TSUNAMIS

1
TSUNAMIS

• HARBOR WAVE

By Bijana Allen Mark Villalas
2
Main Points

• Characteristics of Tsunamis
• How are they caused?
• Human and Environmental Impacts
• Overview of Past Tsunamis
• Asian Tsunami of 2004
• Tsunami Detection/ Warning Alerts
• DART Warning System

3
What are Tsunamis?

• Japanese term meaning harbor wave
• Confused with tidal waves, but they have nothing
  to do with the tides
• A result of sudden vertical faulting in the
  ocean floor caused by earthquakes, volcanoes, and
  submarine landslides
• Most tsunamis are a byproduct of earthquakes

4
Characteristics of Tsunamis

• The speed of the tsunami is greater in deeper
  water. Waves are unnoticeable.
• - Speeds up to 700 Kilo/ Hr
• - Equivalent to an aircraft going 435
  Miles/ Hr.
• Speed decreases in shallow water, but the height
  of the waves increases dramatically. Up to 100
  miles high.
• Water leaves quickly from the shore before the
  tsunami hits.

5
Causes

• Sea floor abruptly deforms and vertically
  displaces the overlying water.
• Large vertical faulting occurs at plate
  boundaries.
• Subduction earthquakes are effective in creating
  tsunamis.
• When the Oceanic Plate is subducted beneath a
  Continental Plate, it brings down the lip of the
  Continental Plate with it. Eventually, too much
  stress is put on the lip and it snaps back,
  sending shockwaves through the Earths crust,
  causing a Undersea Earthquake. Resulting in a
  tsunami
• http//www.tsunami.noaa.gov/animations/tsunami_gen
  esis.avi

6
Human Environmental Impacts

• Destroying coral reefs in many countries across
  Asia including Indonesia, Sri Lanka, and
  Bangladesh making way for shrimp farms and other
  economic choices impacted them by eliminating the
  natural protection of the reefs.
• Many people were saved on the Surin Island chain
  of Thailands coast because the coral reefs acted
  like a buffer to take some of the impact of the
  tsunami
• The mangroves along with coastal sand dunes were
  viewed as obstacles during resort construction
  and therefore removed
• These natural barriers may have blocked some of
  the force of the tsunami. Subsequently the homes
  and resorts offered little resistance to the
  fierce tsunami
• Ecosystems such as forests, vegetation, coastal
  wetlands, rock formations, animals, plants, and
  groundwater sustained severe damage
• Concern for the polluted water supplies because
  of solid and liquid waste as well as industrial
  chemicals.
• The extent of the environmental impact will take
  years and significant resources to repair and
  restore damages.

7
Overview of Past Tsunamis
The Pacific Tsunami Warning Center created
Wikepedia.com
8
Asian Tsunami of 2004

• Before
  After
• (Aceh Province in Sumatra, Indonesia)

9
Tsunami Detection/ Warning Alerts

• Difficult because tsunamis speed is faster in
  deep water with a minimum height and a network of
  sensors is needed to detect it
• Its a bigger challenge to set up a communication
  infrastructure to issue warnings
• Pacific Ocean already has warning systems due to
  frequent earthquakes in the region.
• Indian Ocean on the other hand does not have any
  warning systems

10
Ache, Indonesia

• The Aftermath

11
DART Warning System

• Deep-ocean Assessment and Reporting of Tsunamis
  (DART)
• First one launched in the Indian Ocean on Dec. 1,
  2006 as a result of the devastating Asian Tsunami
  in 2004.
• The new system will provide the U.S. with nearly
  100 detection capability for its coastal
  regions, allowing response within minutes.
• It will also monitor throughout the entire
  Pacific and Caribbean basins, providing tsunami
  warning for regions bordering half of the worlds
  oceans.
• A total of 32 DART systems will be deployed all
  around the world by mid-2007

12
Recap of Main Points

• Characteristics of Tsunamis
• How are they caused?
• Human and Environmental Impacts
• Overview of Past Tsunamis
• Asian Tsunami of 2004
• Tsunami Detection/ Warning Alerts
• DART Warning System

13
Final Thought

• Although the Asian tsunami created a great
  tragedy too many people, it also did a lot to
  educate us globally, and to bring awareness to
  tsunamis and earthquakes in general. The
  devastation in these countries helped to unite
  the world together in an effort to provide relief
  to the affected people. Governments and
  individuals donated billions of dollars to
  rebuild and help the people of these countries in
  need. Similarly, the tragedy of the situation
  brought awareness to the need for a global alert
  system in order to minimize deaths associated
  with tsunamis.