Oceanography Study of the water life and features

Oceanography Study of the water, life, and features of the ocean

Ocean Water �The water in the ocean is SALT WATER. �Salinity measures how “salty” the water is. �Salinity is the total amount of solid material dissolved in water. �The most common salt in the ocean is sodium chloride, common table salt. �Salt comes from chemical weathering of rocks and the Earth’s interior.

Ocean Water - Salinity

Ocean Water - Salinity �Salinity can change. �Things that cause the salinity to increase �Evaporation �Sea ice forming �Erosion

Ocean Water - Salinity �Things that cause the salinity to decrease �Precipitation �Sea ice melting �Icebergs melting �Runoff from land

Ocean Water - Salinity

Ocean Water - Temperature �Temperature of ocean water varies as a result of the amount of solar radiation. �Temperature of ocean water also varies with depth. �The thermocline is the layer of ocean water where the temperature drops rapidly.

Ocean Water - Temperature

Ocean Water - Layers �Temperature differences result in THREE layers of the ocean �Surface Zone �Shallow (300 to 450 meters) �Zone of mixing �Sun-warmed zone �Transition Zone �Between surface layer and deep zone �Thermocline and pycnocline

Ocean Water - Layers �Deep Zone �Sunlight never reaches this zone. �Temperatures are just a few degrees above freezing. �Constant high-density water

Ocean Water - Layers

Ocean Water - Density �Density is the mass per unit volume. �D = m / V �How heavy is it for its size? �Ocean water density is affected by two things: �Salinity �Temperature

Ocean Water - Density �The pycnocline is a layer where there is a rapid change in water density with depth. �Occurs at about the same place as thermocline.

Ocean Water - Density

Ocean Currents �Ocean current is the mass of ocean water that flows from one place to another. �Surface currents are movements of water that flow horizontally in the upper part of the ocean’s surface. �Surface currents are the result of winds.

Ocean Surface Currents

Ocean Currents �Gyres are huge circular moving current systems. �The rotation of the Earth can change the course of a current. �This is called the Coriolis effect. �Currents from low latitudes (near the equator) move heat to high latitudes (near the poles).

Ocean Currents - Gyres

Ocean Currents �Upwelling is the rise of cold water from deeper layers to replace warmer surface water. �Upwellings bring greater concentrations of nutrients to the ocean surface. �Density currents are vertical currents of ocean water that result from density differences among water masses. �Water density is affected by temperature and salinity.

Ocean Currents – Global Circulation

Ocean Currents - Waves �Waves get their energy from the wind. �Wave height is the vertical distance between the crest and trough. �Wavelength is the horizontal distance between two crests. �As waves reach the shore, the land slows them down. �This results in a decrease in wavelength and an increase in wave height. �This causes the wave to break.

Ocean Currents - Waves

Ocean Currents - Waves

Ocean Currents - Tides �Tides result from the gravitational pull of the moon and sun. �Spring tides are the biggest tides due to the Earthmoon-sun alignment. �These tides occur during the new and full moon phases of the moon. �Neap tides are the smallest tides due to the Earthmoon-sun alignment. �These tides occur during the first and third quarter phases of the moon.

Ocean Life �Organisms are classified based on where they live and how they move. �Plankton include all organisms that drift with the ocean currents �Phytoplankton are algal plankton (algae) and are the most important community of primary producers in the ocean. �Zooplankton are animal plankton. �Nekton are organisms that are capable of moving independently. �Benthos are organisms that live on or in the ocean bottom.

Ocean Life �Life Zones are determined by the availability of sunlight, the distance from the shoreline and the water depth. �Photic zone is the upper part of the ocean where there is sunlight for photosynthesis �Intertidal Zone is the strip of land where the land ocean meet. (between high and low tides) �Neritic Zone is the area from the low tide line out to the edge of the continental shelf.

Ocean Life �Oceanic Zone is the area beyond the continental shelf �Pelagic Zone is the open zone of any depth. �Benthic Zone is the sea bottom. �Abyssal Zone is a part of the benthic zone that has high pressure, low temperature, low oxygen, few nutrients, and no sunlight.

Ocean Edge �Shoreline � A Beach is build-up of sediment along the shore of a lake or ocean. �Waves erode the shoreline and are constantly changing the features of the beach. �Forces �Wave impact �Abrasion

Shoreline Features �Cliffs �Sea arches �Sea stacks �Spits �Bars �Tombolo �Barrier islands