1) Tsunamis are extremely large ocean waves caused by underwater disturbances like earthquakes, volcanic eruptions, or landslides. The 2004 Indian Ocean tsunami was caused by a 9.3 magnitude earthquake and killed over 230,000 people across several countries. 2) Major tsunamis throughout history include ones in 1896, 1946, 1958, 1960, 1964, 1976, and 1998 that caused significant loss of life. The most deadly was the 2004 Indian Ocean tsunami. 3) Tsunamis can have devastating environmental impacts by destroying infrastructure, habitats, and contaminating soil and water sources. They also spread diseases in their aftermath and have long-lasting effects on ecosystems. Warning systems use

1. Tsunami Occurrence
by
CHITTURI LAVANYA
Guided by
Asst. Professor M. Venkatesh

2. Tsunami Occurrence
TSUNAMI IS A JAPANESE WORD ‘TSU’ MEANS “HARBOUR” AND ‘NAMI’ MEANS “WAVE”. TSUNAMI IS DEFINES AS EXTREMELY LARGE
OCEAN WAVES TRIGGERED BY UNDER WAVES EARTHQUAKES, VOLCANIC OR LANDSLIDES. TSUNAMIS ARE SOMETIMES REFERRED TO
AS “TIDAL WAVES” BY THE GENERAL PUBLIC, WHICH IS A WRONG AS TSUNAMI ARE UNRELATED TO THE TIDES [1]
www.slideshare.net/soubamindrakumar/tsunami-88220119

3. History (1896 – 2004)
• June 15, 1896 (100 feet) at 8.2 magnitude earthquake in Japan and 27000 were died. [2]
• April 1, 1946 (130 feet) at 7.4 magnitude earthquake and 150 died in Hawaii. [2]
• July 9, 1958 (1720 feet) at 7.8 magnitude earthquake in Alaska and 2 were died. [2]
• May 22, 1960 (25 feet) at 9.5 magnitude earthquake in Chile. 1500 were died in Chile and Hawaii. [2]
• March 27, 1964 (67 feet) 9.2 magnitude earthquake in Alaska and 120 died in northern California. [2]
• August 23, 1976 (9 meters) 8.0 magnitude earthquake 8000 were died in southwest Philippines. [2]
• July 17, 1998 7.0 (49 feet) magnitude earthquake and 2200 were died in New Guinea. [2]
www.livescience.com/3731-tsunamis-history.html
Because of seismic and volcanic activity associated with tectonic plate tsunamis, occur most frequently in the Pacific Ocean. The oldest recorded
tsunami occurred in 479 BC.

4. 2004 Indian Tsunami
 The quake was named the Sumatra-Andaman earthquake, and the tsunami has become known as
the 2004 Indian Ocean Tsunami[3,4]
https://commons.wikimedia.org/wiki/File:Harta_Ocean_Indian_Quake.png
https://www.slideshare.net/soubamindrakumar/tsunami-88220119
 It was 7:58 a.m. when the tremendous quake struck beneath the Indian Ocean 160 miles west of Sumatra. Not only did it register at approximately a 9.3
magnitude (only the 1960 Chile earthquake measured higher at 9.5, though there may have been stronger tremors prior to the invention of
seismographic equipment) and last nearly 10 minutes, the quake moved a full 750 miles of underwater fault line earth up to 40 feet. The movement of
the earth—there is evidence that huge boulders weighing thousands of tons were pushed several miles along the ocean floor caused a massive
displacement of water. It is estimated that the resulting tsunami had two times the energy of all the bombs used during World War II and waves up to
15 meters shook Indonesia and killed an estimated 2,30,000 people.[3]

5. TSUNAMI AFFECTED AREAS
Pic source https://www.researchgate.net/figure/The-2004-tsunami-
affected-areas-source-wwwworldatlascom_fig1_310457889
Effected areas by 2004 Indian Ocean Tsunami through out the world [5]
Pic source https://www.mapsofindia.com/maps/tsunami-in-
india/tsunami-affected-area-india.html
Effected areas in India by 2004 Indian Tsunami[6]

6.  Seismicity, the worldwide or local distribution of earthquakes in space, time, and magnitude. More specially, it
refers to the measure of the frequency of earthquake in a region.
 The frequency range of seismic waves is large, from as high as the audible range (greater than 20 hertz) to as
low as the frequencies of the free oscillations of the whole Earth, with the gravest period being 54 minutes.
Attenuation of the waves in rock imposes high-frequency limits, and in small to moderate earthquakes the
dominant frequencies extend in surface waves from about 1 to 0.1 hertz.
 Very close to the seismic sources of great earthquakes, investigators have measured large wave amplitudes
with accelerations of the ground exceeding that of gravity (9.8 meters, or 32.2 feet, per second squared) at
high frequencies and ground displacements of 1 meter at low frequencies. [7]
1. Seismicity
Causes of Tsunami
https://ballotpedia.org/Seismicity

7.  Volcanic eruptions represent also impulsive disturbances, which can displace a great volume of water and generate
extremely destructive tsunami waves in the immediate source area.
 Although relatively infrequent, violent volcanic eruptions represent also impulsive disturbances, which can displace a
great volume of water and generate extremely destructive tsunami waves in the immediate source area. According to
this mechanism, waves may be generated by the sudden displacement of water caused by a volcanic explosion, by a
volcanos slope failure, or more likely by a phreatomagmatic explosion and collapse/engulfment of the volcanic
magmatic chambers. [8,9]
2. Volcanic Eruption
https://iotic.ioc-unesco.org/what-causes-tsunami/
https://www.google.com/search?q=volcanic+eruption+due+to+tsunami&rlz=1C1FKPE_enIN985IN985&sxsrf=ALiCzsYjAkRj_TzEBPD
avjBTjSR6fKkf8w:1652348953883&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiktMPD19n3AhUJHKYKHZYAB1AQ_AUoAXoECAE
QAw&biw=1536&bih=792&dpr=1.25#imgrc=n-XzliUoweKJuM

8. Less frequency, tsunami waves can be generated from displacement of water resulting from rock falls, ice falls and sudden submarine landslides or
slumps. A landslide that occurs along the coast can force large amounts of water into the sea, disturbing the water and generate a tsunami. Underwater
landslides can also result in tsunamis when the material loosened by the landslide moves violently, pushing the water in front of it. [10, 11, 12]
3. Icefall & Land slides
https://iotic.ioc-unesco.org/what-causes-tsunami/
https://ichef.bbci.co.uk/news/976/cpsprodpb/DFD7/production/_104930375_in
donesia_tsunami_explainer_640-nc.png
https://in.pinterest.com/pin/423408802452963161/

9. Effects of Tsunami
There are three factors of destruction from tsunamis, wave impact on structures, and erosion. Strong tsunami induced
Current lead to erosion of foundation and the collapse of bridges and seawalls. Flotation and drag force move the houses,
turnover railroad cars and ships. [13,14]
• Destruction
https://www.dw.com/en/climate-induced-sea-level-rise-to-worsen-tsunami-impacts/a-45730449
http://itic.ioc-
unesco.org/index.php?option=com_content&view=article&id=1205
&Itemid=2029#:~:text=There%20are%20three%20factors%20of,ho
uses%20and%20overturn%20railroad%20cars.

10. • Death
Tsunamis are giant waves that are produced when a large
volume of water is displaced in an ocean or large lake by
an earthquake, volcanic eruption, underwater landslide or
meteorite. Between 1998-2017, tsunamis caused more
than 250 000 deaths globally, including more than 227 000
deaths due to the Indian Ocean tsunami in 2004. [15]
https://www.who.int/health-topics/tsunamis#tab=tab_1
Some survivors of the tsunami that struck South Asia on 26 December 2004 are
experiencing a new peril mud and bacteria they inhaled as they were swept along
with the waves has led to a type of aspiration pneumonia called “tsunami lung.
Flooding and contamination of drinking water can cause diseases like Cholera,
Diarrhoea, Malaria, Chest infections, Dengue fever, Typhoid, Other infections.
Other diseases include hepatitis A, vaginal infections and diseases affecting
children. Workers handling corpses are also prone to diarrhoea - but also to
tuberculosis. [16]
• Diseases
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1310941/#:~:text=New%20concerns%20in%20devastati
on's%20wake,pneumonia%20called%20%E2%80%9Ctsunami%20lung.%E2%80%9D

11. Environmental Impacts
• Solid Waste, Disaster Debris, and Sewage
• Contamination of soil and water
• Loss of Infrastructure and Facilities
• Loss of Natural Ecosystems
• Impact to Biological Communities and Species [17]
• Tsunamis not only destroy human life, but have a devastating effect on insects, animals, plants, and natural resources. A tsunami changes the landscape. It
uproots trees and plants and destroys animal habitats such as nesting sites for birds. Land animals are killed by drowning and sea animals are killed by
pollution if dangerous chemicals are washed away into the sea, thus poisoning the marine life.
• The impact of a tsunami on the environment relates not only to the landscape and animal life, but also to the man-made aspects of the environment. Solid
waste and disaster debris are the most critical environmental problem faced by a tsunami-hit country. [18]
https://www.sms-tsunami-warning.com/pages/tsunami-effects#.Yn3_HuhBxEY
https://www.slideshare.net/soubamindrakumar/tsunami-88220119

12. WARNING TOWARDS TSUNAMI
 Early warnings come nearly animals as they sense danger and flee to higher grounds
 A tsunami warning system (TWS) is used to detect tsunamis in advance and issue the warnings to prevent loss of life and
damage to property. It is made up of two equally important components: a network of sensors to detect tsunamis and a
communications infrastructure to issue timely alarms to permit evacuation of the coastal areas. There are two distinct types
of tsunami warning systems: international and regional.[19]
https://en.wikipedia.org/wiki/Tsunami_warning_system

13. Remote sensing for Tsunami Detection
 Using Optical Images
 SAR (Synthetic Aperture Radar)
 LiDAR (Light Detection and Ranging)
High-resolution satellite images and aerial photos can be used to detect individual building damage. [20]
Lidar, is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth. These
light pulses—combined with other data recorded by the airborne system — generate precise, three-dimensional information about the
shape of the Earth and its surface characteristics. [21]
https://oceanservice.noaa.gov/facts/lidar.html#:~:text=Lidar%2C%20which%20stands%20for%20Light,variable%20distances)%20to%20the%20Earth
https://www.mdpi.com/2076-3263/10/5/177
SAR, is one of the power tools of remote sensing. Synthetic aperture radar (SAR) bounces a microwave radar signal off the Earth’s surface to detect
physical properties. Unlike optical technology, synthetic aperture radar (SAR) can “see” through darkness, clouds, and rain, detecting changes in habitat,
levels of water and moisture, effects of natural or human disturbance, and changes in the Earth’s surface after events such as earthquakes or sinkhole
openings. [22]
https://asf.alaska.edu/information/sar-information/what-is-
sar/#:~:text=A%20synthetic%20aperture%20radar%20(SAR,backscattered%20%2C%20from%20the%20Earth's%20surface.&text=The%20instrument%20measures%20distances%20between,
where%20the%20signal%20is%20backscattered.

14. TSUNAMI WARNING SYSTEM
 Tsunami boogies were used for wave tracking up-to certain limit waves. If the limit of waves exceeds, Tsunami boogies will transmit
single to the control center and warns for Tsunami.
 A typical tsunami buoy system comprises two components; the pressure sensor anchored to the sea floor and the surface buoy. The
sensor on the sea floor measures the change in height of the water column above by measuring associated changes in the water
pressure. This water column height is communicated to the surface buoy by acoustic telemetry and then relayed via satellite to the
tsunami warning center. [23, 24]
http://www.bom.gov.au/tsunami/about/detection_buoys.shtml#:~:text=What%20is%20a%20deep%2Docean,out%20in%20the%20deep%20ocean.
https://www.kuna.net.kw/ArticleDetails.aspx?id=1847823&language=en
The Indian Tsunami Early Warning System comprises a real-time seismic monitoring
network of 17 broadband seismic stations to detect tsunami genic earthquakes, a network of
real-time sea-level sensors with 4 Bottom Pressure Recorders (BPR) in the open ocean and 25
tide gauge stations at different coastal locations monitor tsunamis and a 24 X 7 operational
tsunami warning centre to provide timely advisories to vulnerable community. It also receives
earthquake data from all other global networks to detect earthquakes of M>6.5. The state-of-
the-art early warning centre at INCOIS - ESSO is operational since October 15, 2007 with all the
necessary computational and communication infrastructure that enables reception of real-time
data from seismic & sea-level sensors, analysis of the data, tsunami modelling, and dissemination
of tsunami advisories guided by a comprehensive standard operating procedure (SOP). [25]
https://en.wikipedia.org/wiki/Tsunami_warning_system

15. Mitigations Techniques
• Planning and practicing for response to tsunamis.
• Alerting the public.
• Establishing, marking, and publicizing evacuation routes.
• Educating the public (residents and visitors) about tsunamis and tsunami safety before a tsunami strikes.
• Improving evacuation routes.
• Building tsunami evacuation structures.
• Limiting new development in tsunami hazard zones.
• Designing, and building structures to minimize tsunami damage.
• Adopting building codes (safety codes) that address tsunamis.
• Protecting and strengthening existing structures and infrastructure that if damaged would negatively affect response and recovery.
• Moving important community assets and vulnerable populations out of tsunami hazard zones.
• Planning for post-tsunami recovery. [26]
https://www.weather.gov/jetstream/prep_com

16. R
e
f
e
r
e
n
c
e
s 1) www.slideshare.net/soubamindrakumar/tsunami-88220119
2) www.livescience.com/3731-tsunamis-history.html
3) https://www.slideshare.net/soubamindrakumar/tsunami-88220119
4) https://commons.wikimedia.org/wiki/File:Harta_Ocean_Indian_Quake.png
5) https://www.researchgate.net/figure/The-2004-tsunami-affected-areas-source-wwwworldatlascom_fig1_310457889
6) https://www.mapsofindia.com/maps/tsunami-in-india/tsunami-affected-area-india.html
7) https://ballotpedia.org/Seismicity
8) https://iotic.ioc-unesco.org/what-causes-tsunami/
9) https://www.google.com/search?q=volcanic+eruption+due+to+tsunami&rlz=1C1FKPE_enIN985IN985&sxsrf=ALiCzsYjAkRj_TzEBPDavjBTjSR6fKkf8w:1652348953883&source=lnms&tbm=isch&sa=X&ved=2ahUKEwikt
MPD19n3AhUJHKYKHZYAB1AQ_AUoAXoECAEQAw&biw=1536&bih=792&dpr=1.25#imgrc=n-XzliUoweKJuM
10) https://iotic.ioc-unesco.org/what-causes-tsunami
11) https://in.pinterest.com/pin/423408802452963161/
12) https://ichef.bbci.co.uk/news/976/cpsprodpb/DFD7/production/_104930375_indonesia_tsunami_explainer_640-nc.png
13) http://itic.ioc-unesco.org/index.php?option=com_content&view=article&id=1205&Itemid=2029#:~:text=There%20are%20three%20factors%20of,houses%20and%20overturn%20railroad%20cars
14) https://www.dw.com/en/climate-induced-sea-level-rise-to-worsen-tsunami-impacts/a-45730449
15) https://www.who.int/health-topics/tsunamis#tab=tab_1
16) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1310941/#:~:text=New%20concerns%20in%20devastation's%20wake,pneumonia%20called%20%E2%80%9Ctsunami%20lung.%E2%80%9D
17) https://www.slideshare.net/soubamindrakumar/tsunami-88220119
18) https://www.sms-tsunami-warning.com/pages/tsunami-effects#.Yn3_HuhBxEY
19) https://en.wikipedia.org/wiki/Tsunami_warning_system
20) https://www.mdpi.com/2076-3263/10/5/177
21) https://oceanservice.noaa.gov/facts/lidar.html#:~:text=Lidar%2C%20which%20stands%20for%20Light,variable%20distances)%20to%20the%20Earth
22) https://asf.alaska.edu/information/sar-information/what-is-
sar/#:~:text=A%20synthetic%20aperture%20radar%20(SAR,backscattered%20%2C%20from%20the%20Earth's%20surface.&text=The%20instrument%20measures%20distances%20between,where%20the%20signal
%20is%20backscattered.
23) http://www.bom.gov.au/tsunami/about/detection_buoys.shtml#:~:text=What%20is%20a%20deep%2Docean,out%20in%20the%20deep%20ocean
24) https://www.kuna.net.kw/ArticleDetails.aspx?id=1847823&language=en
25) https://en.wikipedia.org/wiki/Tsunami_warning_system
26) https://www.weather.gov/jetstream/prep_com

17. @CHITTURILAVANYA