Oceanography exam 1, chp 1 2 4

Why does the sea floor have a striped pattern of magnetic anomalies that is symmetric with respect to the mid-ocean ridge? (3)

- The igneous rock of the ocean floor preserves Earth's existing magnetic field as the rock cools. - The polarity of Earth's magnetic field experiences reversals - The ocean floor is spreading apart and new sea floor is forming

Of the following statements about Earth's magnetic field, which is/are true? (4)

- The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic south pole. - The lines of the magnetic force are parallel with Earth's surface at the equator - The lines of the magnetic force are perpendicular relative to Earth's surface at the magnetic north pole - The magnetic north pole may reverse so that it is located near the geographic south pole

Which of the following ideas support our current scientific understanding of the development of life on Earth?

-The "prebiotic soup" of the primitive oceans provided favorable conditions for life to develop. -As life evolved it significantly changed Earth's environment. -Primitive life likely existed without the need for oxygen. -Early organisms evolved into more-complex organisms over geologic time.

Of the following statements about the asthenosphere, which is/are true?

-The asthenosphere is very hot and contains areas of partially molten rock. - The asthenosphere is a highly viscous layer located beneath the lithosphere

Of the following statements about density stratification, which is/are true? Choose all that apply

-The origin of Earth's oceans and atmosphere are a result of density stratification. -Density stratification has caused the highest-density material to be found at Earth's core. -Density stratification has caused Earth's internal structure to be layered. -Outgassing is a direct result of density stratification.

Which of the following lines of evidence did Alfred Wegener use to support the concept of drifting continents? (4)

-the pattern of similar mountain belts on different continents -evidence of glaciers in areas that are now tropical -the way the shapes of the continents fit together like pieces of a jigsaw puzzle - the distribution of species of fossils

The average depth of the world's oceans is approximately

3,682 meters (12080 feet)

Archeological evidence suggests that boat technology was developed about ________ years ago.

40,000

On average, how long do periods of reverse and normal polarity last?

500,000

Radioactive materials can sometimes be used to determine the:

Age of rocks

Which of the following is an example of an oceanic-oceanic convergent plate boundary?

Aleutian islands

What do all plate boundaries have in common?

All associated with zone of earthquakes

The nebular hypothesis suggests that

All bodies in the solar system formed from an enormous gas cloud

Which of the following is an example of an oceanic-continental convergent plate boundary?

Andes Mountains

Which of the following mountain ranges are examples of continental arcs?

Andes and Cascades

Isostatic adjustments are the result of the buoyancy of Earth's lithosphere as it floats on the ________ below which is denser and plastic like.

Asthenosphere

The four principal ocean basins (plus an additional ocean) on Earth are the:

Atlantic, Pacific, Indian, Southern, and Arctic Oceans.

Earth's early atmosphere most likely included:

Co2, water vapor, ammonia, methane

The separation of the Earth into layers while it was molten was the result of the

Differing denities off the elements that make up the earth

What is a nebula?

Diffused dust and gas

The Mid-Atlantic Ridge is an example of a:

Divergent plate boundary.

How did the moon form?

Due to the impact of a mars-sized body with the earth

How are Earth's geographic and magnetic axes oriented relative to each other?

Earth's geographic and magnetic axes are oriented at a slight angle to each other.

Which of the following statements about earthquakes with magnitude greater than 4.0 is most accurate?

Earthquakes with magnitude greater than 4.0 occur in a pattern than correlates loosely with plate boundaries.

Which of the following parts of Polynesia was populated last?

Easter island

The first person we are aware of who determined the circumference of the Earth using trigonometry and the angle of sunlight at Alexandria, Egypt, was:

Eratosthenes

Who is credited with being the first person to accurately determine Earth's circumference?

Eratosthenes

Who was killed in the Philippines during his last sea voyage after a skirmish with local people?

Ferdinand Magellan

Which of the following is an example of a continental-continental convergent plate boundary

Himalaya mountains

Which of the following statements is true regarding tectonic plates?

Include oceanic and continental crust

Which of the following statements is most accurate?

India collided w asia 30 million years ago

The explorer who advanced oceanography by introducing systematic soundings, or depth measurements, was

James Cook

Who left Spain in September 1519 and became the first person to complete a circumnavigation of the globe when he returned to Spain three years later?

Juan Sebastian del Caño

Which of the following is Earth's rigid layer that includes the crust plus the topmost portion of the mantle?

Lithosphere

Earth's magnetic field is similar to what?

Magnetic field of a bar magnet

Which geologic features are associated with convergent boundaries?

Ocean trenches and volcanoes

which is true about sea floor magnetic anomalies

Oriented parallel to the mid ocean ridge

Which of the following is earths liquid iron-nickel layer?

Outer core

Which of the following tectonic plates are oceanic?

Pacific plate, Nazca plate

The first recorded circumnavigation of Africa was made by

Phoenicians

Which of the following is an example of a continental-continental divergent plate boundary?

Red sea

Which of the following is an example of a continental transform plate boundary?

San andreas fault

Why didn't india subduct under asia

Similar densities

Deep ocean trenches are associated with:

Subduction zones

What would happen to Earth if ocean floor were created at divergent boundaries at a faster rate than it is destroyed at convergent boundaries?

The Earth would increase in volume.

Which of the following statements is true of the lithosphere?

The lithosphere is composed of the crust and the uppermost portion of the mantle.

which one is true about the age of the ocean crust

The oldest ocean crust is about 200 million years old and is located near an ocean trench

Compared to continental crust, oceanic crust is generally __________

Thinner, denser, darker in color, and at lower elevations

Where would the north end of a magnet point during a time of reverse polarity?

Towards the magnetic south pole

According to the Geologic Time Scale, which selection lists the correct order of coexistence, from earliest to latest?

Trilobites and amphibians, insects and dinosaurs, dinosaurs and birds, flowering plants and fishes, humans and reptiles

Who is credited with being the first European to see the Pacific Ocean?

Vasco Nunez de Balboa

What are the reaction products of respiration?

Water co2

To find the largest area of the ocean with the oldest ocean crust, you should go to the ________.

Western pacific

Did any subduction occur during the collision of India and Asia?

Yes; ocean basin between these two continents subducted under Asia.

The important contribution to navigation made by Eratosthenes in the third century BC was __________.

a reasonably accurate calculation of the circumference of our planet

What is a volcanic arc?

a row of volcanoes that forms on the overriding plate near a subduction zone

Evidence shows that periodic reversals of Earth's magnetic field have resulted in __________.

a symmetrical pattern of normal and reverse magnetization in ocean crustal rocks

What is a scientific theory

a well-substantiated explanation that is supported by facts, tested hypotheses, and logical inferences

Where is the youngest ocean floor found?

along the crest of mid-ocean ridges

Which of the following is characteristic of oceanic-continental convergent plate boundaries?

andesitic volcanoes

Based on definition, it is more appropriate to consider which ocean as a sea?

arctic

Which ocean is the shallowest ocean in the world?

arctic

Oceanic crust is primarily

basalt

According to the fossil record on Earth, the earliest-known life-forms lived in sea floor rocks about 3.5 ________ years ago.

billion

Earth's atmosphere became oxygen rich about 2.45 ________ years ago

billion

Trilobites were dominant during which geologic period?

cambrian

One of the reasons that free oxygen in our atmosphere is important to the development and maintenance of life on Earth is because oxygen:

can form ozone and block some UV radiation

Although Earth's oceans have existed since early in the formation of the planet, its ________ must have changed.

chemical compostion

Which type of plate boundary exists between India and Asia today?

convergent

Where are tectonic plates located?

earths surface

Tectonic plates move about as fast as ________.

fingernails grow

The study of the structure of the sea floor and how the sea floor has changed through time is an example of ________ oceanography.

geological

A commentary model of the formation of Earth's ocean must include the chemical difference between the ________ in comet ice and that in Earth's water.

hydrogen

A tentative, testable statement about the general nature of a phenomenon is called a/an:

hypothesis

Climate distribution on Earth is primarily controlled by:

latitude

Tectonic plates are pieces of the ________ that float on the more fluid ________ below.

lithosphere; asthenosphere

What is the basis for relative positions of Earth's physical layers?

material density, with the least-dense material on the surface and the most-dense material in the center

Which geologic features are associated with divergent boundaries?

mid-ocean ridges and continental rift valleys

Which of the following is the first step of the scientific method?

observation

What are the reaction products of photosynthesis?

oxygen gas and sugar

Which ocean covers more than half of the ocean surface area on Earth?

pacific

Which ocean is the deepest ocean in the world?

pacific

In general, how do magnetic objects align relative to Earth's magnetic field?

parallel

The seafloor magnetic pattern is best described as:

parallel to and symmetric about mid-ocean ridges.

The study of the transmission of light and sound in the oceans is an example of ________ oceanography.

physical

Earth's current atmosphere supports animal life because __________.

plant photosynthesis provides oxygen that is critical for aerobic respiration

Fossils of ancient tropical plants are currently found near the poles because the:

plants lived in the tropics, but landmasses have drifted to current locations.

Where do most earthquakes occur?

plate boundaries

The method of determining latitude in the Northern Hemisphere by measuring the angle between an observer's line of site to the North Star and line of site to the northern horizon was developed by:

pytheas

Our world ocean can be divided into four principal oceans plus an additional ocean, based on the ________ of the ocean basins and the ________ of the continents.

shape, postion

Where do magnetic field lines exit the Earth today?

south pole

What is meant by the term plate boundary?

the edge of a plate, where two plates meet each other

Sea floor spreading along the axis of an oceanic ridge results in symmetrical patterns of all of the following EXCEPT ______________.

the location of subduction zones

Plate tectonics and evolution, which are held with a high degree of confidence because of rigorous testing and verification, are examples of

theories

Where did the energy of the Sun come from originally?

thermal energy that was converted from the gravitational energy of the original nebula collapse

Which plate boundary is NOT associated with volcanic eruptions?

transform

Which of the following is characteristic of continental-continental convergent plate boundaries?

uplifted mountain ranges

Which of the following is characteristic of oceanic-oceanic convergent plate boundaries?

volcanic island arcs

Current scientific knowledge indicates that the most likely origin of most of Earth's oceans was due to ________.

water vapor released from volcanic outgassing