what are some comparisons between earthquakes and volcanoes?

Question

compare

Answer 1

famous earthquakes and volcanoes from more recent times

for earthquakes
1737 Calcutta
1755 Lisbon
1811/12 New Madrid, Missouri
1906 San Francisco
1964 Anchorage
1989 San Francisco


for volcanoes

79 Mount Vesuvius, Italy
1783 Volcano Laki, Iceland
1815 Sumbawa, Indonesia
1883 Krakatoa
1902 Mount Pelée, Martinique
1980 Mt. Saint Helens
1985 Nevada del Ruiz (Amero, Columbia)
1986 Lake Nyos, Cameroon
1991 Pinatubo, Phillipines
1993 Mayon, Phillipines


for volcano
Swelling of the volcano signals that magma has accumulated near the surface. Scientists monitoring an active volcano will often measure the tilt of the slope and track changes in the rate of swelling. An increased rate of swelling, especially if accompanied by an increase in sulfur dioxide emissions and harmonic tremors is a high probability sign of an impending event. The deformation of Mount St. Helens prior to the May 18, 1980 eruption was a classic example of deformation, as the north side of the volcano was bulging upwards as magma was building up underneath. But most cases of ground deformation are usually detectable only by sophisticated equipment used by scientists, but they can still predict future eruptions this way.


for earthqurake
An earthquake is a phenomenon that results from and is powered by the sudden release of stored energy that radiates seismic waves. At the Earth's surface, earthquakes may manifest themselves by a shaking or displacement of the ground and sometimes tsunamis, which may lead to loss of life and destruction of property.

Earthquakes may occur naturally or as a result of human activities. In its most generic sense, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic waves.

Most naturally occuring earthquakes are related to the tectonic nature of the Earth. Such earthquakes are called tectonic earthquakes. The Earth's lithosphere is a patch work of plates in slow but constant motion caused by the heat in the Earth's mantle and core. Plate boundaries glide past each other, creating frictional stress. When the frictional stress exceeds a critical value, called local strength, a sudden failure occurs. The boundary of tectonic plates along which failure occurs is called the fault plane. When the failure at the fault plane results in a violent displacement of the Earth's crust, the elastic strain energy is released and elastic waves are radiated, thus causing an earthquake. It is estimated that only 10 percent or less of an earthquake's total energy is ultimately radiated as seismic energy, while most of the earthquake's energy is used to power the earthquake fracture growth and is eventually converted into heat. Therefore, earthquakes lower the Earth's available potential energy and thermal energy, though these losses are negligible. To describe the physical process of occurrence of an earthquake, seismologists use the Elastic-rebound theory.

Answer 2

Earthquakes and volcanos are both caused by processes taking place under the Earth's surface. The Earth is divided into a series of plates--tectonic plates (think of it like an eggshell with cracks) These plates are floating on top of the interior of the Earth. These plates are in motion, some moving feet per year while others only move centimeters per year. These plates can meet in 3 different ways causing 3 different types of boundaries. The first is divergent--this is where the plates are moving away from each other. This allows magma to emerge from the Earth and spill on the surface in a generally gentle process (not really a volcano). Examples of this is the Mid-Atlantic Ridge and the Great Rift Valley in Africa. The second kind of plate boundry is a convergent plate boundry--this is where the volcanoes and earthquakes come in. At a convergent plate boundry 2 plates collide and the lighter, less dense plate is pushed under the heavier, denser plate. The subducted plate (the one going under) is pushed below it results in earthquakes. The plate begins to melt in the hotter interior of the earth and it rises to form volcanoes. Examples of these plate boundries are centered in the "Ring of Fire" which circles the Pacific Ocean. The third type of plate boundry is a transform boundry where the plates move side-by-side. This tension that is produced as the plates try to slide by one another results in earthquakes. An example of this is the San Andres Fault in California.
To answer your question, earthquakes and volcanoes both result from convergent tectonic plate boundries.

Answer 3

They're both generated from within the earth.

Are they both triggered by heat changes?

A volcano can exist for a long time without erupting but it is active the whole while. An earthquake fault isn't "active" the way a volcano is.

An earthquake can result in major tidal changes, but those are a secondary thing; while the eruption of a volcano means the lava is sent out directly stemming from the volcano.

What I've offered are "surface level" guesses here. You may want to look into whether beneath that surface those differences may actuall result from similiarities.

Answer 4

volcanoes cause earth quakes not all erruptions happen on the surface with volcanoes that is why we have earthquakes

Answer 5

they both have to deal with the movement of plates on the Earth's surface.