NOVA: Wave That Shook The World
1: What is a tsunami?
Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea.
2: When did this tsunami happen? (date)
December 26, 2004
3: How many people died, in how many countries?
225,000 people died in 11 countries.
4: What is the name of the warning center in Hawaii?
The warning center name is Pacific Tsunami
5: An area where one tectonic plate is pushing under another is called?
Subduction
6: What magnitude was this earthquake? What is a seismograph?
Some geologists estimate that the earthquake that caused the disaster measured 9.3 on the Richter scale
Each unit in magnitude is a factor of 30 of radiant energy of an earthquake.
Earthquake scientists get paged when an earthquake of a factor of 9 or larger
occurs.
7: How do tsunami sensor buoys work? Explain.
A tsunami buoy is a specialized buoy which is able to detect subtle changes in water pressure which could indicate an incoming tsunami.When a tsunami buoy detects a pressure pattern which could be a tsunami, it immediately sends information to the satellite, and the information is passed on to regional tsunami warning centers. These centers can also contact the buoy to request information, either to download general observations and data, or to address specific concerns after a seismic event which might trigger a tsunami.
How many warning sensors/buoys are there in the Pacific? In the Indian Ocean?
6
8: This earthquake was shallow. How many kilometers deep was it? 30
9: What is “tsunami initiation”? Explain.
A sudden offset changes the elevation of the ocean and initiates a water wave that travels outward from the region of sea-floor disruption.
11: How fast does the tsunami wave travel? Why is this different than a “surfer’s wave”?
500 to 1,000 km/h (310 to 620 mph)
12: What does a boat in the open ocean feel during a tsunami wave?
An earthquake is a natural tsunami warning; If you see the ocean receding unusually rapidly, that's a good sign that a tsunami may be on its way.
13: What warning sign often occurs at the beach during a tsunami? What is
Amplification?
Severe ground shaking from local earthquakes may cause tsunamis.As a tsunami approaches shorelines, water may recede from the coast, exposing the ocean floor, reefs and fish.Abnormal ocean activity, a wall of water, and an approaching tsunami create a loud "roaring" sound similar to that of a train or jet aircraft.If you experience any of these phenomena, don't wait for official evacuation orders.Immediately leave low-lying coastal areas and move to higher ground.
Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea.
2: When did this tsunami happen? (date)
December 26, 2004
3: How many people died, in how many countries?
225,000 people died in 11 countries.
4: What is the name of the warning center in Hawaii?
The warning center name is Pacific Tsunami
5: An area where one tectonic plate is pushing under another is called?
Subduction
6: What magnitude was this earthquake? What is a seismograph?
Some geologists estimate that the earthquake that caused the disaster measured 9.3 on the Richter scale
Each unit in magnitude is a factor of 30 of radiant energy of an earthquake.
Earthquake scientists get paged when an earthquake of a factor of 9 or larger
occurs.
7: How do tsunami sensor buoys work? Explain.
A tsunami buoy is a specialized buoy which is able to detect subtle changes in water pressure which could indicate an incoming tsunami.When a tsunami buoy detects a pressure pattern which could be a tsunami, it immediately sends information to the satellite, and the information is passed on to regional tsunami warning centers. These centers can also contact the buoy to request information, either to download general observations and data, or to address specific concerns after a seismic event which might trigger a tsunami.
How many warning sensors/buoys are there in the Pacific? In the Indian Ocean?
6
8: This earthquake was shallow. How many kilometers deep was it? 30
9: What is “tsunami initiation”? Explain.
A sudden offset changes the elevation of the ocean and initiates a water wave that travels outward from the region of sea-floor disruption.
11: How fast does the tsunami wave travel? Why is this different than a “surfer’s wave”?
500 to 1,000 km/h (310 to 620 mph)
12: What does a boat in the open ocean feel during a tsunami wave?
An earthquake is a natural tsunami warning; If you see the ocean receding unusually rapidly, that's a good sign that a tsunami may be on its way.
13: What warning sign often occurs at the beach during a tsunami? What is
Amplification?
Severe ground shaking from local earthquakes may cause tsunamis.As a tsunami approaches shorelines, water may recede from the coast, exposing the ocean floor, reefs and fish.Abnormal ocean activity, a wall of water, and an approaching tsunami create a loud "roaring" sound similar to that of a train or jet aircraft.If you experience any of these phenomena, don't wait for official evacuation orders.Immediately leave low-lying coastal areas and move to higher ground.
If the waves on the beach suddenly suck out and expose the ocean floor for a large
distance out, WHY should you not run out to check it out? What should you do
instead?If you are at the beach or near the ocean and you feel the earth shake, move immediately to higher ground.DO NOT wait for a tsunami warning to be announced.Stay away from rivers and streams that lead to the ocean as you would stay away from the beach and ocean if there is a tsunami.A tsunami from a local earthquake could strike some areas before a tsunami warning could be announced.
distance out, WHY should you not run out to check it out? What should you do
instead?If you are at the beach or near the ocean and you feel the earth shake, move immediately to higher ground.DO NOT wait for a tsunami warning to be announced.Stay away from rivers and streams that lead to the ocean as you would stay away from the beach and ocean if there is a tsunami.A tsunami from a local earthquake could strike some areas before a tsunami warning could be announced.
14: Is there usually only one wave in a tsunami? Is there a pattern to the waves? Explain.
A tsunami generally consists of a series of waves, often referred to as the tsunami wave train.The amount of time between successive waves, known as the wave period, is only a few minutes; in some instances, waves are over an hour apart.
15: Where is greater damage likely, on a gently sloping beach or a steeply sloping beach?
Explain why. gently sloping
16: True or false, you are safe as the tsunami wave is passing back out? False
17: How did the quake affect the earth’s day?
May have shortened the length of each Earth day and shifted its axis.But don't worry—you won't notice the difference.
18: What area of the United States is at risk for the same type of earthquake?Portions of all 50 states and the District of Columbia are vulnerable to earthquake hazards,
although risks vary greatly across the country and within individual states. Seismic hazards are
greatest in the western United States, particularly in California, Washington, Oregon, and Alaska
and Hawaii
19: What are the four causes of a tsunami?
Anything that rapidly displaces a large volume of water can cause a tsunami.Typically, tsunamis are caused by underwater earthquakes, but landslides, volcanic eruptions, calving icebergs, and (very rarely) meteorite impacts can also generate tsunamis.These types of events can cause large disturbances in the surface of the ocean, and when gravity pulls the water back down, the tsunami is born.
How many people on Earth are at risk of a tsunami?
20: What is happening in the Cascadia Subduction Zone? What could happen?
The Cascadia Subduction Zone is still active and will generate more major earthquakes in the future.
21: What is being done to help prepare for future tsunamis?
Disaster risk reduction as a political priority; Risk assessment and early warning systems; Education and public awareness; Mitigation and building codes; Preparedness for response
22: How many more buoys did the United States add to the Pacific Warning system?
What else is part of the Tsunami warning system?
39
A tsunami generally consists of a series of waves, often referred to as the tsunami wave train.The amount of time between successive waves, known as the wave period, is only a few minutes; in some instances, waves are over an hour apart.
15: Where is greater damage likely, on a gently sloping beach or a steeply sloping beach?
Explain why. gently sloping
16: True or false, you are safe as the tsunami wave is passing back out? False
17: How did the quake affect the earth’s day?
May have shortened the length of each Earth day and shifted its axis.But don't worry—you won't notice the difference.
18: What area of the United States is at risk for the same type of earthquake?Portions of all 50 states and the District of Columbia are vulnerable to earthquake hazards,
although risks vary greatly across the country and within individual states. Seismic hazards are
greatest in the western United States, particularly in California, Washington, Oregon, and Alaska
and Hawaii
19: What are the four causes of a tsunami?
Anything that rapidly displaces a large volume of water can cause a tsunami.Typically, tsunamis are caused by underwater earthquakes, but landslides, volcanic eruptions, calving icebergs, and (very rarely) meteorite impacts can also generate tsunamis.These types of events can cause large disturbances in the surface of the ocean, and when gravity pulls the water back down, the tsunami is born.
How many people on Earth are at risk of a tsunami?
20: What is happening in the Cascadia Subduction Zone? What could happen?
The Cascadia Subduction Zone is still active and will generate more major earthquakes in the future.
21: What is being done to help prepare for future tsunamis?
Disaster risk reduction as a political priority; Risk assessment and early warning systems; Education and public awareness; Mitigation and building codes; Preparedness for response
22: How many more buoys did the United States add to the Pacific Warning system?
What else is part of the Tsunami warning system?
39