Eggs 107 exam 1

What is the population on Earth

About 8 billion

Who has the most insurance losses from natural disasters?

USA

Population density and natural disasters in Asia

d]Densely populated areas are often more susceptible to the impacts of natural disasters, especially in regions like Asia.

What are return period of events?

An average time or an estimated average time between events, such as earthquakes, floods, and landslides.

Pandemic

-The COVID-19 pandemic has shown how health crises can compound the effects of natural disasters, straining emergency response systems.

-Pandemics can disrupt supply chains and emergency services, making it harder to respond effectively to natural disasters.

What is the age of the Earth?

4.5 billion years old

What is lithosphere?

the rigid outer part of the earth, consisting of the crust and upper mantle.

What is asthenosphere?

-The upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

What is mesosphere?

The strong, lower part of the mantle between the asthenosphere and the outer core.

What is core?

Center of the earth

What is Pangea?

scientists believe that the continents were all part of one huge land mass called Pangea millions of years ago.

What is the age of ocean crust?

340 million years old

What are divergent margins?

Two plates mover a part relative to one another and in most cases magma fills the space between the plates.

What are convergent margins?

Places where two lithospheric plates collide with each other.

What are transform boundaries?

When two plates slide past each other

Plate tectonics and natural disasters

They can cause earthquakes.

What is the relationship between plate edges and hazards?

Movement in narrow zones along plate boundaries causes most earthquakes.

Subduction process on convergent margins

They can cause earthquakes that go down to 700km

Subduction of oceanic crust and density

Subduction is possible because the cold and rigid oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle.

What is ductile behavior?

A body of rock under high pressure

What is brittle behavior?

A body of rock to which a sudden, rapid stress has been applied.

What are causes of Earthquakes

movement along tectonic plates

What is Epicenter?

the point on the surface directly above the focus

What is the hypocenter?

the underground focus point of an earthquake.

Which wave arrives first?

P wave

What are the body waves?

P and S waves

What are the surface waves?

Rayleigh and Love waves

How do we determine the location of epicenter?

Where the three stations overlap/meet is the location of the epicenter of the earthquake.

What are surface waves

seismic waves that travel along the Earth's surface

Love waves

move side to side

Rayleigh waves

rotate backwards

Horizontal motion of buildings

Buildings arent designed for a strong vertical forces

What is seismic gap?

An area along a fault where there has not been any earthquake activity for a long period of time.

what is liquefaction?

The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud

What is the state with the largest number of earthquakes?

Alaska

Seismic energy and propagation in the eastern U.S. vs. western US

The crust in the east is much older which means they have been exposed to extreme pressures and temperatures, making them harder and often denser.

Hawaii earthquakes

They are from magma movement

What types of volcanic activity are there?

divergent, convergent, hotspot (convergent are big eruptions)

Silica tetrahedra and viscosity

The more silica tetrahedra the higher the viscosity

Most abundant volatile in magma?

water

What is decompression melting

the upward movement of the earth's mantle to an area of lower pressure, once the pressure is lowe it starts to melt

What are the 3 V's

volume, velocity, volatiles (controls how violent a volcano is)

What is viscosity?

amount of silicon

What is volume?

The amount of material

What is volatiles?

gas

Caldera formation

When the magnatude is empty

active volcano

One that is erupting or shows signs that it may erupt in the near future.

dormant volcano

A volcano that has not erupted for a long time, but may erupt again one day.

extinct volcano

A volcano that has not erupted for thousands of years and probably will not erupt again.

What is pyroclastic debris?

fragmented material that sprayed out of a volcano and landed on the ground or sea floor in solid form

pyroclastic flow causes

from explosive volcanos