Where did the water in the Oceans come from? Outgassing (H2O, CO2) of the Earth from volcanoes, early in its history, but continuing today Sedimentary rocks as old as billion years!A much smaller amount from comets that pass electrical attraction makes for “sticky” molecules This explains its unique properties: heat capacity surface tension dissolving power | The Properties of Sea Water What makes water so special? Why is the ocean salty? Where’s the Water? Reservoir Volume (106 km3) Percent Ocean 1370 Ice (polar) 29 Groundwater 5 Lakes Atmosphere Rivers Where did the water in the Oceans come from? Outgassing (H2O, CO2) of the Earth from volcanoes, early in its history, but continuing today Sedimentary rocks as old as billion years! A much smaller amount from comets that pass by The Water Molecule Water is a “Polar” Molecule Weak electrical attraction makes for “sticky” molecules This explains its unique properties: heat capacity surface tension dissolving power Temperature vs Heat Temperature is a measure of how fast the molecules in a substance are moving Heat is a measure of how much energy has to be put into (or gotten out of) a substance to change its temperature, or “state” (solid, liquid, gas) Sensible Heat vs Latent Heat Sensible heat is what we sense from different temperatures; energy needed to raise T (or released to decrease T) Latent heat is the energy needed to change state (ice to water, water to vapor) ice water vapor liquid water Exists in three states on the planet surface Changes of state Water co-exists on the Earth in 3 physical states: Habitable Planet solid liquid gas Changes of state always occur at constant temperature The heat needed for a change of state is called latent heat Heat and the three Physical States of Water: Evaporation from lakes, oceans, rivers, etc. occurs for temperatures lower than 100 oC But it requires more energy to do so Energy removed from surface (evaporation) Energy liberated into the atmosphere (condensation) Major source of energy to power the Earth’s weather systems Density of Pure Water Consequences Consequences Bottom temperature of deep, cold lakes is always 4 oC. Ice floats on the water surface, so fish survive. Pipes (or beer bottles) can freeze | The Properties of Sea Water What makes water so special? Why is the ocean salty? Where’s the Water? Reservoir Volume (106 km3) Percent Ocean 1370 Ice (polar) 29 Groundwater 5 Lakes Atmosphere Rivers Where did the water in the Oceans come from? Outgassing (H2O, CO2) of the Earth from volcanoes, early in its history, but continuing today Sedimentary rocks as old as billion years! A much smaller amount from comets that pass by The Water Molecule Water is a “Polar” Molecule Weak electrical attraction makes for “sticky” molecules This explains its unique properties: heat capacity surface tension dissolving power Temperature vs Heat Temperature is a measure of how fast the molecules in a substance are moving Heat is a measure of how much energy has to be put into (or gotten out of) a substance to change its temperature, or “state” (solid, liquid, gas) Sensible Heat vs Latent Heat Sensible heat is what we sense from .
