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Geophysics
The study of Earth using the combination of Geology and Physics, it lets us understand what is going on under the Earth's surface. Find questions on different types of seismic activities such as earthquakes and volcano eruptions here.
1,480 Questions
How did plate tectonics create dramatic changes in the continental land mass during the mesozoic?
During the Mesozoic era, plate tectonics caused the breakup of the supercontinent Pangaea into smaller landmasses, leading to the formation of the Atlantic Ocean. This movement of tectonic plates resulted in the opening of ocean basins, the emergence of mountain ranges such as the Rockies and the Andes, and the creation of new environments that influenced the evolution and distribution of organisms.
What are three explanations that support Wegener's theory of continental drift?
- Matching geological formations and fossil evidence on different continents, such as the similarity of mountain ranges and the distribution of plant and animal species, support the idea that continents were once connected.
- The fit of continental coastlines, such as the jigsaw-like fit of South America and Africa, suggests that they were once part of a single landmass.
- Evidence of past glaciation patterns and magnetic alignment of rock layers provide further support for the movement of continents over time.
Which type of seismic waves cannot be detected on the side of Earth opposite an earthquake?
Surface waves, such as Love waves or Rayleigh waves, are the seismic waves that cannot be detected on the side of Earth opposite an earthquake. These waves travel along the Earth's surface and are responsible for causing most of the damage during an earthquake.
During the laki eruption in 1783 how fast did the cloud of gas spread across Europe?
The cloud of gas from the Laki eruption in 1783 spread across Europe at a rate of about 20-25 miles per hour. It led to widespread environmental and health impacts, including poor air quality and crop failures.
Is a mineral formed from magma or lava or through evaporation or precipitation?
Minerals can be formed from magma or lava through cooling and crystallization processes, resulting in igneous rocks. Minerals can also form through evaporation of water solutions, leading to precipitation of dissolved ions and the formation of sedimentary rocks. Additionally, minerals can precipitate from volcanic gas emissions, hydrothermal fluids, and metamorphic processes.
Where can the Aurora Borealis be found?
The aurora is a glow observed in the night sky, usually in the polar zone.
For this reason some scientists call it a "polar aurora" (or "aurora polaris"). In northern latitudes, it is known as "aurora borealis" which is Latin for "northern dawn" since in Europe especially, it often appears as a reddish glow on the northern horizon as if the sun were rising from an unusual direction.
The aurora borealis is also called the "northern lights". The aurora borealis most often occurs from September to October and March to April. Its southern counterpart, "aurora australis", has similar properties.
The cause of the aurora is charged particles from the solar wind, accelerated by the Earth's magnetic field, colliding with atoms in the upper atmosphere causing them to glow as they release their surplus energy.
Energy drawn from heated water within earths crust is called?
Geothermal energy is from heated water within the earth's crust.
What did the continental drift hypothesis state?
Based on an apparent fit between Africa and South America Wegener hypothesized that at one time all continents were joined together in a "subcontinent" called Pangaea. The super-continent eventually broke into the smaller continental. which then "drifted" towards their present positions. Wegener supported his hypothesis by using circumstantial evidence, similar to the way that a detective would collect. evidence to solve a crime. There are four lines of evidence:
When is the Iceland volcano ash expected to come down?
The timing for volcanic ash to settle after an eruption can vary depending on the size of the eruption, wind patterns, and altitude. Typically, the ash can remain in the atmosphere for days to weeks before settling on the ground. It is advised to follow updates from local authorities and meteorological agencies for specific information on the Iceland volcano.
What are affects of Mount Teide Eruption in 1909?
The 1909 eruption of Mount Teide in Tenerife, Spain, caused significant ash fall and pyroclastic flows, leading to the evacuation of nearby villages. It also temporarily disrupted air travel and agricultural activities in the region. Despite the eruption's intensity, there were no casualties reported.
What is the opening in the earth's crust that allows magma to reach the surface?
An opening in the Earth's crust that allows magma to reach the surface is called a volcano. Volcanoes can be found along tectonic plate boundaries where the Earth's crust is weak, allowing magma from the mantle to rise and erupt onto the surface.
What is magma that squeezes into vertical cracks between rocks and then hardens is called?
The magma that squeezes into vertical cracks between rocks and then hardens is called a dike. Dikes are tabular bodies of igneous rock that cut across the existing rock layers.
Which direction does the earth's pole tilt in november?
In November, the Earth's north pole is tilted away from the Sun, leading to cooler temperatures in the northern hemisphere and longer nights. This tilt is what causes the changing seasons as the Earth orbits the Sun.
Which piece of evidence did wegener use to support his theory on continental drift?
Because he found fossils of plants that has heavy seeds and cant travel with seeds across oceans on a lot of the continents that are separated by oceans. Also, he found an oceanic animal that is only fresh water on parts of land that are separated by salt water. The fossils of the fern like plant was called Glossopteris
Why do people not notice that continents drift?
The movement of continents is very slow, around 1-5 centimeters per year, so the changes are not obvious on a human timescale. Additionally, the process of continental drift occurs over millions of years, making it difficult for people to perceive the gradual movement without specialized instruments. The concept of continental drift was only widely accepted relatively recently in the field of geology.
The covering of coarse particles left on the surface after finer particles are carried away by wind and running water is called "desert pavement". It forms a layer of tightly packed pebbles or cobbles that helps protect the underlying soil from further erosion and weathering.
What is the Earth's plates are presently drifting on?
The Earth's plates are presently drifting on the semi-fluid asthenosphere layer of the mantle. This movement is driven by the heat generated from the Earth's core and the process known as mantle convection.
Seismic refers to activities or phenomena related to earthquakes and the propagation of waves through the Earth caused by sudden movements within the Earth's crust. It includes studies of earthquakes, seismic waves, and the behavior of Earth's structure in response to these vibrations.
4 things that match up to support continental drift?
The first criteria is that the continents have similar shapes that coordinate with each other. For example, Africa and South America fit into each other, when rotated.
The next proof is that there were fossils of the same type of dinosaur on adjacent continents. (South America and Africa)
The third proof is that there are mountain ranges of similar build on opposite continents
The last proof is old traces of ice that all coordinate with Antarctic ice, prooving the situation that the continents were once in.
I know three if this helps...
Climate
Fossils
Jigsaw
Proofs Of Continental Drift
1. The jigsaw fit between South America and Africa.
2. Fossils of the same plants and animals are found on both South America and Africa.
3. Mountains of similar age and structure are found on both sides of the Atlantic Ocean.
4. Evidence that ice sheets once covered southern Africa, India, Australia and South America/Coal deposits under Antarctica suggesting there was once lush vegetation there meaning Antarctica had not always been where it is today.
Evidence for continental drift comes from three things. First, plate movement has been observed over fault lines. Next, the mid-oceanic trenched have been observed to extrude rock outwards. Finally, the fossil record shows species that span several continents that could not have happened from migration.
1. Fit of the Coninents
2. Fossil Evidence
3. Rocks and Mountain Ranges
4. Climate Evidence
The different continents look like they fit together, like a giant jigsaw. People believe they did, and call this super continent Pangaea. There are also prehistoric animal fossils that have been found in one place, and then found somewhere else halfway around the world.
The theory of plate tectonics explains the formation of movement and subduction of earths layers?
Plate tectonics describes the movement of Earth's lithosphere, or outer shell, which is divided into several large and small plates that float on the semi-fluid asthenosphere beneath. These plates can collide, move apart, or slide past one another, leading to phenomena like earthquakes, volcanoes, and mountain building. Subduction occurs when one tectonic plate slides beneath another, usually involving an oceanic plate descending below a continental plate.
Why did you refrigerate the gelatin cultures before observing them for liquefaction?
To indicate whether gelatin had been hydrolyzed by those cultures or not. If gelatin hydrolysis occurs, liquefaction occurs even afterrefrigerationto indicate a positiveresult. If gelatin hydrolysis does not occur, the gelatin will solidifies afterrefrigeration
The trace that records an earthquake from seismic instruments?
The trace that records an earthquake from seismic instruments is known as a seismogram. It shows the ground motion as a function of time, with peaks corresponding to the arrival of seismic waves generated by the earthquake. Seismologists analyze seismograms to determine the earthquake's location, magnitude, and depth.
Are the continents still drifting apart?
Continental drift theory has been replaced by the science of plate tectonics, an all inclusive explanation of the process of continent movements, crust creation, lithologies, subduction, the rock cycle, and so on.
At colliding plate boundaries, the more dense oceanic plate is subducted underneath and in a downward motion from the less dense plate, and enters the mantle. As it subducts, it pulls the plate attached to it. On the opposite side of the plate, new crust is being created by rising solidifying magma to fill the void created by the diverging plate boundary. Thus the plates are in a constant state of motion relative to each other; colliding, separating, or sliding past each other.
The engine behind plate tectonics is heat from the interior of the Earth. This heat exists due to radioactive decay as well as remnant heat from Earth's formation processes.
The continental drift is basically caused by the convection in the mantle.
How is earths tilt maintained?
In the short term, nothing changes the Earth's tilt much.
The Earth's tilt is fixed at about 23.5 degrees, except for very small variations.
Earthquakes and other things can have minute effects.
However, scientists believe that the tilt does change by a degree or more, over millions of years. These changes are because of the effects of gravitation within the solar system.
The ecliptic is the plane of the Earth's orbit around the Sun. The orbital planes of most of the other planets are fairly close to the ecliptic; that's probably because our solar system was formed from a rotating disk of gas and dust when gravity caused it to collapse. We would expect some differences, but probably not great differences, in this "accretion" model.
Each of the planets spin on their axes. The spin speed and the axis of spin were determined when the planets formed, or shortly thereafter. One thing that might change the spin axis of a planet would be if it collided with another planet or nearly-planet-sized body. If the collision weren't perfectly "head on", then there would be some, perhaps a LOT, of spin imparted to the combined body. It may be coincidence, but we believe that the pre-Earth collided with another planet perhaps nearly the size of Mars shortly after the formation of the solar system. The planetary cores would have merged, and we believe that much of the mass blasted off the Earth might have coalesced to form the Moon. This would explain the unusually large iron core of the Earth as opposed to other planets, the existence of the Moon, and might have contributed to the direction and speed of the Earth's rotation.
For the last 4+ billion years, the only thing affecting the Earth's spin has been the gravitational and tidal interactions with the Moon. The Earth's rotation is slowing down, VERY slightly; in a few (hundred?) million years, the day may be 25 hours long. The rotational energy of the spinning Earth is being transferred, EVER so slowly, to the orbital altitude of the Moon. The Moon is receding from the Earth. Eventually, the Earth will become tidally locked with the Moon, and the two with spin forever facing each other. This may require another billion years or so, so it isn't anything that we or our human ancestors will need to worry about.
And when that time comes, we'll probably have other things to worry about - like the expanding Sun. We'll want to pick up the Earth and move it outward a bit; perhaps we'll grab Mars along the way, and give ourselves an extra-large Moon2 to go along with the original Moon.
