global-scale saltwater body-the world ocean. The earth is the only planet in the solar system with oceans. Therefore, our earth is also called "the planet of water".
The global ocean area is about 360 million square kilometers, accounting for 7 1% of the total surface area, equivalent to 2.5 times the land area. The average depth of the global ocean is about 3800 meters, and the maximum depth is 1 1034 meters. The average depth of the main parts of the Pacific Ocean, the Atlantic Ocean and the Indian Ocean all exceeds 4,000 meters. The volume of the global ocean is about 65.438+0.37 billion cubic kilometers, which is equivalent to more than 97% of the total water volume of the earth.
The above contents refer to Baidu Encyclopedia-Nanjing University of Information Science & Technology.