exam 2 EAPS
The indicators that a tsunami wave may be approaching and how much time you have to escape
Significant seismic shaking near the shore: - 20-40 minutes before a tsunami hits: Head to high ground
About how many volcano-related deaths have occurred in the past 500 years
250,000
How the DART tsunami early warning system works
The DART early warning system can send out tsunami warnings in as little as 15 minutes after an earthquake, including path and size estimates. • The key is the pressure sensor on the seafloor.
Why the Krakatoa was historically so significant
The Scream by Edvard Munch was influenced by sunsets in Norway
What caused the largest tsunami run-up (the height water reached on land) ever recorded
a tsunami generated by an avalanche into Lituya Bay, Alaska
The various causes of tsunamis, which are have the potential to be the biggest, and which regions of the US they endanger
distant earthquakes(biggest), local earthquakes, landslides, volcanic eruptions, asteroid impacts, underwater landslides in the atlantic: east coast
How we know Yellowstone is a hotspot
When the plume head hit the surface it erupted a giant flood basalt followed by a hotspot track to its present location beneath Yellowstone
About how many total people have been killed by historic tsunamis
several hundred thousand people
How shield volcanoes form
their lava is very low viscosity that leads to broad topography
The history, evidence for, and consequences of large, explosive eruptions at Yellowstone
three calderas, indicating three very large eruptions,Comparison of ashfalls from Mt. St. Helens (VEI 5) and yellowstone's past 3 eruptions, seismic network and seismicity. inferred subsurface structure. Ash fallout and global cooling
The dangers tsunamis pose when they come on shore
tremendous amount of debris the water picks up and carries inland, People caught in tsunamis generally do not drown, they are crushed.
How we know about past tsunamis
tsunami stones, past people who lived in area
How the Hawaiian Islands generate tsunami
underwater landslides
The basic characteristics of the various volcanic hazards and which ones cause the most and least fatalities
unknown, lightening, seismicity, flood, debris avalange, gas, lava, tsunami, indirect(famine), direct and indirect mudflow, pyroplastic flow/ surge, tephra Most: pyoplastic flow least: lava
How subduction zone earthquakes cause tsunamis
uplift of the seafloor from elastic rebound during a large subduction zone earthquake
What causes explosive eruptions?
viscosity of the magma
how cinder cones form
when tephra (cooled lava fragments) are thrown out of a volcanic vent
What Pliny the Younger was famous for
wrote the description of the volcanic eruption in Pompeii. wrote down the unbelievable account of the eruption of Mount Vesuvius and the destruction of Pompeii.
Why the destruction of Pompeii in 79 AD is so interesting
• 2,000 people were killed. • Pompeii was buried under more than 30 feet of ash and lost from history for 1500 years, but was preserved by the ash and dug out. • The ash preserved the forms of the dead.
Know the common precursors to a volcanic eruption and whether volcanic eruptions are predictable
• Earthquake frequency increases • Harmonic Tremors • Gas release (sulfur or carbon dioxide) or shuts off • Rapid ground deformation (uplift or tilt) • Surface temperature increase . Yes, but such predictions are never straightforward
Why so many people died around the Indian ocean due to the 2004 tsunami
• Education about tsunamis • An early warning system to detect tsunamis • A system to notify the public if a tsunami is suspected
Understand the global consequences of large explosive volcanic eruptions
• Explosive eruptions emit large amounts of ash and SO2. • SO2 reacts with oxygen and water vapor to create sulfuric acid droplets. • The ash and sulfuric acid droplets block sunlight, causing global cooling (sulfuric acid droplets actually stay aloft longer).
How the characteristics of a tsunami wave change as a function of water depth
• Out at sea (in deep water) tsunami waves have long wavelengths (distance from crest to crest), low wave heights, and great speed (jetliner speed). • As waves approach shore they slow down (car driving through campus speed), which causes the back of the waves to catch up the front, reducing wavelength, but increasing wave height.
Which types of earthquake generally cause tsunami
greater than 6.7 magnitude , subduction zone earthquake
The four main types of eruptions and their relative sizes
hawaiian(2 km or 6500 ft), strombolian(10 mk or 38800), vulcanian(20 km or 65600), plinian(55 km or 180400 ft)
Know some basic facts about the Hawaiian Islands (how the formed, whether they are tall)
hot spot tracks, shield volcanoes and tallest mountain measured on earth from seafloor to its top
What viscosity is a measure of
how easily a fluid flows
How and where hot rocks melt
increasing temperature, decreasing pressure and adding water to the mineralogy
How calderas form
is a large circular depression formed when the surface collapses into an emptied magma chamber
ring of fire
A circle of volcanoes surrounding the Pacific Ocean. Subduction zone volcanism occurs everywhere plates are subducted, causing a "Ring of Fire" around the Pacific Ocean.
the factors that influence whether a volcano will explode
Amount of magma, amount of dissolved gas and viscosity of magma
Understand the cause of hotspot volcanism and why it leads to a chain of volcanoes
Heating of the base of the mantle by the core. The Hawaiian Islands are a hot spot track where the islands get progressively older to the northwest as the Pacific Plate continues to move over the hot spot.
The indicators that a tsunami wave may be approaching and how much time you have to escape
The tide appears to go out very fast and very far: - 5-10 minutes before the tsunami hits: Get to high ground faster
The indicators that a tsunami wave may be approaching and how much time you have to escape
Tsunami consist of 3-10 waves, and often the 2nd or 3rd wave is the largest — don't go back to the shore until given the all clear or at least many hours have passed
When water waves will generally break
Tsunami waves (like all water waves) break when the wave height is about equal to the water depth
How tsunami and wind-blown waves differ
Tsunami waves can have similar heights to large wind blown waves, but carry a much larger volume of water, have a much longer wavelength (distance from crest to crest), and travel much further inland.
why the Toba eruption was historically so significant
lead to global cooling that almost wiped out humanity.
Understand the global consequences of giant flood basalts
mass extinctions bc of Large amounts of greenhouse gases led to global warming and acid rain
The settings where the different types of volcanism are found
mid- ocean ridges, subduction zones, and hot spots.
how stratovolcanoes form
midsized volcanoes that form due to alternating layers of pyroclastic flows (explosive) and lava flows (effusive).
why the Tambora eruption was historically so significant
monster creator, In the cold Tambora summer of 1816, while together on holiday in Switzerland, Mary Shelley came up with Frankenstein and Lord Byron came up with Dracula
Understand what the Volcano Explosivity Index (VEI) scale is a measure of
numeric scale that measures the relative explosive of historic eruptions. volume of ash and other rock
How the extent and activity of the magma chamber under Yellowstone is explored
seismic network and seismicity