EAR 117 - oceanography unit 1

geological (paleo) oceanography

the study of earth at the sea’s edge and below its surface, and the history of the processes that form the ocean basins

physical oceanography

the study of physical properties of the ocean, waves, currents, and tides, and how they affect the marine environment

chemical oceanography

the study of the compositions and history of the water, its processes and its interaction

biological oceanography

marine organisms and the relationship between these organisms and the environment in the ocean

Scripps Institution of Oceanography and Woods Hole Oceanographic Institution

famous institutions that study oceanography

argo floats

a new apparatus that helps oceanographers measure temperature and salinity by transmitting data to a satellite to shore observatories

Half lives

the amount of time a sample of a substance is reduced to half of its initial amount/concentration

hydrologic cycle

the movement of water through reservoirs

transpiration

plants absorbing water through their roots and turning it into water vapor that gets released by the pores in their leaves

sublimation

the conversion of ice directly to water vapor

need to know freshwater sources

Ice caps and glaciers (biggest), freshwater lakes, rivers (smallest)

the five oceans

atlantic, pacific, indian, southern, artic

layers of the earth

Crust (what humans are standing on), Mantle (supports the weight of the earths crust), the core

isostasy

mechanism by which areas of earth’s crust rise of subside until their masses are in balance, “floating” on the mantle

continental drift theory

the theory that all 7 continents were originally connected together but eventually drifted apart

wegener evidence for continental drift

all of the continents fit together, fossil distribution over continents, ancient mountain belts that match together, matching rock units, glacier deposits among multiple continents

seafloor spreading theory

the theory that the seafloor is slowly pushing continents further and further away from each other because of heat from the core

paleomagnetism

study of ancient magnetism recorded in rocks; the study of changes in location of Earth’s magnetic poles (north and south poles) through time and reversals in Earth’s magnetic field; used to understand the spreading of the seafloor

3 types of plate boundaries (plate tectonics)

Divergent (move apart), convergent (move together), transform (slide past eachother)

different types of convergent boundaries

Ocean-ocean convergence (2 plates in the ocean moving towards each other), Ocean-continent (1 plate in the ocean and 1 plate on land) continent - continent ( 2 plates on continents)

Hawaiian Island Hotspot

in Hawaii, the closer the volcano is to the hotspot, the younger the island is. Once a new volcano erupts on the hotspot, the old volcano will move further away from the hotspot

mantle plumes

magma will be released from the earth’s core in a mushroom top shape (a plume), when it reaches the crust, the tectonic plates will move and form a volcano

how to measure depth

Precision Depth Recorder (PDR), Using sound to map the sea floor, or sea-surface elevation

identify generalized ocean basin cross-section

shelf, slope, trench, seamount, mid-oceanic ridge

neritic vs pelagic

neritic is closer to the shore line, Pelagic is further away from the shore line

how are sediments able to move in the ocean

only smaller sediments are able to travel further in the ocean because of their small size, it’s easier for the waves and currents to move the smaller sediments. we are more likely to see neritic sediments

Biogenous sediments

foraminifera, coccolithophores, diatom, radiolaris

characteristic of biogenous sediments

Foram and coccoliths are made up of Ca shells, Diatom and radiolaria are made up of Si shells, Foram and Radiolaria are considered “animals” while diatom and coccoliths are considers plants. The animals are bigger than plants

calcification vs dissolution

calcification/precipitation: the forming of Calcium Carbonate ( Ca + CO3 = CaCO3), dissolution/compensation: the destruction of calcium carbonate (CaCO3 = CO3 + Ca)

how marine sediments are studied

dredging the seafloor, piston corer, gravity corers, box corers

dredging the seafloor

a large metal basket that gets dragged along the seafloor to catch sediments, lots or arguments against this because it disrupts sea life and is wasteful in killing lots of sealife

Piston Corer

a big syringe that goes into the sea floor to collect a sample of the sea floor

Gravity Corer

a long PVC pip that goes into the ocean floor to collect a sample of the sea floor, has a heavy weight on top of the pip to push the pipe

box corer

drops a metal box into the sea floor and collects a sample of the seafloor in a box size sample

gas hydrates

ice-like crystallines solids where low-density gases (methane) are trapped inside cage-like water molecules; form in high pressure, low temp; studied for their energy potential, role in global climate dynamics, and their influence on seafloor stability