Plate Tectonics Flashcards

Question

Destructive Volcanoes

Answer 1

Explosive acid volcanoes where there is subduction

Answer 2

No subduction > no Volcanicity

Answer 3

When radioactive decay at the core is concentrated, it can create localise thermal currents where plumes of magma rise vertically The hotspot remains stationary, whilst the plate moves resulting in chain islands

Answer 4

When magma solidifies in a vertical fissure | Once solidified into igneous rock, it is usually more resistant to erosion, leaving a prominent wall-like feature

Answer 5

Forms when magma solidifies into horizontal/inclined layers of existing rock

Answer 6

Form where viscous magma forcing into overlying rock strata to arch into a dome

Answer 7

Larger scale where often, the other features will feed off of them Extreme heat/ pressure (metamorphism)= metamorphic aureole

Answer 8

Gaseous emissions – steam, carbon monoxide, hydrogen sulphide, sulphur dioxide and chlorine Solids – ash, dust, glassy cinders Liquids – lava bombs (tephra/pyroclasts), solidify mid-air

Answer 9

(basaltic) is low in silica, allowing gas bubbles to move freely – fluid and free-flowing

Answer 10

rich in silica – viscous > gas bubbles cannot expand - build up of pressure = violent eruptions

Answer 11

Mid-ocean ridge, rift valleys and hotspots – direct access to surface Repeated eruptions Runny lava forms gentle sloping volcanic cones and shields

Answer 12

Destructive margins Viscous lava cannot flow far before cooling = steep convex cones Rhyolitic lava is thick and unable to flow Explosive pyroclastic flows of superheated gases, ash and pumice

Answer 13

Hasn't erupted within historic times

Answer 14

10,000 years dormant

Answer 15

Alternating eruptions of ash, tephra (incl. lapilli), lava building volcano in layers Often covered by secondary (parasitic) cones and fissures

Answer 16

Ash, cinder and tephra erupted in the central crater | Steep-sided concave in shape

Answer 17

Emptying of the magma chamber allows flanks to cave in creating a vast pit which can be flooded as a sea or lake

Answer 18

Basaltic | Gentle flow from fissures

Answer 19

Basaltic | Gentle flow from central vent

Answer 20

Frequent explosive eruptions of tephra and steam

Answer 21

Thicker basaltic + Andesitic + Rhyolitic | Less frequent, more violent eruption of gas, ash and tephra

Answer 22

Thicker basaltic + Andesitic + Rhyolitic Long periods of inactivity Very violent gas explosion

Answer 23

Andesitic + rhyolitic | Very Violent eruption of nuées ardentes

Answer 24

Rhyolitic Exeptionally violent eruptions of gases, ash and pumice Create rainstorms and lahars

Answer 25

Geysers Fumaroles Hot Springs Boiling Mud

Answer 26

Boil from contact with hot rocks Hot volcanic gases build up pressure until an explosion of water takes place The vent re-fills and it’s all repeated Short-lived features

Answer 27

Low pressure outlets of steam and gas | Solfatara when the gas is sulphurous – leaves yellow deposits

Answer 28

Not under pressure Not all volcanic Heated deep below the surface Dissolved minerals create boiling mud

Answer 29

In 1963 Powerful underwater eruptions led to the birth of a new island off the coast of Iceland As lava erupted onto the seafloor it solidified, eventually formed an island that emerged out of the water

Answer 30

Constructive plate boundary on two continental plates Magma plume below Extends 5000 Km Shield volcanoes form

Answer 31

Shows the movement of the plates since the plume of radioactive decay from the core stays in the same place, so volcanic islands form in the direction of the movement of the plate The largest island is called Big island and is where there is an active volcano Then further west smaller islands are areas where the basalt lava rock is older, therefore showing how they used to be above the plume They get smaller because they are older ad are eroded To the east of big island is Liohi, an underwater volcano which will eventually form the new island

Answer 32

Shallow focus quakes occur like San Fran 1906,1989 and LA 1994 Where the Pacific and North American late are moving parallel to each other The same direction but the pacific plate is moving about 3 times faster at 5-9 cm a year Stresses build up creating transform faults

Answer 33

Continental/Continental Tallest mountain range on earth where the Indian Plate is colliding into the Eurasian Plate Everest grows 4mm a year, predictions of up to 8 cm shift upwards since the April Nepalese Earthquake 2015

Answer 34

Caribbean plate slips under the South American | Dramatic heat at Benioff zone creates the chain of volcanic islands known as the Lesser Antilles

Answer 35

Subduction of oceanic Nazca plate below continental South American Plate The rise of the Andes is down to compression from the Nazca Plate and the Antarctic Plate creating fold mountains The Peru- Chile Trench is a depression where the Nazca plate is subducting

Answer 36

African rift valley, main crater is 250m deep, containing a lava lake Frequent! Along with its neighbouring volcano, it is responsible for 40% of Africa's recorded eruptions Lava flows, can me as fast as 90km/h 13km fissure was opened up, flowing to Goma and lake Kivu Stratovolcano 20km from Goma (1,000,000) , just west of Rwanda $480 GDP Per Capita Home to The Great African War from 98 to 03 Stratovolcano

Answer 37

Lava flows destroyed over 1/3 of Goma; Water, power and medical facilities destroyed including 3 health centres and 1 hospital Part of the airport was covered 147 Died Sulphurous lava contaminated Lake Kivu Medical attention for those effected by smoke and fumes 14 villages destroyed completely

Answer 38

Accompanying earthquakes caused structural damage to buildings Medical attention for diseases spread by contaminated water Looting homes and a petrol station exploded during looting 220,000 fled to Rwanda to escape lave, making aid difficult 500,000 homeless

Answer 39

UN supplied enough food to feed 700,000 for a week | Full evacuation of Goma

Answer 40

Volcanologists monitor Lake Kivu after fears lava, would release large amounts of carbon dioxide and methane

Answer 41

The caldera is 2.5km wide Constructive plate – North American plate moving west and the Eurasian moving east 11Km ash plume – fine grained ash 150m Ice cap $47,000 GDP Per Capita Sparsely-population, very volcanic, and cold Strombolian

Answer 42

Agricultural land damaged, farms hit by ash fall Roads destroyed No deaths or injuries A small number of people had respiratory and irritation issues

Answer 43

10 million airline passenger stranded abroad with over 100,000 flights cancelled over 8 days Ash contaminated local water supplies, impacting livestock Kenya lost $3.5 million as loss in exports Train industry boosted Cost $2.6Bn to Europe Flooding from glacier melt Flooding up to a year later due the silting up of rivers

Answer 44

People asked to stay indoors because of ash in the air 700 evacuated from flooding Entirely domestic responses

Answer 45

Far more tests on what planes can cope with in terms of ash, very little was known about this at the time

Answer 46

``` Ground shaking education damage death + injury lahars/avalanches liquefaction power station damge panic fear and hunger ```

Answer 47

Fire due to broken Gas pipes/power lines Emergency services hindered Contaminated water = disease

Answer 48

Education suspended | Lost generation + poor economic development locally

Answer 49

Un-buried bodies lead to more disease Disability trauma Long-term illness

Answer 50

Death and injury Flooding Loss of farmland and prouction Disruption to natural drainage basin

Answer 51

Foundations subside = death and injury | Repairs are difficult and expensive

Answer 52

Power cuts hinder emergency services | Reconstruction is very expensive

Answer 53

disorder and looting | Restoration of trust in neighbours

Answer 54

Friction builds up stress in the lithosphere Once overcome they fracture along cracks called faults The breaking point is the focus (hypocentre) Epicentre = point of surface above the focus

Answer 55

Primary/Pressure waves are the fastest – high frequency-Push-travel through mantle and core Secondary/Shear waves are half as fast – high frequency- shake – travel through mantle but not core Surface Love waves – slowest – most damage – side to side Rayleigh waves – radiate in complicated low frequency rolling up and down motion

Answer 56

Richter scale = magnitude – logarithmic | Mercalli Scale = intensity of damage – observations

Answer 57

``` Micro quakes Bulging ground Electrical and magnetic changes within rocks Increased argon in soil Animal behaviour ```

Answer 58

Wave height is less than 1m but can be up to 25m at shore Wavelength 100-1000km 650-1000kmh Series of waves, first not always the biggest Time between each wave = 10-60 minutes On approaching the coast, the front will slow down allowing the rear to pile up

Answer 59

7.8 magnitude and 15km deep – shallow 265 aftershocks a month on, 7.3 magnitude in May, caused further devastation Maximum of Severe on the Mercalli scale Landlocked, extremely mountainous country One of the poorest countries in the world with under $700 GDP per capita Caused by a sudden thrust along the major fault line where the Indian Plate, is sub ducting underneath the Eurasian Plate

Answer 60

``` 9000 dead, 20,000 injured Thousands of houses destroyed Airport closed for a day Death in churches due to the time of impact and old buildings 700,000 houses destroyed 5000 schools destroyed, 16,000 damaged ```

Answer 61

Avalanche on Everest – killing 19 – bad for tourist industry Hundreds of thousands homeless Landslides and aftershock – 200 dead from may aftershock Trauma, many aftershock Survivors preyed upon by human traffickers involved in brothels Sleeping in the streets cold, too scared to go back inside Displacement of people

Answer 62

90% of Nepalese army sent the worst areas Rainfall, after shock and small airport run-way slowed things down, aid had to be over landed on poor roads from India Social Media, Drone footage and satellite imaging were used $350 million donated from the international community

Answer 63

Calls for more aid – estimated just 10% of relief came from overseas Re-building of building sensibly Calls to build wider run-ways

Answer 64

Very shallow- 5 km, 6.3 magnitude, 6 miles from Christchurch Occurred on a conservative plate margin where the Pacific Plate slid past the Australian Plate in the opposite direction. It was the aftershock from a larger earthquake in 2010 but the impacts were more severe $42,000 GDP per capita

Answer 65

181 killed, 2000, injured Hundreds of kilometres of water and sewage piper were damaged Over half of the city buildings were damaged Moderate amount of liquefaction An iceberg of 20 football fields broke off 80% without electricity

Answer 66

Businesses put out of action causing losses of income and jobs Schools sharing classrooms due to damage elsewhere Difficult to get around due to transport destroyed Trauma, due to aftershocks, injury and death Tourism loss because they couldn’t host rugby world cup matches

Answer 67

Chemical toiles provided for 30,000 International aid of around $7 million and aid workers 300 Australian police arrived Earthquake commission assessed all buildings to ensure they were safe

Answer 68

Red Cross provide grants to families with children under 5 years Water and sewage all restored fully by august Roads and housed cleared of silt from liquefaction, 80% clear by August

Answer 69

Rolling weights on roof to counter-act shock waves Panels of marble and glass flexibly anchored to steel structure Bird cage like interlocking steel frame Reinforced latticework foundations deep in bedrock Rubber shock absorbers

Answer 70

Earthquake proof buildings Education – everyone knows what to do – practice drills Every one has an emergency survival kit You cant buy a phone without overriding warning software Warnings seconds before impact are simultaneously across all media Large network of seismometers Prediction- micro quakes, bulging, electrical and magnetic changes with rocks, in creased argon gas content in soil and curious animal behaviours 10m sea wall to prevent the effect of a Tsunami

Answer 71

500,000 into refugee camps in just one region of Indonesia Economies like fishing, agriculture and tourism ruined 44% of one region of Indonesia lost their livelihoods £226m damage to the Thai fishing industry Water supplies contaminated Inequality increases

Answer 72

Relief efforts with more than 160 aid agencies | Foreign military troops

Answer 73

Second biggest earthquake in history – 9.3 240Km of the coast of Sumatra Cause – the release of stress along a 1000km thrust fault Indian plate moved downwards by 15m, forcing the ocean floor above the thrust fault 8 aftershocks followed Warning were slow - with nothing on the media in Thailand until an hour after the first wave

Answer 74

290,000 died, thousands missing Vegetation + top soil removed up to 800m in land Infrastructure destroyed Coastal settlements devastated

Answer 75

Reconstruction- still thousands in tents a year on Aid was delayed by rebel group Tamil tigers in Sri Lanka Underclasses ignored by the government A UN group set up a warning system but it relies on the countries own alerts – tourist areas with sirens, rural communities with radio warning More education on awareness with drills and plans Areas at more risk were mapped

Answer 76

9.0 – 10m waves 100km from Sendai 500 km segment of the North American Plate dragged down my sub ducting pacific plate, moving upwards 10m 10 waves 1km apart

Answer 77

Weaker buildings collapsed Flooded 500 square metres 25,000 dead or missing

Answer 78

500,000 homeless Some homes without water or electricity, petrol had to rationed 700 aftershock traumatised people Explosions and leaks at Fukushima nuclear plant panicked the whole world, with stock markets plummeting

Answer 79

``` Helicopter rescues on roofs 100,000 soldiers Many countries offered aid Fukushima exclusion zone No reports of looting ```

Answer 80

Level of sea defence increased Government borrowing even more increased, resulting in austerity and tensions Trauma, illness and disablement

Plate Tectonics Flashcards

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