What difference does the depth of the focus make?
Less energy is released during a shallow focus earthquakes, while tremendous energy accumulates during a deep focus earthquake. However, the annual total energy released from the frequent shallow focus earthquakes exceeds that released from fewer happening deep focus earthquakes.
Is shallow or deep earthquake worse?
Quakes can strike near the surface or deep within the Earth. Most quakes occur at shallow depths, according to the U.S. Geological Survey. Shallow quakes generally tend to be more damaging than deeper quakes. Seismic waves from deep quakes have to travel farther to the surface, losing energy along the way.
At what depth do most earthquakes occur?
Earthquakes can occur anywhere between the Earth’s surface and about 700 kilometers below the surface. For scientific purposes, this earthquake depth range of 0 – 700 km is divided into three zones: shallow, intermediate, and deep.
What is the depth of focus in the shallow earthquake?
What is the depth of focus in the shallow earthquakes? Explanation: In the shallow earthquakes, depth of focus lies anywhere up to 60 km below the surface. A great majority of the earthquakes in the past had been of this type.
What is the maximum depth of focus observed till date?
What is the maximum depth of focus observed till date? Explanation: As regards the distance from epicenter to focus, or depth of focus, it has been observed from the study of seismic records that no earthquake with a focus deeper than 700 km has been recorded so far.
What type of plate boundary is closest to the earthquake with the deepest focus depth?
The deepest earthquakes occur within the core of subducting slabs – oceanic plates that descend into the Earth’s mantle from convergent plate boundaries, where a dense oceanic plate collides with a less dense continental plate and the former sinks beneath the latter.
Is there a relationship between the depth of the earthquake and the boundary near it?
1. It is relatively easy to see the relationships between earthquakes and the plate boundaries. Along divergent boundaries like the mid-Atlantic ridge and the East Pacific Rise, earthquakes are common, but restricted to a narrow zone close to the ridge, and consistently at less than 30 km depth.
Do earthquakes happen at convergent boundaries?
About 80% of earthquakes occur where plates are pushed together, called convergent boundaries. Another form of convergent boundary is a collision where two continental plates meet head-on. Since neither plate is stronger than the other, they crumple and are pushed up.
Do volcanoes happen at convergent boundaries?
Volcanoes are one kind of feature that forms along convergent plate boundaries, where two tectonic plates collide and one moves beneath the other. If two tectonic plates collide, they form a convergent plate boundary. Usually, one of the converging plates will move beneath the other, a process known as subduction.
Why do continents not Subduct?
It is due to the process of subduction; oceanic crust tends to get colder and denser with age as it spreads off the mid-ocean ridges. It gets so dense, that it sinks in the upper mantle (subduction). As the continental crust is lighter than the oceanic crust, the continental crust cannot subduct.
Which boundary can produce volcanoes?
divergent plate boundaries
Is it safe to live on the Ring of Fire?
Many people risk living on or near volcanoes because the soil is good for farming. Volcanoes are also popular tourist attractions, which can help build up the local economy. Earthquakes can cause serious structural damage to buildings and can be deadly to citizens, especially during the aftershocks.
What causes a volcano to form?
Volcanoes are vents, or openings in Earth’s crust, that release ash, gases and steam, and hot liquid rock called lava. When the lava cools and hardens, it forms into the cone-shaped mountain we think of as a volcano. On land, volcanoes form when one tectonic plate moves under another.
How long does a volcano take to form?
approximately 000 years
What is Volcano short answer?
A volcano is an opening in the earth’s crust through which lava, volcanic ash, and gases escape. Beneath a volcano, liquid magma containing dissolved gases rises through cracks in the Earth’s crust. As the magma rises, pressure decreases, allowing the gases to form bubbles.
Why do magmas rise to the surface?
As they rise, gas molecules in the magma come out of solution and form bubbles and as the bubbles rise they expand (as outside pressure gets lower). Eventually the pressure from these bubbles is stronger than the surrounding solid rock and this surrounding rock fractures, allowing the magma to get to the surface.
Which component of magma is the highest and lowest in value?
Felsic magma has the highest silica content of all magma types, between 65-70%. As a result, felsic magma also has the highest gas content and viscosity, and lowest mean temperatures, between 650o and 800o Celsius (1202o and 1472o Fahrenheit).
Which kind of eruptive activity is highly explosive?
geo quiz 6
| Question | Answer |
|---|---|
| Spreading center volcanism most generally produces rocks that are ________. | basaltic in composition |
| Which kind of eruptive activity is most likely to be highly explosive? | eruptions of big, continental margin, composite cones or stratovolcanoes |
Is Magma hotter than lava?
Magma is hotter than lava, depending on how recently the lava reached the surface and if the magma and lava are from the same magma chamber below the…