Ch 6 - Earth and Space The Hydrosphere

Hydrosphere The hydrosphere is the part of the Earth that contains water in all its states: liquid, solid, and gas Lakes, rivers, oceans, glaciers, etc. 97.5% of all water is salt water 2.5% of all water is fresh water Of this 2.5%, 79% of fresh water is trapped and frozen in glaciers 21% of freshwater is available as lakes, rivers and ground water

Inland Water Def’n: Bodies of freshwater found on continents. Contains rivers, lakes and groundwater. The study of these different waters is divided into catchment areas or watersheds

Catchment Area - Watersheds Def’n: A part of land where all inland waters will drain and flow into the same larger body of water Also called drainage basin

Pollutants More catchment areas a river has, the more polluted the water can become.

Aspects which affect a watershed How easily can water flow across a surface? Topography: natural and artificial features of the area Geology: rocks Climate Vegetation Agriculture

Cryosphere Def’n: The crysophere consists of all frozen water on the Earth’s surface Pack ice, glaciers, frozen lakes and rivers, snow and permafrost Cryo from Greek meaning icy cold

Pack Ice Huge slabs of ice floating on water. Smaller, free-floating sheets of ice are called ice floes. Generally found in the Artic Ocean near Russia and around Antartica Content and location: freshwater, floating in water

Shrinking

Glaciers A mass of ice on land, formed by compressed snow Large glaciers are called ice caps or ice sheets Note: 79% of freshwater is contained in glaciers Content and location: freshwater, on land

Icebergs (enrichment) A piece of a glacier that has broken off and floats into open water Breaking off: https://www.youtube.com/watch?v=a6bgTCdkfTM It can melt away or can freeze into pack ice Iceberg flipping over: https://www.youtube.com/watch?v=Sh271FAVZ0o

Oceans The study of oceans involves two important parameters: Why? Water temperature Salinity Why? They influence ocean circulation

Ocean Circulation The Gulf Stream Explained https://www.youtube.com/watch?v=UuGrBhK2c7U

The Ocean Large masses of salt water Two types of currents Surface currents: driven mostly by wind Subsurface currents (deep currents) aka thermohaline circulation: driven by water density differences due to temperature and water

Surface Currents About 400 m deep : Gulfstream Wind driven Affected by rotation of the Earth

Subsurface Currents – Thermohaline Circurlation Caused by density of water Huge conveyer belt that connects surface and subsurface Distributes heat around the world

Water temperature is influenced by: Latitude Where the ocean is located on the Earth relative to the equator influences the average temperature. Map of surface temperatures. Red = warmer. Blue = cooler Approx. 25-29°C near the equator Approx. 12-17°C in temperate zones

Factors that Affect Ocean Circulation Subsurface currents are driven by differences in density due to temperature and salinity. Cold water is denser and sinks Warm water is lighter and rises Salt differences Salty water is denser and sinks Less salty water is less dense and rises https://youtu.be/WEDUtS0IMws?t=42s

Polar Equator

Most dense water: Cold and salty Less dense water: Warm and less salty

Pack Ice + Glaciers? As the ice melts, the water is less salty which makes it less dense. The water will no longer sink to the bottom.

A) Location 1 will be the most affected, since the flow of water will carry the toxic substance into the lake. B) Location 2 will be only slightly affected, since the current will prevent the toxic substance from accumulating. C) Because of the terrain, only location 3 will be affected. D) Location 4 will be affected the most, since it is downstream from the spill