indian ocean tsunami 2004-karan gupta 07617, vikas singh 07612,
TRANSCRIPT
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
1/68
Indian Ocean
Tsunami of 2004Submitted By :
07612 - Vikas Singh
07617 - Karan Gupta
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
2/68
The Tsunami
Also called seismic sea wave
Generated by an undersea geologic event, such as a
great earthquake, volcanic explosion, or underwaterlandslide
Tsunami in Japanese means harbor wave
Tsunamis are not tidal waves
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
3/68
Subduction Zone Earthquake
Oceanic crust collides with continental crust andis forced downward
Compression forces build until rock fracturesand an earthquake occurs
Graphic Strahler/Wiley 2005
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
4/68
Generation of the Tsunami
During the earthquake, the seafloor movesupward, creating a water wave that spreads
outward.Graphic Gerard Fryer 2003
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
5/68
Undersea Landslideor Slump
Body of sediment slumpsdownward along acontinental shelf
Can be triggered by anearthquake
Water drops at head ofslump, rises at toe to
create a wave Wave moves outward as
a tsunami
Graphic Gerard Fryer 2003
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
6/68
Volcanic Explosion
The explosive eruption of Krakatau in August1883 created a tsunami that claimed more than36,000 lives
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
7/68
The Tsunami Wave
The tsunami wave has a wavelength of 100200 kmwith a deep water height of 1 m or less
Travels as fast as 200 m/s (440 mi/hr) in open ocean
As it approaches the shore, it slows, steepens, andrises in height
Deep ocean
Shoaling
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
8/68
The Wave Keeps Coming
The wave acts like a temporary rise in sea level,
pushing water far inland before it retreats
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
9/68
Indian Ocean Tsunami ofDecember 26, 2004
Caused by 9.0 earthquake beneath Java Trench,west of Sumatra, Indonesia
Fourth largest earthquake since 1900
1000 km of fault ruptured and sea floor movedupward by about 5 m (16 ft)
Sumatra
Java Trench
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
10/68
Earth's outer shell made up of ~15 major rigid plates ~ 100 km thick
Plates move relative to each other at speeds of a few cm/ yr (about
the speed at which fingernails grow)
Plates are rigid in the sense that little (ideally no) deformation occurs
within them,
Most (ideally all) deformation occurs at their boundaries, giving rise to
earthquakes, mountain building, volcanism, and other spectacular
phenomena.
Style of boundary and intraplate deformation depends on direction &rate of motion, together with thermo-mechanical structure
BASIC CONCEPTS: RIGID PLATES
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
11/68
BASICCONCEPTS:
THERMAL
EVOLUTION OFOCEANIC
LITHOSPHERE
Warm mantle material upwells at spreading centers and then cools
Because rock strength decreases with temperature, cooling material
forms strong plates of lithosphere
Cooling oceanic lithosphere moves away from the ridges, eventuallyreaches subduction zones and descends in downgoing slabs back into
the mantle, reheating as it goes
Lithosphere is cold outer boundary layer of thermal convection system
involving mantle and core that removes heat from Earth's interior,
controlling its evolution
Stein &Wysession2003
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
12/68
Gordon & Stein, 1992
INDIAN PLATE MOVES NORTHCOLLIDING WITH EURASIA
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
13/68
COMPLEX
PLATEBOUNDARYZONE IN
SOUTHEASTASIA
Northward motion ofIndia deforms all of
the region
Many small plates
(microplates) andblocks
Molnar & Tapponier, 1977
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
14/68
India subductsbeneath Burma
microplateat about 50 mm/yr
Earthquakes occurat plate interface
along the Sumatraarc (Sunda trench)
These are
spectacular &destructive resultsof many years of
accumulated motion
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
15/68
INTERSEISMIC:
India subducts beneathBurma microplate
at about 50 mm/yr(precise rate hard toinfer given complexgeometry)
Fault interface is locked
EARTHQUAKE(COSEISMIC):
Fault interface slips,overriding plate
rebounds, releasingaccumulated motion
HOW OFTEN:
Fault slipped ~ 10 m = 10000 mm / 50 mm/yr
10000 mm / 50 mm/yr = 200 yrLonger if some slip is aseismic
Faults arent exactly periodic for reasons we dont understand
Stein & Wysession, 2003
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
16/68
MODELINGSEISMOGRAMSshows how slip varied
on fault planeMaximum slip area~400 km long
Maximum slip ~ 20 mStein & Wysession
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
17/68
TWO VIEWS OF THE PART OF THE SUMATRASUBDUCTION ZONE THAT SLIPPED
Seismogram analysis showsmost slip in southern 400 km
Aftershocks show slipextended almost 1200 km
C. Ji
ERI
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
18/68
Earthquakes rupture a patchalong fault's surface.
Generally speaking, the
larger the rupture patch, thelarger the earthquakemagnitude.
Initial estimates from theaftershock distribution showthe magnitude 9.3 Sumatra-Andaman Islands Earthquakeruptured a patch of faultroughly the size of California
For comparison, a magnitude5 earthquake would rupture
a patch roughly the size ofNew York City's Central Park.
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
19/68
NORMAL MODES(ULTRA-LONG
PERIOD WAVES)SHOW SEISMICMOMENT 3 TIMESTHAT INFERREDFROM SURFACE
WAVESIMPLIES SLIP ONAREA 3 TIMESLARGER
Entire 1200-kmlong aftershockzone likely slipped
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
20/68
0S2 YIELDS SEISMICMOMENT Mo =
1 x 1030 dyn-cm
2.5 TIMES BIGGER THANINFERRED FROM 300-sSURFACE WAVES
CORRESPONDING MOMENTMAGNITUDE Mw IS 9.3,COMPARED TO 9.0 FROMSURFACE WAVES
Comparison of fault areas,moments, magnitudes,amount of slip shows this wasa gigantic earthquake
the big one
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
21/68
IF ENTIRE ZONESLIPPED, STRAINBUILT UP HASBEEN RELEASED,LEAVING LITTLEDANGER OFCOMPARABLE
TSUNAMI
Risk of local tsunamifrom large aftershocks
or oceanwide tsunamifrom boundarysegments to southremains
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
22/68
EARTHQUAKE MAGNITUDE9.3
One of the largest earthquakes since seismometer
invented ~ 1900
Stein & Wysession afterIRIS
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
23/68
SUCH GREATEARTHQUAKES
ARE RARE
Stein & Wysession,
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
24/68
SOME MAJOR DAMAGE DONE BY EARTHQUAKE SHAKING ITSELF,BUT STRONG GROUND MOTION DECAYS RAPIDLY WITH DISTANCE
0.2 g
Stein & Wysession,2003
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
25/68
0.2 g
Damage
onset for
modern
buildings
DAMAGE DEPENDS ON BUILDING TYPERESISTANT CONSTRUCTION REDUCES EARTHQUAKE RISKS
Earthquakes don't kill people; buildings kill"
Coburn &Spence 1992
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
26/68
TSUNAMI - water wave generated by earthquake
NY Times
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
27/68
TSUNAMI GENERATED ALONG FAULT, WHERE SEAFLOOR DISPLACED, AND SPREADS OUTWARD
http://staff.aist.go.jp/kenji.satake/animation.gif
Red - up motion, blue downHyndeman and Wang, 1993
Qui
Ti
TI
Z
i
i
ure.
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
28/68
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
29/68
WAVE PATH GIVEN BY SNELLS LAW
Going from material with speed v1 to speed v2
Angle of incidence I changes by
sin i1 / v1 = sin i2 / v2
SLOW
FAST
Tsunami wave bends as water depth & thus speed
Stein & Wysession
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
30/68
TRACE RAYPATHSUSINGSNELLS LAW
RAYS BENDAS WATERDEPTHCHANGES
FIND WHENWAVESARRIVE ATDIFFERENTPLACES
DENSITY OFWAVESSHOWSFOCUSING &DEFOCUSING
Woods & Okal, 1987
1 hour
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
31/68
NOAA
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
32/68
IN DEEP OCEAN tsunami has long wavelength, travels fast,small amplitude - doesnt affect ships
AS IT APPROACHES SHORE, it slows. Since energy is
conserved, amplitude builds up - very damaging
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
33/68
Because seismic waves travel muchfaster (km/s) than tsunamis, rapidanalysis of seismograms can identifyearthquakes likely to cause majortsunamis and predict when waves
will arrive
TSUNAMI WARNING
Deep ocean buoys can measurewave heights, verify tsunamiand reduce false alarms
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
34/68
HOWEVER, HARD TO PREDICT EARTHQUAKESrecurrence is highly variable
M>7 mean 132 yr W 105 yr
Estimated probability in 30 yrs 7-
Sieh et al.,1989Extend earthquake history
with geologic records -
paleoseismology
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
35/68
EARTHQUAKE RECURRENCEAT SUBDUCTION ZONES IS
COM PLICATED
In many subduction zones, thrustearthquakes have patterns inspace and time. Largeearthquakes occurred in theNankai trough area of Japanapproximately every 125 years
since 1498 with similar fault areas
In some cases entire regionseems to have slipped at once; inothers slip was divided intoseveral events over a few years.
Repeatability suggests that asegment that has not slipped forsome time is a gap due for anearthquake, but its hard to usethis concept well because of
variability
GAP?
NOTHING YET Ando, 1975
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
36/68
EARTHQUAKE PREDICTION?
Because little is known about the fundamental physics of faulting, manyattempts to predict earthquakes searched for precursors, observablebehavior that precedes earthquakes. To date, search has provedgenerally unsuccessful
In one hypothesis, all earthquakes start off as tiny earthquakes, whichhappen frequently, but only a few cascade via random failure processinto large earthquakes
This hypothesis draws on ideas from nonlinear dynamics or chaos theory,in which small perturbations can grow to have unpredictable largeconsequences. These ideas were posed in terms of the possibility thatthe flap of a butterfly's wings in Brazil might set off a tornado in Texas, orin general that minuscule disturbances do not affect the overall
frequency of storms but can modify when they occur
If so, there is nothing special about those tiny earthquakes that happentogrow into large ones, the interval between large earthquakes is highlyvariable and no observable precursors should occur before them. Thus
earthquake prediction is either impossible or nearly so.
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
37/68
PLATE TECTONICS ISDESTRUCTIVE TO HUMAN
SOCIETY
Mt SaintHelens1980 eruption
USGS
1989LomaPrietaearthquake
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
38/68
Plate boundary volcanism producesatmospheric gases (carbon dioxideCO2 ; water H2O) needed to support
life and keep planet warm enoughfor life ("greenhouse" )
May explain howlife evolved onearth (at midocean ridge hotsprings)
Plate tectonics raises continentsabove sea level
Plate tectonics produces mineralresources including fossil fuels
BUT PLATE TECTONICSIS ALSO CRUCIAL FOR
HUMAN LIFE
Press & Siever
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
39/68
CIVILIZATIONEXISTS BY
GEOLOGICALCONSENT
The same geologicprocesses that make our
planet habitable also make
it dangerous
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
40/68
Banda Aceh, Sumatra, Indonesia
Courtesy of DigitalGlobe June 23, 2004
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
41/68
Courtesy of DigitalGlobe
Banda Aceh, Sumatra, Indonesia
Dec 28, 2004
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
42/68
Kalutara Beach, Sri Lanka
Courtesy of DigitalGlobe Jan 1, 2004
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
43/68
Kalutara Beach, Sri Lanka
Courtesy of DigitalGlobe Dec 26, 2004
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
44/68
Kalutara Beach, Sri Lanka
Courtesy of DigitalGlobe Dec 26, 2004
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
45/68
Kalutara Beach, Sri Lanka
Courtesy of DigitalGlobe Dec 26, 2004
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
46/68
The Tsunamis Toll
Deaths: >210,000 Indonesia: 166,000
Thailand: 5,000
Sri Lanka: 30,000
India: 10,000 Damage: >$7 billion
Indonesia: $4.4 billion
India: $1.5 billion
Sri Lanka: $900 million Aid Donations: >$6.5 billion
Government pledges: $5.3 billion
Private donors: $12 billion
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
47/68
Southeast Asia Tsunami 2004
The worst tsunami in recorded history wascreated at 7:58 am on December 26, 2004
Magnitude 9.3 (second strongest earthquakeever recorded on a seismograph)
Lasted 10 minutes (longest lasting earthquakein history)
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
48/68
Southeast Asia Tsunami 2004
229,866 confirmed dead, which includes42,883 missing and never accounted for
More than $7 billion dollars damage
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
49/68
Southeast Asia Tsunami 2004
This earthquake was unusually large ingeographical extent
An estimated ~1,600 km (~1,000 mi) of fault lineslipped up to 15 m (50 ft) along the subduction
zone where geologist believed that the Indo-Australian plate dives under the Eurasian plate
However, researchinto this tsunamilead to thediscovery of theBurma microplate
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
50/68
Southeast Asia Tsunami 2004
Scientist now understand that the very largeIndia and Australian plates are being subductedunder the very small Burma microplate
The massivelybigger Indiaand Australianplates easilyshove the
smaller Burmamicroplatearound
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
51/68
Southeast Asia Tsunami 2004
Seismographic data revealed that the first phaseinvolved a rupture about 400 kilometers (250 miles)long and 100 kilometers (60 miles) wide, located30 kilometers (19 miles) beneath the sea bed,which is the longest rupture ever known to have
been caused by an earthquake
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
52/68
Southeast Asia Tsunami 2004
The rupture proceeded at a speed of about10,000 km/h (6,300 mph), beginning off the coastof Aceh and proceeding north-westerly over aperiod of about 100 seconds
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
53/68
Southeast Asia Tsunami 2004
Then a pause of about 100 seconds took placebefore the rupture continued northwardstowards the Andaman and Nicobar Islands
There was a vertical change along the rupture
that ranged from a few meters up to 50 meters
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
54/68
Southeast Asia Tsunami 2004
The sea bed isestimated to haverisen by severalmeters, displacingan estimated30 cubic kilometers(7 cubic miles) ofocean water and
triggeringdevastating tsunamiwaves
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
55/68
Southeast Asia Tsunami 2004
The tsunami waves did not originate from apoint source, but rather radiated outwardsalong the entire 1,600 kilometer (1,000 mile)length of the rupture
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
56/68
Southeast Asia Tsunami 2004
The common perception is that the tsunami wasjust one great wave that swept in from the sea
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
57/68
Southeast Asia Tsunami 2004
Actually, there were four tsunami waves thatcame ashore over a 90 minute time period
The resultingtsunamis
devastated theshores ofIndonesia, SriLanka, India,Thailand and othercountries withwaves as high as30 meters(100 feet)
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
58/68
Southeast Asia Tsunami 2004
Second tsunami wave starting toretreat at Kata Noi Beach, Thailand,10:17 am
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
59/68
Southeast Asia Tsunami 2004
Receding waters after the secondtsunami at 10:20 am
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
60/68
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
61/68
Southeast Asia Tsunami 2004
3rd tsunami wave arriving at 11:00am
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
62/68
Southeast Asia Tsunami 2004
4th tsunami wave just arriving at 11:22 am
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
63/68
Southeast Asia Tsunami 2004
These tsunamis caused serious damage and deathsas far as the east coast of Africa, with the farthestrecorded deaths due to the tsunami occurring inStruisbaai , South Africa, 8,000 kilometers(5,000 miles) away from the epicenter, where a
1.5 meter (5 foot) wave surged on shore during hightide about 12 hours after the earthquake
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
64/68
Southeast Asia Tsunami 2004
In addition to the staggering death toll, thedamage to cities and villages was estimatedto be seven billion dollars
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
65/68
Southeast Asia Tsunami 2004
TheU
S military provided the first foreign aid, butit took a week before help reached all of thestricken
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
66/68
Southeast Asia Tsunami 2004
A plot showing all of theaftershocks of magnitude4.0 and greater thatoccurred over a 15 dayperiod betweenDecember 26, 2004 and
January 10, 2005
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
67/68
Southeast Asia Tsunami 2004
The tsunami-lashed Andaman and Nicobar Islandssuffered 9,500 aftershocks between December 26and February 19
-
8/7/2019 Indian Ocean Tsunami 2004-Karan Gupta 07617, Vikas Singh 07612,
68/68
Southeast Asia Tsunami 2004
Meanwhile, thetectonic platesremain extremelyactive in Southeast
Asia
There have beenmany majorearthquakes in the
past and manymore will occur inthe future