EAPS 106 EXAM 2 QUESTIONS AND CORRECT ANSWERS || 100% PASS

EAPS 106 EXAM 2 QUESTIONS AND CORRECT ANSWERS Q.The process by which subduction zone earthquakes cause tsunamis - ANSWERS-The most common means of generating a tsunami is uplift of the seafloor from elastic rebound during a large subduction zone earthquake. Q.Whether strikeslip earthquakes can cause tsunamis - ANSWERS-They cannot: will not cause a change in the height of the seafloor, do not displace any water (no tsunami), exception: can cause underwater landslides. Q.How tsunami and windblown waves differ - ANSWERS-Windblown waves only move water at the surface, while tsunamis are started at the based of the water column (carry a much larger volume of water, longer wavelength, and travel further inland), can be the same height as tsunami waves, tsunami waves volume are much much larger than windblown, which makes them more dangerous Q.The characteristics of a tsunami waves in deep water compared to shallow water - ANSWERS-deep water: long wavelengths, low wave heights, and great speed / shallow water: reduced wavelength, increased height, slower speed Q.What a boat in the middle of the ocean will experience if a tsunami wave passes beneath - ANSWERS-would rise less than a meter over a period of 10s of minutes and thus not even know that a tsunami has passed underneath because the wave height in water is not very tall until it begins to hit the shore. Q.When water waves will typically break - ANSWERS-when the depth of the water is equal to the wave height (does not happen in deep water), one giant tsunami has multiple breakpoints *water moves out first for a few minutes and then reverses to come onto the shore. Q.Whether the San Andreas Fault has the ability to cause a large tsunami - ANSWERS-the San Andreas Fault is a strike slip fault and therefore cannot create a tsunami. Q.Why being a good swimmer is probably not going to save you from a tsunami - ANSWERS-the tsunami picks up loose debris, meaning you are more likely to get crushed before drowning. Q.Why inlets are particularly dangerous places during a tsunami - ANSWERS-Inlets (natural harbor) are particularly dangerous places because the incoming water becomes trapped and piles up since it has nowhere to go (usually due to high mountains/elevation that surround the area) Q.Whether Japan should have anticipated the wave heights of the 2011 tsunami - ANSWERS-yes they have 3 10+ meter high tsunamis in the past 400 years. Q.How we know about past tsunamis in Japan and along the Washington/Oregon coast - ANSWERS-tsunami stones in japan are placed along the farthest place past tsunamis hit, along the pacific northwestern coast, sand deposits show the history of tsunamis in the area. Q.About how many people have been killed by tsunamis in the past 1000 years. - ANSWERS-several hundred thousand. Q.What it might mean if you feel shaking near the shore in terms of tsunami potential - ANSWERS-if the shaking is significant, there was likely a subduction zone earthquake several hundred kilometers out, then you have about 20 to 40 minutes before tsunami hits, so head to higher ground. Q.Why the sea level sometimes drops before a tsunami arrives - ANSWERS-when the tide goes out very fast and very far (over the span of 10/20 minutes), you have 5/10 minutes to get to higher group before a tsunami hits, trough created by the subduction zone pulls the water out and then the water crests and comes in. Q.Why it is dangerous to return to the shore after a tsunami wave - ANSWERS-tsunami waves are not just a single wave, usually 3 to 10 waves over a span of several hours, often the second or third wave is largest. Q.What a tsunami seawall is - ANSWERS-walls built along the shoreline to keep tsunami waters from reaching inland, however Japan's seawalls were 4/6 meters high; it was not prepared for the 10+ meter waves. Q.How long it takes a tsunami wave to cross the Pacific Ocean - ANSWERS-almost a day. Q.The reasons why so many people died around the Indian ocean due to the 2004 tsunami - ANSWERS-a lack of theses three things are reasons why so many people died and how it could have been prevented, education about tsunamis, an early warning system to detect tsunamis, a system to notify the public if a tsunami is suspected. Q.How the DART tsunami early warning system works - ANSWERS-Deep Ocean Assessment and Reporting of Tsunamis Early Warning System: a water pressure detector sits on the ocean floor, measurement are sent by acoustic signal to a buoy on the surface and the buoy send the signal further to a satellite and the signal is then sent to early warning stations inland, can send out tsunami warnings in a little as 15 minutes after an earthquake including path and size measurements. Q.Which process has the potential to cause the largest tsunamis - ANSWERS-asteroid impacts, through most common, earthquakes generally cause the smallest tsunami waves, volcanic eruptions and landslides can also create pretty big tsunamis.