Questions and Answers for Geology

Geology

What human activities can increase the rate of weathering?

Humans can affect weathering (breaking down of rock/soil) in several ways. Humans cause increases in acid rain and pollution, which increase the amount of weathering agents in the air and water,...

Latest answer posted November 14, 2008 8:41 am UTC

1 educator answer

Geology

What percent of the earth is land and how much is water?

There are generally two versions of the answer to this question. The first is the more general about 70% of Earth is water while about 30% is land (US Geological Society). The second is the more...

Latest answer posted January 25, 2014 12:39 am UTC

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Geology

What is Sima and Sial ? 

Sial refers to the earth’s crusts upper layer, it is made up of rocks abundant in silicate and aluminium based minerals. The word Sial itself is an amalgam of the first two letters of aluminium and...

Latest answer posted September 30, 2013 11:46 pm UTC

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Geology

What is an example of a continental divergent boundary? Give an example of divergent boundary.

The 3 types of tectonic plate boundaries are convergent, transform, and divergent. A convergent boundary is one where two plates are moving toward each other. Typically one plate is forced...

Latest answer posted November 18, 2008 10:23 am UTC

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Geology

What are the differences between a crater and a caldera? It seems that caldera is a larger depression than a crater....

In strictly volcanic terms, they are two different kinds of depressions. A caldera is formed when a large eruption of magma, or lava, leaves a gigantic empty chamber underground. The volcanic...

Latest answer posted December 30, 2010 5:42 am UTC

1 educator answer

Geology

Why is it important to study rocks? Why is it important to study rocks?

From a scientific point of view, rocks are essential trace fossils. A trace fossil is a type of imprint that reflects an animal's behavior. Some of this behavior is imprinted on fossilized rocks....

Latest answer posted December 11, 2009 3:54 am UTC

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Geology

Describe the earth's present condition.   Describe the present condition of the 'mother earth.'

The Earth has been around for about 5 billion years, and has about another 5 billion years to go. It has been cooling since its formation, and its surface temperature has stabilized within about...

Latest answer posted November 23, 2009 1:15 am UTC

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Geology

  Calculate the rate of the Pacific Plate's motion in cm per year for the island sequence Kauai to Oahu. Can you...

I assume that the data in your assumes it would take 2.1 x 10^6 years for the Pacific Plate to move the 181 km distance from Kauai to Oahu. If so, then: 1 km = 100,000 cm = 10^5 cm 181 km =...

Latest answer posted April 29, 2009 11:58 pm UTC

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Geology

Where is gravel found and how is it used by the building industry?

Gravel is formed of rocks that are unconnected to each other. While common perception of gravel is smaller rocks anywhere between one and three inches around, official designation of gravel...

Latest answer posted September 9, 2012 6:38 pm UTC

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Geology

Why is the interior of the earth very hot? describe the earth's interior why it is hot

There are several reasons why the earth's interior is so much hotter than its surface. First, the earth was formed through gravitational compression of many particles; a portion of that original...

Latest answer posted October 15, 2008 8:21 am UTC

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Geology

How do plants cause weathering?

Plants can cause both mechanical and chemical weathering. Mechanical weathering occurs when roots grow and cause the rock to break (just like the roots that crack the sidewalk). Chemical...

Latest answer posted October 28, 2008 10:08 am UTC

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Geology

What is the main type of energy used to help convert metamorphic rocks into ingneous rocks in the rock cycle ?

The main type of energy that is used to convert metamorphic rocks into igneous rocks is heat. Metamorphic rock can only be converted into igneous rock by being melted and, thereby, made into magma....

Latest answer posted February 2, 2010 2:01 am UTC

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Geology

How many degrees separate Tropic of Cancer from Tropic of Capricorn?

The Tropic of Cancer and Capricorn are imaginary lines of latitude running parallel with the Equator. Both are 23.5 degrees north and south of it, Cancer in the north, Capricorn in the south, so...

Latest answer posted November 23, 2009 10:13 pm UTC

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Geology

What percentage of land on earth is desert? I don't just want to know the largest desert but exactly how much of the...

Almost one-third of Earth’s surface is desert -- that is, area that gets less than 10 inches of rain each year. These areas have what’s called a moisture deficit: they lose more moisture through...

Latest answer posted January 10, 2009 7:55 am UTC

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Geology

Assume that parcel of air at the surface has a temperature of 29 degree C and a relative humidity of 50%. If the...

Clouds start forming when the temperature equals the dew point. Given the air temperature and relative humidity, the dew point can be calculated as: Td = T - ((100-RH)/5) = 29 - ((100-50)/5) = 29 -...

Latest answer posted March 29, 2015 2:05 am UTC

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Geology

What are depositional environments, and why can changes be seen vertically in a sequence of sedimentary rocks?

Depositional environments are the geological environments where particular types of sediments are deposited. Geological processes will later work on these sediments to convert them into rocks (a...

Latest answer posted July 3, 2013 1:35 am UTC

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Geology

Has there been more than one Pangaea? Since Pangea began to separate only 200 million years ago, and the Earth is...

We hypothesize, based on geology, that there were prior supercontinents. The Earth's crust is constantly in motion, rearranging and reshaping itself. Based on our current understanding of the age...

Latest answer posted January 15, 2014 5:23 pm UTC

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Geology

How far down does granite go into the earth?

We see granite everywhere. We see it as counter tops in many kitchens and we see it as flooring in many homes. Granite can be used indoors or outdoors because it is so resistant to cracking,...

Latest answer posted December 12, 2009 12:01 am UTC

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Geology

How did earth get its color?

The Earth has its color because 70% of the earth’s surface is covered by water. Our oceans and other bodies of water appear blue because of the way our sunlight is scattered as it goes through our...

Latest answer posted December 11, 2008 8:43 am UTC

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Geology

What is the geological significance of the "Ring of Fire?"

A particularly fascinating region of the Earth, the Ring of Fire is a series of volcanoes and extremely active seismic activity resulting from the plate tectonics prevalent around the perimeter of...

Latest answer posted September 25, 2013 2:29 pm UTC

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Geology

In which part of a river is a waterfall usually found ? I remember it was something like near a tributary or...

Waterfalls can happen in any part of a river's system where massive erosion or an abrupt steepening of the river's channel exists. Waterfalls are very erosive. The power with which the water pours...

Latest answer posted June 16, 2012 5:46 pm UTC

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Geology

what is the range of temperatures that exists within the asthenosphere? 

On the Earth Science Reference Table if you look at Inferred Properties of Earth's Interior on page 10, you will see that the temperature of the Asthenosphere or Plastic Mantle as it is also known...

Latest answer posted January 7, 2012 10:57 am UTC

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Geology

Why is the interior of the earth very hot?

The temperature of the earth's core is so high mainly because "it contains radioactive materials which release heat as they break down into more stable substances."...

Latest answer posted November 9, 2008 3:17 am UTC

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Geology

How the shape of the grain in the rock affect porosity. when the angularity of the grain increase the porosity increase

In Earth science, porosity refers to the empty spaces in a rock. If the grains in a rock are well sorted meaning they are almost all the same size, it will have higher porosity than a rock with...

Latest answer posted February 2, 2012 7:39 am UTC

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Geology

Most geologic events happened very slowly. Name two geologic events- one land building and one erosional- that happen...

Volcanoes may serve as land building events. The Hawaiian islands were formed as lava from volcanoes from deep under the ocean's surface erupted and the magma cooled and increased the height of the...

Latest answer posted October 3, 2012 9:44 pm UTC

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Geology

Did the breakup of Pangaea during the Jurassic Period led to the extinction of some dinosaurs and the evolution of...

Not only dinosaurs, but all living things either evolved or extinguished. Periodically, the Earth goes through a time of a "Great Die-Off," where the environment is so quickly and radically...

Latest answer posted November 17, 2009 1:15 am UTC

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Geology

Is the dome of the rock a meterorite? I heard the rock is from outer space I saw it and it looked diffrent from other...

No, the stone around which Jerusalem's iconic Dome of the Rock was built is not a meteorite. The stone, which has been given so much significance by Muslims and Jews, is part of a simple bedrock...

Latest answer posted December 28, 2009 10:05 am UTC

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Geology

How much of the Earth is land, and how much water?

29.22% of the earth's surface is land. 70.78% of the earth's surface is liquid water. Most of the earth's water is salty or permanently frozen. Approximately 3% of the 70.78% of earth's surface is...

Latest answer posted June 4, 2009 4:59 am UTC

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Geology

Name a place where two plates are sliding past each other. this is extrely important and would needed to be answerd...

One of the most important places in the United States where two plates are sliding past each other is in California along the San Andreas Fault. This fault line slices California in two. It begins...

Latest answer posted May 27, 2009 11:44 pm UTC

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Geology

Why is the interior of the earth very hot?

As we dig deeper into the earth, we notice that temperatures rise approximately by 30 ºC for every kilometer that we descend. Temperatures in the Upper Mantle of the earth can reach up to 1,400 ºC....

Latest answer posted August 17, 2019 6:48 am UTC

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Geology

How do you define compaction, cementation, and evaporation that forms sedimentary rocks?

Sedimentary rocks are a type of secondary rock because they are made of materials that have already been used as a part of rocks, plants, or animals. These usually accumulate as they are washed...

Latest answer posted June 7, 2008 5:29 am UTC

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Geology

Consider the following statements made by two students debating why the oceanic and continental plates move: Student...

The current version of the Earth's crust dates back about 225 million years, to the time of Pangea ("all earth.") That super continent has since broken up, and the fragments moved around the...

Latest answer posted May 16, 2011 7:21 am UTC

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Geology

What are fault lines?

To tell you about fault lines, I have to tell you about the planet earth. The planet earth has a crust. As with bread, the crust resides on the outside of the earth. It’s the planet’s outermost...

Latest answer posted August 8, 2020 2:53 pm UTC

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Geology

How are coral reefs formed?

It occurred to me that you might not know what coral is -- the substance that makes up the coral reef. Coral is the term for a colony of polyps, very small organisms that consist mainly of a...

Latest answer posted November 8, 2008 10:46 am UTC

3 educator answers

Geology

Describe the structure and characteristics of the vegetation of tropical rainforests?  

Tropical rainforests, which are located near the equator in parts of South America, Central America, Mexico, the Caribbean, parts of Asia and Africa and Australia have warm temperatures that...

Latest answer posted April 15, 2012 2:39 pm UTC

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Geology

Why is the study of layers of sedimentary rocks particularly useful for the science of geochronology?

Studying layered sedimentary rocks is precisely the point of geochronology. Geochronology, of course, is the scientific practice of studying rocks and fossils for the purpose of determining their...

Latest answer posted September 13, 2013 2:50 pm UTC

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Geology

Why is the movement of lithospheric plates significant?

The movement of these plates (there are about 20 of them) is significant to us today mostly because it is their movements that cause earthquakes. The lithospheric plates are the plates that are...

Latest answer posted November 4, 2009 11:08 am UTC

1 educator answer

Geology

What happens at the boundaries of tectonic plates?

The simple answer of what happens at the boundaries of plates is that they are constantly moving and their movement defines them. There are three different types of plate boundaries: convergent,...

Latest answer posted May 24, 2009 5:50 am UTC

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Geology

What is the permeability of metamorphic rock?

Permeability in metamorphic rock tends to be nonexistent, as this particular kind of rock, formed from cooling lava, is quite dense. However, where these rocks are fractured, some permeability...

Latest answer posted January 4, 2009 11:18 pm UTC

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Geology

What is field evidence to recognise geological faults?

When you are looking at exposed layers of rock, as on the side of a cliff, the layers are usually just that--lines of rock, one on top of another, over long periods of time. Each layer is generally...

Latest answer posted November 14, 2009 1:03 am UTC

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Geology

How can CFCs affect the atmosphere and life on earth?

In the stratosphere, oxygen can exist as ozone, or O3. Different wavelengths of ultraviolet (UV) light help combine and dissociate the ozone molecule by adding or removing atomic oxygen:O + O2 +...

Latest answer posted November 25, 2008 6:23 am UTC

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Geology

Describe the changes in air pressure that occur during an El Nino year. How do these changes affect wind...

During a year with the El Nino effect, there is warming of the surface waters in the eastern Pacific Ocean and the pressure is high in the western Pacific. The opposite is true in years when the...

Latest answer posted January 30, 2010 9:54 am UTC

1 educator answer

Geology

What is the fold in which the oldest layer of rock is in the center? 

In the study of geology there are three main layers of folds in the earth. " Anticlines: This is when layers are folded upwards in what looks like an arch. The layers are symmetrical (look...

Latest answer posted October 23, 2008 11:54 am UTC

1 educator answer

Geology

What are the forces that cause rock to break down? nothing

In a word, erosion. The action of the weather on exposed rock surfaces exposes them to water in its various states (solid ice, liquid water, and if you deep enough underground where the...

Latest answer posted November 24, 2008 8:19 pm UTC

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Geology

Was the cycle of supercontinent formation and destruction initiated by the Theia collision? The name "Theia" has been...

The first theorized supercontinent, Vaalbara, apparently formed 3.1 to 3.6 billion years ago (http://www.statemaster.com/encyclopedia/Vaalbara) The Theia collision is assumed to have occured 4.5...

Latest answer posted January 27, 2010 8:50 am UTC

2 educator answers

Geology

What is the difference between Dusk and Twilight?

According to Webster’s Dictionary twilight is the diffused light from the sky during the early evening or early morning when the sun is below the horizon and its light is refracted by the earth's...

Latest answer posted November 23, 2008 12:12 pm UTC

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Geology

What is meant by isostasy?

The Earth’s lithosphere, which is the crust and upper most part of the upper mantle, is broken into tectonic plates which float in the more viscous asthenosphere, which is the remaining part of the...

Latest answer posted December 24, 2010 1:10 am UTC

1 educator answer

Geology

What is a transform fault?

A "transform fault" is a fault line where two tectonic plates slide against each-other. Not all faults are transform faults. Some plates separate and allow magma to seep up and like a scab,...

Latest answer posted November 23, 2009 3:10 am UTC

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Geology

How were  scientists able to arrive at the distinct layers of the earth?

Human knowledge of the earth's core has been developed over time, by means of a number of tools. Once people learned that earthquakes generated seismic waves, they began to track them. They found...

Latest answer posted November 5, 2008 11:04 pm UTC

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Geology

Why does the tidal bulge extend in 2 directions? Why does the tidal bulge extend in the direction away from the Moon...

The Earth-Moon system, or the "double planet" nature of these two bodies, is unique in the Solar System, and may be quite rare as planetary bodies go. The reason is that the size of the Moon...

Latest answer posted March 1, 2010 12:22 am UTC

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