UNIT 10 WATER

HOW DOES ICE MELT? K.S.

POLAR ICE CAPS T OF C

POLAR ICE CAPS AND HOW THEY MELT

FACTS Glacier-a thick ice mass that forms over many years. Covers nearly 10% of the earths land surface As glaciers move over large areas of bed rock the ice breaks apart making the ice easier to melt If the ice caps melted: -we would lose species like penguins and polar bears that rely on snow for their lives -The sea-level would rise resulting in an increase in the sea-levels -The polar icecaps reflect sunlight, if they were gone, the earth would receive more sunlight and would become warmer

SEASONAL CHANGES Every winter the ice caps expand and every summer they get smaller As the earth changes the polar Ice caps move either towards the sun or away.

GLOBAL WARMING Global Warming -A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse gases One of the most controversial theories as to why glaciers are melting Some sat that humans are destroying the atmosphere by emitting so much carbon dioxide into the air everyday. Destroying the atmosphere means more UV rays from the sun can get through and heat our earth causing the ice to melt Glaciers help prevent Global Warming by reflecting light back into space.

OVERDRAFT Overdraft lowering of the water table beyond the reach of existing wells Wells must be deepened Lowered table causes many issues

SUBSIDENCE Occurs when too much water is pumped causes ground collapse -Looks like craters Ground water is considered last free resource New Orleans is below sea level partly because of subsidence San Jose dropped 13 ft. from over pumping in the first half of the 20 th century

GROUND WATER LEVELS IN RESPONSE TO PRECIPITATION Precipitation soak into the ground (infiltration) -Slowly moves downward then seeps into the ground water Run off is when the rate of rainfall exceeds Earth’s ability to absorb it Plants absorb some water then release to the atmosphere (transpiration)

VOCAB REVIEW Glacier-a thick ice mass that forms over many years. Global Warming -A gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse gases

HOW DOES AN OBJECT MOVE IN WATER? K.S.

IT’S ALL ABOUT WAVES T OF C

OCEAN BASINS Ocean Basins - the depression on the earths surface occupied by the ocean on the surface the lithosphere They take up 30% of the earths surface area Oceans basins are filled with deep grooves called ocean trenches and flat regions known as abyssal plans and volcanic peaks called seamounts. The shape of ocean basins affect the circulation and flow of deep ocean water by creating obstacles and slow moving currents on the floor.

WATER DENSITY DIFFERENCES Water density is affected by water temperature and salinity. As ocean water heats up from the volcanic activity at the ocean floor it becomes less dense and begins rising to the surface creating a circulation of water Salinity – the measure of the salt concentration of water. The more salt in the water the more dense it is. The bottom of the ocean has higher salinity than the surface

CURRENTS Current –the steady flow of surface ocean water in a prevailing direction which are caused by weather, warming and mixing water, westerlies and trade winds. Westerlies degrees latitude, blows west to east. Trade winds-20 degrees latitude, blows east to west. Gulf stream-a warm, swift, north flowing ocean current which begins above the Bahamas, through the Antilles Island becoming a North Atlantic current El Niño – a warm ocean current that flows along the equator from the date line and south off the coast of Ecuador every 4 to 12 years.

CORIOLIS EFFECT Coriolis Effect- the deflective force of Earth’s rotation on all free moving objects, including the atmosphere and oceans. With the enguler effect of the earth (axis) Related to the motion of the object motion of the Earth and latitude.

THE MOON The moon is close the higher the tide. The moon is far the less tides Highest tide in the world –Bay of Fundy in Nova Scotia.

VOCAB REVIEW Ocean Basins - the depression on the earths surface occupied by the ocean on the surface the lithosphere Salinity – the measure of the salt concentration of water. Current –the steady flow of surface ocean water in a prevailing direction which are caused by weather, warming and mixing water, westernlies and trade winds. Gulf stream-a warm, swift, north flowing ocean current which begins above the Bahamas, through the Antilles Island becoming a North Atlantic current El Niño – a warm ocean current that flows along the equator from the date line and south off the coast of Ecuador every 4 to 12 years. Coriolis Effect- the deflective force of Earth’s rotation on all free moving objects, including the atmosphere and oceans.

WHAT IS SALINITY? K.S.

OCEAN LEVELS AND SEDIMENT T OF C

CHANGES IN GLACIER VOLUME “Global warming” causes glaciers to melt, raising sea-levels.3 inch per year. Last recorded “Global warming” episode was 21,000 years ago. In the past 30 years, this trend has begun again

CHANGES IN THE OCEANIC RIDGE SYSTEMS AKA seafloor spreading As the oceanic crust separates rift valleys and sudden drops in elevation occur

SEDIMENT ACCUMULATION Sediments on the sea floor can be sand, volcanic ash, even interstellar dust. They accumulate at varying speeds depending on ocean depth. The accumulation can measure anywhere from.1 mm per year (middle of the ocean) to 1 meter per year along the continents.

TRANSGRESSIVE AND RECESSIVE Sediment sequences on land that are created by the rise and fall of sea level

As sea level gradually rises (transgression), the environment will start as a beach, then become an offshore tide flat, and then a deeper bay with a muddy bottom TRANSGRESSIVE from bottom to top, as the sea transgresses across an area it will leave a sedimentary sequence of sand, then shale and lastly limestone.

As sea level gradually lowers (regression), the sedimentary sequence represents the lowering of sea level and the retreat of the sea from the low-lying land. REGRESSIVE A regressive sequence, from the bottom up would be, limestone, shale, sandstone

VOCAB REVIEW Transgression - a gradual rise in sea level Regression- a gradual lowering in sea level