The Hydrosphere

Name the three major processes in the water cycle. Describe the properties of ocean water. Describe the two types of ocean currents. Explain how the ocean regulates Earth’s temperature. Discuss the factors that confine life to the biosphere. Explain the difference between open and closed

systems.

Objectives

The hydrosphere includes all of the water on or near the Earth’s surface.

This includes ◦ water in the oceans◦ lakes◦ rivers◦ wetlands◦ polar ice caps◦ soil◦ rock layers beneath the Earth◦ clouds

The Hydrosphere

The water cycle: is the ◦ continuous movement of water

from the ocean to atmosphere to land back to ocean.

Evaporation: change of a substance from liquid to gas.

Water continually evaporates from the Earth’s oceans, lakes, streams, and soil, but the majority evaporates from the oceans.

The Water Cycle

Condensation is the change of state from a gas to a liquid.◦ Water vapor forms water droplets ◦ Droplets form clouds ◦ Clouds create heavier drops that fall as Precipitation

Precipitation is any form of water that falls to the Earth from the clouds including ◦ Rain◦ Snow◦ Sleet◦ Hail

The Water Cycle

The Water Cycle

All of the oceans are joined together called:◦ world ocean.

Oceans regulate the planet’s environment.

Earth’s Oceans

The largest ocean is the Pacific Ocean ◦ surface area of about

165,640,000 km2.◦ The deepest point is

Challenger Deep.

It is 11,033m (6.85miles) below sea level ◦ deeper than Mount

Everest is tall.

Earth’s Oceans

Largest Ocean: Pacific Ocean◦ divided into two parts

North Pacific and South Pacific ◦ based on the direction of the surface currents.

North Pacific: currents move clockwise

South Pacific: currents move counter-clockwise

Earth’s Oceans

Pacific Ocean Currents

2nd largest ocean: Atlantic Ocean◦ about 1/2 the size of Pacific Ocean ◦ Covers 81,630,000 km2.

Can be divided into a north and south based on the directions of surface currents.

Earth’s Oceans

3rd largest ocean: The Indian Ocean ◦ covers73,420,000 km2.

The smallest ocean: Artic ocean ◦ covers 14,350,000 km2.◦ much of its surface is covered by floating ice

Summer in the Arctic

Earth’s Oceans

What makes ocean and fresh water different?◦ SALT

Salinity is a measure of the amount of dissolved salts in water.◦ lower in places:

that get a lot of rain where fresh water flows in to the sea.

◦ higher where water evaporates rapidly leaving salts behind.

Ocean Water

Most of the salt in the ocean is sodium chloride (NaCl a.k.a. table salt)

although many other elements can be found in the ocean as well.

Ocean Water

Surface: warmed by the sun stirred up by waves and currents so the

◦ warm surface zone may be 350 m deep. Thermocline: Below the surface zone

◦ about 300 to 700 m ◦ temperature falls rapidly.

depths of the ocean ◦ no sunlight = very cold, just above freezing.

Temperature Zones

Temperature Zones

Ocean Layers

Epipelagic Zone

Mesopelagic Zone

Bathypelagic Zone

Abyssopelagic Zone

Hadalpelagic Zone

Benthic Zone

Ocean Layers (From Surface to Floor)

Epipelagic Zone: Surface – 650 ft

◦Upper ocean zone. Full of life

◦enough sunlight to sustain photosynthesis.

(a.k.a.) Euphotic Zone.

Ocean Zones

Mesopelagic Zone: 650 ft – 3300ft

◦ not enough sunlight to sustain photosynthesis.

(a.k.a.) Disphotic Zone.

Ocean Zones

Bathypelagic Zone: 3300 ft- 13000ft lowest level on the continental shelf. No sunlight.

Aphotic Zone: No Sunlight Plants cannot grow.

No primary productivity. All the food in this zone comes from

dead material sinking from the higher layers.

Ocean Zones

Abyssopelagic Zone: 13000ft- ~20000ft

◦ Largest layer of the ocean. ◦ It is completely dark, and the ◦ Low oxygen concentration

Extreme pressure. No sunlight.

Aphotic Zone: No Sunlight Plants cannot grow.

No primary productivity. Does Support life.

◦ Organisms feed off of dead and fecal materials that sink to the sea floor.

Ocean Zones

Hadalpelagic Zone: 20000ft and Lower

Deep ocean trenches such as the Mariana Trench and others.

Shares same characteristics as the Abyssal Zone except even deeper.

No sunlight. Aphotic Zone: No Sunlight Plants cannot grow.

Ocean Zones

Benthic Zone: This is the ocean floor.

◦ Mudlike sediments form bodies of dead organisms

◦ Fecal pellets of aquatic organisms also accumulate here.

Sediment of dead organisms and fecal matter can be a mile thick. Aphotic Zone: No Sunlight Extreme pressure

Ocean Zones

Light

Important functions:◦ Absorb and store energy from sunlight ◦ This regulates temperatures in Earth’s atmosphere.

Because the ocean both absorbs and releases heat slower than land, the temperature of the atmosphere changes more slowly.

If oceans did not regulate temperatures, temperatures would be too extreme for life to exist on Earth.

A Global Temperature Regulator

Local temperatures are regulated by the world ocean.

Currents circulate warm water causing land areas they flow past to have more moderate climates.

For example, the British Isles are warmed by the waters of the Gulf Stream.

A Global Temperature Regulator

surface currents: Streamlike movements of water that occur at or near the surface.◦ wind driven and result from global wind patterns.

Surface currents:◦ can be warm or cold ◦ They do not readily

mix with one another.

Ocean Currents

Ocean Currents

Deep currents ◦ movements of water that flow very slowly along

the ocean floor. Deep currents form when the cold, dense

water from the poles sinks below warmer, less dense ocean water and flows toward the equator.◦ The densest and coldest ocean water is located

off the coast of Antarctica producing a deep current called the Antarctic Bottom Water.

Ocean Currents

Fresh water:◦ Most fresh water is locked up in icecaps and glaciers◦ The rest is found in

lakes rivers wetlands soil and atmosphere

A river system: ◦ network of streams that drains an area of land◦ including the main river, smaller streams or rivers

that flow into larger ones.

Fresh Water and River Systems

Precipitation sinks into the ground and run off the land.

Most of this water trickles down through the ground and collects as groundwater.

Groundwater fulfills the need for fresh drinking water, and supplies agricultural and industrial need.

Makes up 1% of all the water on Earth,

Ground water

A rock layer that stores and allows the flow of groundwater is called an aquifer.

Aquifers

The biosphere is the part of Earth where life exists, ◦ 11 km into the ocean ◦ 9 km into the atmosphere.

The materials that organisms require must be continually recycled.

Biosphere: only area with Suitable conditions for life due to abundant sunlight.

The Biosphere

Plants need sunlight to produce food◦ almost every other organism gets its food from

plants and algae. Most of the algae float at the surface,

known as phytoplankton.

The Biosphere

When an organism dies, its body is broken down and the nutrients become available for use by other organisms.

This flow of energy allows life on Earth to continue to exist.

Energy Flow in the Biosphere

Closed systems are systems that cannot exchange matter or energy with its surroundings.

Open systems are systems that can exchange both matter and energy with its surroundings.

Earth is a closed system with respect to matter Earth is a open system for energy energy travel

◦ Sun ◦ Plant◦ animal

Energy Flow in the Biosphere