Science-Danger zone

Plate tectonic Theory

Theory that states that the earths crust is broken up into several pieces called tectonic plates. The edges of these plates are called plate boundaries. Plates move due to molten rock in the mantle.

Impacts of tsunamis on the lithosphere?

Tsunamis erode the earth as water surges. The water gathers rocks and sand as the water surges and spreads them across the land. Tsunamis can also change landforms due to the extremity of the water surges.

Theory of Continental Drift was developed by

Alfred Wegener

What does the theory of continental drift state

Theory that suggests that all of the continents were once joined together, into a supercontinent called "Pangaea". It suggests that the continents have changed their position in the past and are moving now.

What is the name of the two land masses Pangaea was split up into?

Laurasia and Gondwana.

Evidence for Continental Drift

1) continental fit, 2) coloration of fossil plants and animals, 3) coloration of rock sequences, 4) paleoclimate data

What are convection currents?

The molten rock in the aesthenosphere moves around depending on its temperature. At the bottom of the mantle, close to the outer core the molten rock gets heated up. Because heat rises, the hot molten rock moves back up towards the surface of the Earth. As it rises, it begins too cool. The cooler molten rock sinks back down towards the center of the Earth and the cycle will begin again. This is known as convection currents.

What is another driving current of convection currents?

The temperature of a substance will impact its density. When something is heated, the substance gain kinetic energy and this causes it to become less dense. When a substance becomes denser it will rise as its not affected by gravitational forces. When a substance is cooled it loses kinetic energy and this causes it to become more dense. When a substance becomes denser it will fall down due to gravitational forces. The change density of density in the magma and the impact gravitational forces have on it , drive convection currents.

What causes convection currents?

Heating and cooling of the fluid, changes in the fluid's density, and the force of gravity combine to set convection currents in motion.

How do convection currents move plates?

Convection currents act as conveyor belts to carry plates. Currents and Plates move in the same direction.

What is a fault?

A fault is when there is movement of the rocks on either side or both sides of a crack in the surface of the earth. E.g. San Andres fault

What is a fold?

A bend in layers of rock that form due to pressure from the sides. E.g. The Himalayan Mountain

What is a plate boundary?

the boundary where two tectonic plates meet

What are the 3 types of plate boundaries?

divergent, convergent, transform

What is a convergent plate boundary?

occur when two plates collide together and push into each other.

What happens if the convergent boundaries are both continental plates?

Convergent boundary will cause mountains to form. E.g. Himalayan Mountains

What happens if the convergent boundary has a continental plate and oceanic plate?

It will form a subduction zone. This occurs because the oceanic plate is more dense then the continental plate. They will often form volcanoes and trenches. E.g. Marina Trench

What is a subduction zone?

Where on plate moves under the other plate.

What is a divergent boundary?

Occurs when two plates are moving away from each other. When they move away from each other they from mid-ocean ridges. New crust can also be made as molten rock from the mantle rises, cools and hardens to become crust. E.g. The mid-Atlantic ridge.

What is a transform boundary?

when two plates slip past each other, moving in opposite directions. Often cause earthquakes as the plates scrape against each other.

What is an Earthquake?

An earthquake is the result of a sudden release of stored energy in the form of seismic waves in the Earths crust.

How do earthquakes from?

An earthquake occurs when there is friction between rocks, which builds up pressure. When the pressure becomes too great, the slabs of rock snap, releasing a massive pulse of energy, causing an earthquake.

Impacts of earthquakes on the lithosphere

creates ground cracks, landslides, avalanches, fires, and severe building damage.

Impacts of earthquakes on hydrosphere

causes nig waves in the ocean causing destruction to land and significantly disrupting marine life and costal communities.

Impacts of earthquakes on biosphere

can cause buildings to collapse, which can bury people beneath the rubble or cause death. Can cause damage to infrastructure leaving people without homes, clean water and power. Diseases can also break out due to infections from injuries and lack of clean water.

What are the 2 ways earthquakes are measured?

The Richter scale and the Mercalli scale.

What are the 3 groups seismic waves can be classified into?

P-waves , S-waves , L-waves

What is the epicenter of an earthquake?

The exact point an earthquake strikes below the earths surface.

What is a tsunami?

A tsunami is a huge wall of water that is caused by an earthquake.

How causes a tsunami?

Caused by a large displacement of water. This displacement is caused by underwater earthquakes or volcanic explosions. As waves approach the land the speed of the waves decrease but their height increases.

Impacts of tsunamis on the biosphere?

Intense walls of tsunamis can kill organisms and damage habitat both on land and in sea. Strong waves and fast moving debris can lead to lose of life and injury. It can lead to death of many species such as animals, plants and humans.

Impacts of tsunamis on the hydrosphere?

Water surges from tsunamis lead to destruction. Water becomes polluted sue to the waves pulling the sewage and industrial chemicals back into the ocean. This leads to the water polluting freshwater sources and making them poisonous and not safe for consumption.

What is a volcano?

A volcano is an opening in the Earth's crust where magma reaches the Earth's surface.

How do volcanoes form?

Volcanoes are formed when magma from within the Earth's upper mantle works its way to the weakened surface. At the surface, it erupts to form lava flows and ash deposits. Over time as the volcano continues to erupt, it will get bigger and bigger.

What are the two types of volcanoes?

Composite and Shield. Composite volcanoes are cone-shaped volcanoes built of layers of lava and ash whilst shield volcanoes are round shaped volcanoes that have runny lava.

What is a constructive plate margin?

When two plates move away from each other

What is a destructive plate margin?

where two plates are moving towards each other

What happens at a constructive plate margin?

The two plates slowly move away from each other and overtime allows the extremely hot magma to rise between the plates to form new crust. Magma can sometimes rise up and erupts.

What is the ring of fire?

The active volcanoes that are along the margin of the pacific plate.

What is the difference between magma and lava?

Magma is molten rock located below the surface; lava is molten rock erupted above ground.

What is the difference between an extinct and dormant volcano?

A extinct volcano hasn't erupted for thousands of years whilst a dormant volcano is considered to be "asleep" and can erupt at any time.

Impacts of Volcanoes on the atmosphere?

Ash is pumped into the atmosphere during an eruption. Planes are not able to fly through ash so flights are cancelled. Gases such as sulfur dioxide and carbon dioxide are also released and can have affects on the atmosphere and weather.

Impacts of volcanoes on the biosphere?

Lava that flows out during a eruption can kill people , animals and destroy plants and start huge fires which cause more deaths.

Impacts of volcanoes on the lithosphere?

Volcanoes can produce new islands from ash and rocks that come out during an eruption. Lava flows can both destroy landforms and create new ones. Some chemicals that come out during an eruption are beneficial for soil and are nutrient rich allowing plants to thrive.

Impacts of volcanoes on the hydrosphere?

Sulfur dioxide from volcanic eruptions react with water in the atmosphere to form sulfuric acid which can produce acid rain or lower the pH of water. These things are bad for organisms that live in the water.

What are cyclones?

Cyclones are giant, spinning, whirlwind, storms.