Oceanography

What is the evidence for large magnitude earthquakes in the Pacific NW? When was the last great earthquake and tsunami?

-Earthquakes occur wherever the lithosphere is deformed (strained) by plate-driving forces (either stretching "tension" or collisional). Main ingredients for earth quaked are cold, strong rocks that can accumulate strain up to a certain point -The last great earthquake and tsunami occurred on January 21, 1700 at 9pm.

The carbonate compensation depth (CCD) is

-The ocean depth below which calcium carbonate sediments are not preserved -is largely controlled by the rate at which carbonate dissolves in sea water -explains why calcareous oozes are limited to the shallower depths of the oceans such as the tops of ridges and rises

What are oxygen isotopes? What do they tell us about ancient climates?

...

What are the main planktonic groups of animals and plants that produce biogenous sediments?

...

What process is responsible for plate cooling and deepening?

...

19th century curiosity about the oceans and commercial shipping (across the Atlantic) and whaling (in all oceans) increased

...and voyages for scientific purposes were initiated

The ocean covers...

71% of the Earth's surface.

What are large igneous provinces?

Also referred to as "flood basalts". Rapid, voluminous emplacements of predominately mafic igneous rocks.

Why is climate change important?

Because climate change also changes the temperature of the ocean there fore the ecosystem as well

What are biogenic oozes made of?

CaCO3 and SiO2 skeletons of plankton

Hot spots apparently begin with

Catastrophic volcanic activity recorded as large igneous provinces

What is ice-rafted debris?

Chunks of ice that have fallen or melted off of glaciers, the debris is the fallout of sediment melting from the icebergs

James Cook

Constructed charts of coastlines especially for the South Pacific; secondary discovery the Hawaiian Islands

The broad platform that represents the submerged edges of a continent is the...

Continental Shelf

How are tsunamis generated?

Earth Quakes- subduction plates moving.

"Climate" and "weather" mean the same thing

False

What are hot spots?

Heated rock rises from thin collumns in the mantle or small cracks in the crust, often forming volcanoes and/or seamounts

"Black Smoker" are...

High-temperature hydrothermal vents at spreading ridges

The lava that erupts in the Hawaiian Islands is thought to be the result of a:

Hot Spot

Over 97% of the water on the Earth is...

In the ocean

What is mantle convection, and how does it influence plate tectonics?

It is the driving force of plate tectonics

What exactly is oceanography, AND how does it differ from other fields of science?

Oceanography is often sub-divided into several research disciplines (physical, chemical, geological & geophysical, biological, and ocean engineering). It is considered to be more interdisciplinary and collaborative than other sciences, and it requires sharing large expensive facilities (like ships, satellites, super-computers)

Define the Wilson Cycle:

Oceans come and go, but contents remain, they grow slowly with time a a result of plate collisions.

What are mantel plumes?

Part of the circulation in the mantel, driven by temperature and differences.

What does the location of earthquakes tell us about plate tectonics?

Plates are moving

Biological Oceanography

Prochlorococcus - the most important microbe you've never heard of (oxygen producer); perhaps the most abundant organism on Earth

Edward Forbes: British naturalist (1815-1854)

Proposed the hypothesis that no life (azoic) existed in the oceans below 550 m

Benjamin Franklin is recognized in Oceanography for...

Publishing the first chart of the Gulf Stream

Briefly explain how SONAR works

SONAR is an acronym for sound navigation and ranging. It is based on the simple relationship of sound (acoustic) velocity = distance/time. A SONAR instrument on the bottom of a ship or from an underwater vehicle sends pulses of sound to the seafloor and determines the amount of time it takes for them to return to the instrument. Knowing this along with the average velocity of sound in seawater yields a distance or depth. That distance or depth is used to produce a map of the ocean floor showing its topographic features.

The distribution of earthquakes and volcanoes on Earth correlates best with

Tectonic Plate Boundaries

Carbonate sediments are rare in the deepest parts of the ocean because...

The carbonate shells dissolve in deep water (below the carbonate compensation depth)

Why are subduction-related volcanoes the most dangerous on Earth?

The create large hot spots and plums

How does the depth of the ocean floor change with age?

The depth becomes of the ocean floor becomes shallower with age.

Mantel Convection

The driving force for plate tectonics

How does the distribution of volcanoes relate to plate boundaries?

There are hot spots under they volcanoes

There is a record in deep-sea sediments of long-term changes in the orbital motions of the Earth around the Sun, because the orbit affects the climate of the Earth.

True

"Turbidities" are

Underwater avalanches of loose sediment usually triggered by earthquakes that flow down submarine canyons

Atoll

When a volcano become inactive and skins and coral grows on it. The volcano part of the island then disappears underwater.

The average depth of the ocean is...

about 3,800 meters.

Biological Oceanography (Marine Biology)

concerned with the organisms that live in the oceans, and their relationships to the environment;

The oldest sediments in the ocean

date back to about 200 million years, the age of the oldest ocean floor

The following was recognized early in the century as evidence for continental drift:

diversity of species (fossil evidence)

Which materials listed below, found in deep- sea sediments, are composed of calcium carbonate (CaCO3)?

foraminifers

Physical Oceanography

investigates how and why ocean currents flow, and air-sea interactions such as the generation of waves by the wind;

Oceanography

is a broad science that has the understanding of the oceans as its common goal.

What is Paleoceanography?

is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation and biological productivity

The oozes on the seafloor in the deep ocean consist mostly of:

microscopic shells of single celled plants and animals that live near the surface of the ocean

A plate capped by oceanic crust subducts beneath a plate capped by continental crust because:

oceanic crust is thinner than continental crust.

The science of oceanography is customarily divided into four categories, which are...

physical, geological, chemical, and biological

Piloting/Dead Reckoning

required the early navigators to plot their courses according to the stars and landmarks.

How are sediments classified?

size, composition

The term bathymetry refers to

submarine topography

What are the principal types of marine sediments?

terrigenous, biogenous, hydrogenous, cosmogenous

Ocean Engineering

the branch of engineering that designs equipment and installations to be used in the oceans.

The Mariana Trench is 11,022 meters deep and...

the deepest spot in the ocean.

Geological Oceanography (Marine Geology)

the study of rocks and sediments found within the oceans, and of the processes responsible for their formation;

Chemical Oceanography

the study of the composition of sea water and the processes that control and alter this composition, including marine pollution;

Marine Geophysics

the study of the rock structure within the ocean basins, the properties of rocks such as their magnetism, and the occurrence and cause of earthquakes;

According to the plate tectonic theory, most new crust is formed as the result of:

volcanism at mid-ocean ridges.

According to plate tectonic theory, the Mid- Atlantic Ridge should be

younger than east coast of the United States.

Matthew Fontaine Maury: U.S. naval officer

• Compiled information on winds and currents; • Published "The Physical Geography of the Sea" (1855); • Called the "father of physical oceanography"

Charles Darwin: British naturalist

• Voyage of the Beagle (1831-1836), studied geology and biology of the South American coastline; • Developed theory of organic evolution based on natural selection; published "On the Origin of the Species" (1859)