ERTH 20 Lecture Notes - Lecture 1: Geosphere, Overfishing, Hydrosphere

• School: Irvine Valley College
• Department: Earth Science
• Course: ERTH 20
• Professor: Oliva

Document Summary

Science that studies the whole earth as a system. 4 spheres: atmosphere, mixture of gases, hydrosphere, all of earth"s water, biosphere, anything organic, geosphere solid earth importance of the ocean to earth system. 70% of the world"s surface and 97% of the water. Heat absorption and transport by ocean currents affects climate. 50% of the us population lives on the coast: hazards. Slow down rate of climate change: co2 absorption. Valuable resource but must be exploited sustainably: overfishing, pollution, intro of invasive species to different areas by humans, warming of the oceans due to increased carbon dioxide levels, potential increased storm insensitivity. Cosmic cloud formed from hydrogen, helium, and small amounts of other elements from previous supernovae, gently rotating. Gravity pulls particles close together, rotates more quickly. At the center of the cloud, so much material condenses that nuclear fusion reactions begin ~ 5 billion years ago. The remaining particles continue to move closer together and accrete.