Hazardous Earth Flashcards
(31 cards)
What are plate tectonics
The Earth’s crust is made up of a number of large plates that are moving in constant, slow motion.
What was Pangea
This was when all plates where joined together into a single continent called Pangea.
What are the different types of plate boundaries
Divergent, Conservative and collision plate boundaries.
What is a Composite Volcano
A very steep volcano which is formed at a destructive boundary.. The magma under the surface has high silica and is very explosive - these are the most dangerous volcanoes.
What is the Oceanic crust
Oceanic crust is the part of the Earth’s crust that makes up the seafloor. It’s thinner, denser, and simpler in structure than the continental crust.
What is the subduction zone
Subduction zones are where Earth’s tectonic plates dive back into the mantle
What is the destructive plate boundary
A destructive plate boundary, also known as a convergent boundary, is a region where two tectonic plates are colliding with each other.
What is the continental crust
The continental crust is the layer of granitic, sedimentary, and metamorphic rocks, which form the continents and the areas of shallow seabed close to their shores (continental shelves).
What is a plate boundary
What is a plate boundary
What are fold mountains
Fold mountains are created where two or more of Earth’s tectonic plates are pushed together
What is an Ocean Trench
Ocean trenches are steep depressions in the deepest parts of the ocean
What is a Convergent plate boundary
When two plates come together, it is known as a convergent boundary. The impact of the colliding plates can cause the edges of one or both plates to buckle up into mountain ranges or one of the plates may bend down into a deep seafloor trench.
What are divergent plate boundaries
A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth’s mantle to the surface, solidifying to create new oceanic crust.
What are collision plate boundaries
If two continental plates collide, neither can sink and so the land buckles upwards to form fold mountains.
What are the 2 ways to measure earthqakes
Measuring by magnitude and measuring by damage.
What is the Richter Scale
The Richter scale can be used to measure the magnitude (power) of a tremor using an instrument called a seismometer.
What is the logarithmic scale
A logarithmic scale is a scale used to mesure earthquakes for the Richter Scale. If the size of the earthquake is a 6 on the scale a 5 is 10 times smaller than the 6.
What is the Mercalli Scale
The Mercalli scale rates an earthquake’s intensity based on observations of the damage on a scale of 1 to 12.
What are the 4 types of shockwaves
Primary waves, Secondary waves, Surface waves -love wave and Surface waves - Rayleigh wave.
What is an earthquake
Earthquakes are vibrations of the Earth’s crust caused by movment at plate boundaries and major fault lines.
What is the Epicentre of an Earthquake
The point on the earths surface directly abouve the focus of an earthquake
What is the fault line of an eartrhquake
A line on the earths surface that traces a geological fault.
What is the focus of an earthquake
The point in the earths crust where the earthquake happens.
What are the shockwaves of an earthquake
Powerful shockwaves are released from the focus. Primary waves travel forwards and backwards and move quickly. Secondary waves are slower and move sideways and up and down.
