Do Now: Look at the following images. How are they alike and how are they different? Where are they typically located on this planet?

Aim: How does the water on this planet differ? What type of water occurs naturally?

Hydrosphere 75% of earth is covered by water Most of this water is saltwater!

Most of the Earth Is Covered With Water Saltwater: global ocean divided into 4 areas –Atlantic –Pacific –Arctic –Indian Freshwater

Salinity Salinity refers to the amount of minerals dissolved in water Global oceans average salinity= 35ppt or 3.5% FACTOIDS: DEMO –For every 1 liter of sea water, there are 35 grams of salts dissolved in it –One cubic foot of sea water would evaporate to leave 1 kg of sea salt

Seawater salinity Varies through out the earth. Also varies with depth because seawater is heavier than fresh water due to increase in minerals it sinks 1. Lower salinity occurs in places like river mouths & coastal areas due to fresh water run off –Freshest seawater = Gulf of Finland (Part of the Baltic Sea) 2. Higher salinity occurs in places with high temps & confined/low circulation –Result in high rates of surface evaporation –Most saline open sea = Red Sea

Sea water Composition Seawater contains every known element found on earth to some extent. Number one element? Chlorine Next? Sodium

Freshwater Composition Contains minimal quantities of dissolved salts All ultimately comes from precipitation of atmospheric water vapor

How are the hydrosphere and lithosphere connected? Pause…Write …

What is a river?

A river is a natural watercourse usually freshwater flowing towards an ocean a lake a sea or another river.

Life of a River 1. Water falls to Earth in the form of precipitation (rain, snow, etc) and does NOT go through the soil to become groundwater 2. Instead, this water travels along Earth ’ s surface via gravity 3. This eventually forms a small stream, which grows into a larger stream 4. Eventually this stream grows to become a river as more water is added to the stream 5. This river will flow until it reaches an ocean Precipitation  Stream  River  Ocean

Watershed (drainage basin) Land area that drains into a particular stream As water moves into streams it carries sediments and other dissolved substances including small amounts of oxygen Head waters- source of stream, usually turbulent and laden with oxygen and carbon dioxide Rule of thumb- increase turbulence, increase dissolved gases in water

Watershed

Freshwater Bodies: a Weathering Factor The movement of water on land is largely responsible for shaping Earth’s surface Water follows the lowest topographical path and etches channels in rocks –the eroded material gets carried farther downstream As water travels around bends, it loses its velocity & drops some of its sedimentary load Delta: landform of deposited sediments where rivers meet the ocean and drop sedimentary load because of a decrease in velocity –This land has rich, fertile land due to mineral deposition pg177

Can you guess where this Delta is located?

Estuary Where the “arm” of a sea extends inland to meet the mouth of a river –Sea water moves inward mixing with fresh river water resulting in brackish water High in nutrients and sediments Shallow water, high sunlight Rich in both plant and animal life Commercially important marine life use estuaries as a nursery for their eggs Types: Salt water marsh, Mangrove forest, Inlets, & Bays

Estuary

Pic: Salt Marsh & Food Web Salt marsh

Pic: Mangrove Forest Mangrove forest

Wetlands Among the most diverse ecosystems Found along the shores of fresh bodies of water Types: –Marshes –Swamps –Bogs –Prairies potholes (seasonal) –Flood plains (occur when excess water flows out of the banks of river into a flat valley)

Saltwater Ecosystem: Barrier islands Important source of biodiversity Land form off coastal shores created by the build up of deposited sediments Boundaries are constantly shifting as water moves around them Important buffer for the shoreline behind them when offshore storms hit

Pic: Island Barrier

Tropical Waters Barrier Island: Coral Reef Formed by cnidarians that secrete a hard, calciferous (calcium carbonate) shell skeleton –providing homes for a diversity of marine life species Not formed by depositing of sediment Vulnerable to physical stresses, change of light intensity, and water temperature

FW & SW Upwelling -Seasonal movement water from the cold, nutrient rich bottom to the surface -Provides nutrients to organisms living in the photic zone causing exponential growth

After upwellings, fisheries boom Organisms like single-celled algae grow exponentially –Algal blooms can lead to red tide –Deadly toxins released into water from dinoflagellate wastes –Result massive fish and marine life die off Red Tide Formation

Sumary Choose 1 of the following: 1.Explain how the atmosphere effects the hydrosphere. 2.Compare & contrast sea water salinity to fresh water salinity. 3.Create a story about the life of a river starring you as a drop of rain. 4.Explain vertical stratification in fresh water biomes.