astronomy chapter 9

What do we conclude if a planet has few impact craters of any size?

Other geological processes have wiped out craters.

The photo shows a fragment of the planet's surface. There is a peak with tall cliffs around the rim. Volcanic crater can be seen in the middle of this peak. The diameter of this crater is about 50 kilometers. The arrow in this photo is pointing at a feature known as _____________________.

Olympus Mons

Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars?

Olympus Mons

In the context of plate tectonics, what is a subduction zone?

a place where a seafloor plate is sliding under a continental plate

Old Faithful Geyser at Yellowstone National Park in the United States acquires its energy from a

hot spot

Go to the screen in the interactive figure called "Key Evidence of Water," then zoom in on the "Southern Highlands." Which geologic processes are most clearly evident in the southern highlands?

impact cratering and erosion

The processes responsible for virtually all surface geology are _________.

impact cratering, volcanisms, tectonics, and erosion

Valles Marineris is a

large canyon on mars

Which of the following show evidence of ancient river beds?

mars

What kind of surface features may result from tectonics?

mountains volcanos valleys cliffs

impact cratering

old surface features of the lunar highlands

How many of the five terrestrial worlds have surfaces being constantly reshaped by plate tectonics?

one

Olympus Mons is a

shield volcano on Mars.

Shallow-sloped shield volcanoes are made from lava that

has a medium viscosity.

A planet is most likely to have tectonic activity if it has

high internal temperature

The photograph shows the Moon with its surface details clearly visible. The first arrow points to the large uniformly dark area on the Moon's surface. The second arrow points to the huge dark ring with white center located in the bright area of the Moon, at the bottom of the visible side. The third arrow points to the large uniformly bright area on the Moon's surface. The fourth arrow points to the bright bottom edge of the visible side of the Moon. Which feature in this photo of the full moon is one of the lunar maria?

1

The figure shows a spherical layer below the Pacific Ocean, North America, Atlantic Ocean and Europe. The bottom of the layer corresponds to the upper mantle. Convection cells are located in the middle of the layer. They are indicated by the cycled arrows. Label three is placed inside one of the convection cells below North America. There are also brown arrows, which show the movement of the plates. One of them points from the bottom of the Pacific Ocean to the right and inside the upper mantle layer. Label one is placed here. The red arrow points vertically upward, to the Central America region, somewhere between two plates. The brown arrow points to the same region horizontally, from right to left. Another red arrow points vertically upward through the layer to the middle of the Atlantic Ocean. Label two is placed here. Label four is placed at the eastern edge of North America. This diagram represents the conveyor-like action of plate tectonics on Earth. Which numbered position represents a place where new seafloor crust is being made?

2

Volcanism

Big Island of Hawaii smooth surfaces of the lunar maria Mars's Olympus Mons

erosion

Earth's Grand Canyon

How did the lunar maria form?

Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins.

The photo shows a fragment of the planet's surface. It has a beige color, and there are a few craters, cliffs, and patterns, which look like branches, on the surface. This photo was taken from orbit around some planet. What planet is it, and how do you know?

Mars because we see dried up riverbeds

Assuming that features you see on Mars are similar to features found on Earth, what would a casual inspection of the interactive photo of Mars lead you to suspect about water on Mars?

Surface water only exists as frozen ice.

Go to the screen in the interactive figure called "Major Geological Features." Which of the following statements about the Tharsis Bulge, often simply called "Tharsis," are true?

Tharsis has several large volcanoes. One end of Valles Marineris is connected to Tharsis. Tharsis has higher elevation than surrounding regions

The diagram shows the amount of volcanic/tectonic activity for the Earth, Venus, Mars, Mercury and the Moon. All of them have come through the period of heavy cratering in the first billion years of their history. Since then all of them experienced low levels of cratering. For the Earth amount of volcanic/tectonic activity remains the same through all 5 billion years of its history. Almost the same situation is for Venus, though the current level of activity is unknown. For Mars, the amount of activity has been permanently reducing, and for approximately the last billion years it is unknown. Both for Mercury and for the Moon, the level of activity decreased to the zero value after the first billion years of their history. Planets are shown on the diagram, they are placed in the order corresponding to their size. This figure summarizes the geological histories of the terrestrial worlds. Based on this figure, what can you conclude?

The most important factor in a planet's geological history is its size.

These four photos show features of Earth that change with time, some fast and some slow. Which one of these features is being shaped primarily by the process we call tectonics?

The photo shows a space view of the peninsula surrounded by the ocean. There is a mountain chain with peaks covered with snow on the peninsula.

The photo shows a fragment of Venus' surface. Two volcano craters are located in the middle of the photo. The area where the craters and their hills are located is light yellow, and the radius of this area is about 250 kilometers. The area around is darker. This image shows two tall volcanoes on Venus. Why is it yellow?

The yellow color is arbitrary because this image was created with radar data rather than visible light.

The figure shows the relief map of Earth. There are several yellow lines on this map. One of them goes along the western edge of North America, from North to the South. Then it divides into two lines, one follows the western edge of South America while the other goes to the Pacific Ocean. This line divides again, the western branch goes to the south of west, the eastern branch returns to the South American shore. Then the line goes to the east, mostly along Antarctica. Another yellow line goes through the middle of the Atlantic Ocean to the north. Next yellow line goes between Africa and Europe, then it turns to the south and intersects with the horizontal yellow line approximately in the middle of the Indian Ocean. One more yellow line goes along the eastern edge of Eurasia, then follows the southern direction along Philippines and eastern part of Australia. What is the significance of the yellow lines on this map of Earth?

They represent boundaries between the plates that make up Earth's lithosphere.

The photo shows a hill covered with rocks of different sizes. Even layers can be clearly seen on the foreground rocks. This photo from the Curiosity rover shows what appears to be layered sedimentary rock on Mars. What does this photo seem to be telling us?

This region of Mars once held a body of water such as a lake.

What are the basic requirements for a terrestrial world to have a global magnetic field?

a core layer of molten, convecting material and sufficiently rapid rotation

Based on its surface features, the most important event on Venus in the past billion years or so was _______.

a global "repaving" that erased essentially all the surface features that had existed earlier

The three principal sources of internal heat of terrestrial planets are

accretion, differentiation, and radioactivity.

The figure shows a cavity in the shape of the bottom part of the sphere located in the flatlands. The radius of the cavity is approximately 600 meters. The geological feature in this photo is _________.

an impact crater

How have we been able to construct detailed maps of surface features on Venus?

by using radar from spacecraft that were sent to orbit Venus

tectonic

current locations of Earth's continents Mars's Valles Marineris Mercury's many long, tall cliffs

The core, mantle, and crust of a planet are defined by differences in their

composition

Australia is composed of relatively old and thick

continental crust

Earth is the only terrestrial planet to have experienced tectonic stresses and volcanic activity.

false

The earthquakes that occur in Southern California generally occur above a

fault

What process has shaped Earth's surface more than any other?

plate tectonics

Which internal energy source is the most important in continuing to heat the terrestrial planets today

radioactivity

Which of the following best describes the lunar maria?

relatively smooth, flat plains on the Moon

____ found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock.

seafloor crust

The slowly increasing distance between South America and Africa is due to

seafloor spreading

layered _______ exposed by erosion can be seen when looking at the Grand Canyon in the United States.

sedimentary rock

The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that

the Caloris Basin formed toward the end of the solar system's period of heavy bombardment.

Which of the following describes tectonics?

the disruption of a planet's surface by internal stresses

Which of the following describes volcanism?

the eruption of molten rock from a planet's interior to its surface

Which of the following describes impact cratering?

the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface

What is differentiation in planetary geology?

the process by which gravity separates materials according to density

The lithosphere of a planet is the layer that consists of

the rigid rocky material of the crust and uppermost portion of the mantle.

Which of the following describes erosion?

the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary

Which two geological processes appear to have been most important in shaping the present surface of Venus?

volcanoes and tectonics