Mazza/Paulino Test #3 Flashcards
Do volcanoes occur where earthquakes occur?
sometimes. Volcanoes and earthquakes usually occur at the coastline or near the water and most earthquakes appear on land than on water.
Where do new oceanic crust form?
They form at Mid-ocean ridges
How would you compare the oceanic plate and continental plates with their density and size
The continental plate is thicker and less dense than the oceanic plate
What are trenches?
It is the zone where an oceanic plate sinks beneath another plate. (deepest part of the ocean)
What are mid ocean ridges?
Mountain chain located in the middle of ocean. It’s an example of divergent boundaries and seafloor is formed. The mid-ocean ridges have the youngest rock, and the ocean floor gets older, as you move toward the continents.spreading occurs where the new ocean floor
What is the hottest layer that is solid metal and the densest layer?
The Inner core
What zone does the P wave travel the fastest through?
The MOHO layer
What causes tectonic plate movement
Convection currents
What are hot spots?
They create island chains in the middle of tectonic plates
What is the epicenter?
Point on earth’s surface directly above the earthquake
What is the focus?
Point in which the earth first moves creating a earthquake
What are plate tectonics?
A theory that states earth’s surface is composed of a number of rigid but moving parts
Where are the oldest ocean crusts formed?
Pacific and Atlanic ocean
What are divergent boundaries?
Where two plates pull apart
What are convergent boundaries?
Where two plates collide
What are transform boundaries?
Where two plates slide past each other
What are the three types of convergent boundaries?
Two oceanic plates colliding(older O submerge under young O), two continental plates colliding(both dont submerge instead they push each other up or sideways), and an oceanic and continental plate collide(O submerge under C).
What have Seismic studies of the Moon help scientists to make inferences about?
the moons interior
Where do most of the basalt that forms island arcs comes from?
the astenosphere (plastic mantle)
Which cross section best represents the relative locations of Earth’s asthenosphere, rigid mantle, and stiffer mantle? (The cross sections are not drawn to scale.)
rigid mantle, astenosphere, then stiffer mantle
What is the earth’s outer core and inner core both
inferred to be?
composed of a high percentage of iron
Which tectonic movement of Earth’s crust is most likely responsible for the East African Rift Valley in Africa.
divergence of continental crust
What is the difference between P waves and S waves
S-waves are absorbed by the Earth’s outer liquid core, meaning they do not travel to the other side. P-waves travel through allmatter, and therefore will reach the other side of Earth.
How do scientists infer about the earths layers?
they study seismic data. Seismic waves refract at each layer, meaning they change direction and also speed (speed and direction together is a vector)
How do we know for sure that the earth’s crust is in motion?
There are evidence of marine fossils found high on mountains through crustal uplift and also displaced rock that has been faulted.
What are magnetic reversals?
The Earth’s magnetic field created by the North and South Poles is recorded in the orientation of iron in rock when the rock is formed. Rock record of the ocean floor shows that the Earth’s poles have reversed over the course of the Earth’s history, showing alternating strips of ‘+’ and ‘-‘ (plus and minus) in the iron in the ocean-floor rock.
What are P and S waves?
Primary and shear waves
