Reservoirs of Water
Oceans, lakes, rivers, and streams. Ice caps and glaciers. Atmosphere and clouds. Groundwater (in acquifers) and ground ice. Living organisms.
Modes of Water Movement
Precipitation (rain, snow, etc.), evaporation, sublimation, transpiration, flow due to gravity.
Redistribute solar heat in sea water across the Earth; affects Earth's weather and climate.
Current systems involving return flow of cold water to lower latitudes; mainly occurs in large ocean basins.
Colder deep water flows up at coastal areas due to wind energy pushing surface water away from land.
Cold water from polar areas that flows down to sea floor and toward the equator; cold water is colder and more dense.
Saltiness of Water
Due to weathering of rocks on land, and transportation of dissolved elements into the sea; saltiness at present level since ∼3.5 billion years ago.
Removal of Salt from the Ocean
Evaporation of sea water causes saturation and then precipitation of salt crystals, organisms in the sea also take up dissolved minerals.
Residence Time in the Oceans
Each element in sea water stays there an average period of time depending upon how it is usually removed.
Return of salt to the sea
Sediments of the ocean form layers of sedimentary rock that are pushed up into folded mountains, eroded away and transported to the ocean via rivers and streams; subduction may also result in melting of these sediments and chemical return to the ocean via volcanoes.
Effects of Glacial Stages
Sea level drops by ∼250 m due to loss of ocean water as ice caps and glaciers grow. Glaciers move across the land cutting deep U-shaped valleys; glaciers erode and transport vast amounts of soil and rock.
Effects of Interglacial Stages
Sea level rises and shoreline moves inland. Land rises due to removal of weight of ice caps and glaciers. Water takes over as main erosional agent on land; rivers and lakes are re-established.
Milankovitch theory of Ice Ages
Variations in Earth's rotation and orbit ake slight variations in total amount of solar radiation absorbed by Earth's atmosphere; when Precession, Obliquity, and Eccentricity work together.
Milankovitch factor. Change in axial tilt over time from 21.5° - 24.5° over a 41,000 year cycle.
Milankovitch factor. Change in the shape of the Earth's orbit caused by other planet's gravity (∼100,000 years).
Plate Tectonic Control on Ice ages
Glacal stages can occur only when continents are in a high latitude position wher ice caps and glaciers can build up on them; continental position can affect ocean and atmospheric circulation as well.
The effect of rotation of Earth and solar heating. Six main circulation cells, 3 in each hemisphere.
Severe storms that start as low pressure systems over warm ocean water; have cyclonic movement wind 50 to 300 km/hr.
4 to 7 year cycles of weather in Northern hemisphere; due to winds blowing across the Pacific, which affects water circulation patterns in the Pacific basin causing unusually warm waters in equatorial areas and much rain.
Follows large scale reorganization of oceanic and atmospheric circulation (following tectonic plate movement and the growth of mountains. Accompany large changes in global average temperature.
Rocks made of grains and crystals from other rocks; pre-existing rocks must be disintegrated and decomposed (rock weathering) to make materials (sediments) needed to make this type of rock.