1. AND THEIR RELATION TO OCEAN

2. Earth is made up of different layers which are classified as: Lithosphere - solid component of Earth. Hydrosphere – water phases at the surface of Earth. Atmosphere – air component within 50km of surface. Magnetosphere – outermost region which extends into the space. Biosphere – part of earth containing life and extends 8-10km above and below the sea level.

3. Lithosphere (solid component) of earth is further divided into three major layers: Inner core: 1300km radius Outer core: 1300-3500km radius Mantle: 3500-6500km radius Crust: outermost layer. 5-50km.

4. The major composition of solid earth includes following elements: Iron: 34.6% Oxygen: 29.5% Silicon: 15.2% Magnesium: 12.7% Nickel: 2.4% Sulfur: 1.9% Titanium: 0.05%

5. Earth is third planet of the solar system, is round/spherical in shape and has following properties: Rotation period: 23hr 56min 4sec Mass: 5.98x10 24 kg Diameter: 12,754km Density: 5.5 g/cm 3 Surface gravity: 9.8 m/sec 2 Escape velocity: 11.2km/sec Surface area: 5.1x10 8 km 2 Surface temperature: 200K-300K(-100 to 117˚F) Atmospheric pressure: 1.00bar

6. DEEP SEA VENTS THEORY: About two decades ago, this theory about origin of life on earth was originated which assumes that the live emerged from the earlier organisms living in seafloor hot springs. As scientists discovered unexpected communities living in seafloor hydrothermal vents which lived on a chemical rich in hydrogen, carbon dioxide and sulfur from the hot geysers, they proposed that the hydrothermal vents provided an ideal environment for the microbial life to emerge on earth. Scientists believe that the chemical “methanethiol” which is present in many organisms as the starting chemical for the origin of life on earth.

7. Today’s technology allows us to explore the areas and oceans of world in more convenient and technical way. The technologies used in ocean explorations include: Vessels: for collection of weather and other observations. Submersibles: For deep seafloors not safe for divers Observation systems and sensors: To observe sea components, temperature, shape of sea etc. Communication technologies: Helps scientists to collect and transmit information quickly and efficiently. Diving technologies: To explore the sea with human eye in safe conditions.

8. The Living Cosmos: Our Search for Life in the Universe (Hardcover) by Chris Impey The Living Cosmos: Our Search for Life in the Universe (Hardcover)Chris Impey Essentials of Oceanography (11th Edition) by Alan P. Trujillo and Harold V. Thurman Essentials of Oceanography (11th Edition)Alan P. Trujillo