The Little Bits
Richter Scale - is how scienists measure the strength of an earthquake.
Seismometer - is how they measure the earthquake.
Plate Boundaries - the areas in which the plates meet; where volcanoes and earthquakes take place.
Constructive Plate Boundaries - Moving away from each other; Mid Atlantic Rid.
Destructive Plate Boundaries - A oceanic plate moving under a continental plate; South American plate and the Nazca plate.
Conservative Plate Boundaries - Two plates siding next to one another; North American plate and the Pacific plate; San Francisco earthquake.
Collision Plate Boundaries - The two plates hitting one another; Himalayas; Indo Australian Plate.
Case Study: Kobe, Japan - Earthquake in MEDC
Place - Kobe, Japan
Date - 17th January 1995
Time - 5:46am
Dead - 5,500
Injured - 40,000
Homeless - 230,000
Damage Cost - £56 million
Size - 7.2
Margin - Destructive
Case Study: Gurjarat, India - Earthquake in LEDC
Place - Gurjarat, India
Date - 26th January 2001
Time - 8.50am
Dead - 30,000
Injured - ?
Homeless - Over a million
Damage Cost - Huge
Size - 7.9
Margin - Collison
Can You Predict an Earthquake?
The Three P's - Predict, Protect, Prepare
Predict - You cannot predict exactly when an earthquake is going to hit, but you can predict where abouts the earthquake may happen. There are some signs that can show however when an earthquake might hit -
- Observing unusual animal and fish behaviour.
- Plotting earthquakes when they happen so you know the average time between each earthquake in one area.
- Finding the 'gaps' on where earthquakes haven't hit on the plate margins.
Protect - You can protect the most vunerable areas that could be hit by an earthquake. Buildings are built on shock absorbers to take to shock of the earth tremors and have a computer controlled weight on top of the buildings to try and reduce the buildings movement.
Prepare - The places need plate margins that could be hit by an earthquake have plans and carry out regular practices. Emergency services members are trained to deal with the aftermarth and they organise emergency supplies of water, food and power in advance of the earthquake.
Case Study: Pinatubo - Volcano in LEDC
Name - Mount Pinatubo
Date - 9th June 1991
Cause - The Phillippines Plate moving under the Eurasion Plate [Destructive Margin]
What Happened - Ash and dust was ejected out of the volcano causing a pyroclastic flow and about 50cm of ash landed on the surrounding land. Ash was shot up 30km into the atmosphere.
Immediate Effects - 7th June: Americans evacuated all 15,000 personnal in the nearby airbases. The weight of the ash from the eruption made buildings collapse, including the local hospital. Power, water and roads were all damaged or containminated.
Long Term Effects - The ash fell on cropswhich stopped the growth of the crops and made it difficult to grow new crops. Animals died of stravation or diseaseor from drinking the containminated water. Villagers were forced to move to the cities for shetler and food. Disease spreed. The heavy rains brought lahars. However the erpution delayed global warming for several years.
Flooding: Mississippi, St Louis - MEDC
Where: St Louis, Mississippi River
- Heavy rain in April casues the soil saturated the soil.
- Thunderstorms in June causes flash flooding, which carried on into July which gave record rainfall.
- The 16m levees protecting the town collapsed and the river spread over the flood plains.
- The INFRASTUCTURE was damaged, the surrounding cities were also flooded and farmer's crops lost.
- Threat of disease spreading, houses and buildings ruined and massive insurance claims.
Flood Reductions in Place: Strengthing Levees, Dams, Straightening the river course to make it shorter, Afforestation and Diversionary Spillways.
Coastal Movement and Results
Spit: Hurst Castle Spit
Tombolo: Isle of Portland and Chesil Beach
Bar: Slapton Sands
Longshore Drift: UP THE BEACH - swash: DOWN THE BEACH - backwash: this is stopped by groynes and help one part of the coast but can effect another example - Barton On Sea & Bournemouth
Soft Rock - Chalk
Hard Rock - Limestone
Cliff, Headlands and Bays - Old Harry Rocks
Coastal Protection - Lincolnshire Coast:
- Sea Wall - Recurved Wall
- Rip - Rap
- Beach Rebuilding - Beach Replenishment
Case Study - Calstock
- Water Mill
- Water Power
- Wind Power - Turbines
- Solar Energy from a South facing slope
- Using local wood - coppicing