earthquakes and volcanoes Flashcards
convection currents
causes the crusts plates to move together, pull apart and push past one another
constructive (divergent) plate boundary
two plates move apart from eachother, causing sea-floor spreading, new oceanic crust is formed e.g. mid atlantic ridge
convergent (destructive) plate boundary
the oceanic crust moves towards continental crust and is forced underneath continental crust since oceanic crust is denser, deep sea trenches and island arcs are formed
conservative plate boundary
two plate slip sideways past each other
caldera volcano
a large mass with a crater where the summit would be
composite volcano
triangular, pyramidal in shape
shield volcano
low, wide not as distinct
fisher volcano
long and narrow, may appear like a crack in the ground
distrubution of volanoes
-3/4 of the wolrds active volcanoes are located in the pacific ring of fire
-most of them are under the ocean
impact of volcanic eruption
-crop failure
-mudslides
-floods
-wildfires
-drinking water contamination
-power outages
-human illness
-animal death
-destruction- pyroclastic flow
-human death- burns and injuries
impact of earthquakes
-interuption of water supplies
-destruction of infrastructure
-breakage of sewage disposal systems
-loss of public utilities, electricty, gas
-floods from collaspased dams
-release of hazardous material
-fires
-spread of chronic illeness
-tsunamis
-landslides and rockfall
-mudflows and debris flows
benefits of voclanoes
-tourism
-fertiles soi l from volcanic ash, increases profit for farmers, high yield crops
-geothermal energy can be harnessed
-minerals in lava, gold and diamond, can be mined to make money
-buildings can be made from lava rock, building materials
-land formation
process of a volcanic eruption
-as a result of convection currents and plate tectonics, magma and pressure builds up within the magma chamber
-earthquakes takes place in surrounding area
-acidity of surrounding water increases, relases of gas, water is undrinkable
-increase of amount of harmful gases in atmosphere
-pressure on volcanoes, shape is altered
-steam vent will burst
-pressure will trigger explosion, releases all force
predicting volcanoes
-seisometers
-chemical sensors, measure increased sulfur levels
-lasers, detects physical swelling of volcano
-ultrasound, monitor low frequency waves in magman
how are safe houses built
-light roofs
-reinforced walls
-light walls and gables
-small windows
-shock absorbers
-confined masonry
