Hazardous Earth 1

• Where are Cratons found?

  In the centre of continents typically South Africa and Brazil
• What is continental crust made of?

  Granite mostly
• The core is the _______ part of the Earth?

  Hottest
• what does ductile mean?

  movable or soft
• which is denser, oceanic or continental crust?

  oceanic
• what is the layer below the asthenosphere called?


  the mesosphere
• how thick is the asthenosphere?

  100-350 km thick
• Continental crust is thick and floats ____?

  high
• What are hazards?

  where physical and human systems meet, they are extreme events such as earthquakes and volcanic eruptions
• What is oceanic crust also known as ?

  mid oceanic ridges where magma shoots up, hardens and forms new rock. Oceanic crust is always forming
• the crust can either be the land we ____ on or the land under the ___?

  walk, sea
• the curst is solid and ____?

  thin
• is oceanic crust subductable?

  yes it is easily subductable and is constantly sinking
• When the crust is fused to the top layer of the mantle, we call this the what?

  the Lithosphere
• is continental crust young or old?

  old, 0-4000 Ma
• the asthenosphere is hot and the _____ is slow moving and _____?

  magma, ductile
• What is a Craton?

  pieces of rock that are still here from when the Earth was formed, they are 4 billion years old
• What does intrusive mean? 

  Buried underneath or within other layers of rock
• what are the three types of mitigation?

  mitigation for vulnerability (before), mitigation of the event, mitigation for loss(after)
• what does MMS stand for ?

  Moment magnitude scale
• what are the last waves to reach a building during an earthquake?

  surface waves
• Give one reason why the MMS is better than the richter scale?

  accurate for all EQ sizes, it is globally applicable, it is a consistent energy measurment
• what are two other ways to say subduction?

  tectonic shortening / rebound
• how many km cubed are emitted from a volcano?

  1000 km cubed
• Tsunamis (____ ocean) travel up to ____ km/h, but slow down to __ to __ km/h near shore?


  deep, 800, 20, 50
• pyroclastic flows flow at __ to ___km/h, these are the ___ ___ ____?

  80 , 700, fastest volcanic phenomena
• pyroclastic flows are composed of ____ gas, ash and ___, they are almost ____ to escape if ____?

  hot, rock, impossible, nearby
• lahars travel at __ to ___km/h , depending on ____ and ___ ____?

  10, 100, slope, water content
• Lava usually flows at less than __ km/h, though very __ __ ___ can reach __km/h, most people can ___ lava however?

  10, fluid basaltic lava, 30, outrun
• what is tephra?


  fragments of volcanic material ejected during an eruption
• what building has a 660 ton pendulum to establish its aseismic security?

  Taipei 101
• What US building was retrofitted 100 years after construction with 280 base isolators?

  State Capitol Utah
• which building in Japan has steel tubes and a central flexible steel column that can vibrate independently to minimise the whole building shaking?

  Sky tree Tokyo
• How many stratovolcanoes are there on the planer?

  734
• how many shield volcanoes are there on the planet?

  171
• where are 75% of all stratovolcanoes found?

  Ring of Fire or where destructive boundaries occur at the edge of the subducting pacific ocean plate
• what is a jokulhlaup?

  a flood, caused by melting of ice/ glaciers after a volcanic eruption
• which colourless and odourless gas is potentially measurable as it is released when stress creates microfractures and pathways for the gas to escape?

  Radon
• avalanches and rock fall are able to ?

  block rivers, causing a dam in the river and causing it to flood creating a quake lake
• is it possible to predict an EQ?


  no