Question | Answer |
Risk | The potential danger or damage created by an event |
Short term | A hazard lasting for a short period (less than a day) |
Medium term | A hazard that lasts for a few weeks |
Long term | A hazard that lasts for over a month |
Tectonic | Associated with the movement of the tectonic plates in the Earth's crust |
Natural hazard | A danger or threat to HUMAN LIFE caused by natural processes such as climatic change or tectonic activity |
Prediction | Volcanoes can me monitored to warn of an eruption |
Protection and preparation | Can be as effective as prediction in reducing impact |
Plate | Also called a tectonic plate. The Earth's crust is broken into huge slabs of rock |
Oceanic crust | Crust below the oceans. Mainly basalt, it is younger, heavy and dense |
Continental crust | Less dense crust forming continenets (25-90km thick) Floats on the mantle |
Core | The centre of the earth |
Mantle | THe layer of semi-molten rock between the Earth's crust and core |
Magma | The molten rock below the Earth's surface |
Convection currents | The slow circular movements of molten rock in the mantle caused by the heat rising from the Earth's crust |
Crust | The solid layer of rock around the outside of the earth |
Plate margins/boundaries | Where two plates meet |
Island arcs | A chain of volcanic islands formed along a Subduction zone |
Ring of fire | A line of volcanoes following the destructive plate boundaries around the side of the Pacific Ocean |
Mid oceanic ridge | A long undersea mountain chain formed on a constructive plate boundary (eg. Iceland is on the Mid Atlantic Ridge) |
Ocean trench | A long deep valley in the ocean floor. Ocean trenches are formed at destructive plate boundaries. |
Destructive margin | An oceanic and continental plate are moving towards each other. The oceanic plate will sink |
Subduction zone | Area where an oceanic plate is sinking, melting and being destroyed at a destructive plate boundary |
Fold mountains | Mountains formed by the bending and buckling of rocks, where two tectonic plates are colliding |
Sedimentary rocks | Rock formed from particles of sediment which have been compressed and cemented together |
Constructive margin | Tectonic plate boundary where new oceanic crust forms |
Collision margin | The place where two continental tectonic plates collide. The plates are not dense enough to sink into the mantle and therefore both crumble to form fold mountains |
Conservative margin | Two plates are sliding past each other |
Pyroclastic clouds | A cloud of extremely hot gas, ash, lava fragments and rock which is ejected during a volcanic eruption and runs down the side of a volcano |
Volcanic bombs | A lump of lava which is thrown high into the air when a volcano erupts |
Active volcano | A volcano which has erupted recently and is expected to erupt again in the future |
Long term effects | Impacts which develop later, such as fall in global temperatures |
Lahar | Mudflow or debris flow originating on a volcano |
Albedo effect | Refelection of the sun's rays by particles in the atmosphere - leads to cooler temperatures |
Short term effects | he initial impact of the volcano |
Lava | The molten rock which is erupted from a volcano |
Acid lava | Thick and sticky lava thrown out by some volcanoes, mainly along destructive plate boundaries |
Basic lava | Thin and runny lava thrown out by some volacnoes, mainly along constructive plate boundaries |
Shield Volcano | Volcanoes which are wide and low with gently sloping sides due to basic lava |
Tsunami | A huge wave triggered by an earthquake |
Aftershock | A small earthquake following a major earthquake |
Secondary effects | Long term impacts such as businesses closing |
Richter scale | Size of earthquakes is measured on a 9 point scale; level 2 is 10 times the size of level one |
Primary effects | The immediate impact of the earthquake |
Epicentre | The place on the Earth's surface which is directly above the focus of an earthquake |
Focus/hypocentre | THe point below ground where an earthquake begins |
Seismometer | These machines detect vibrations beneath the Earth's surface. Readings are passed to a seismograph |