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Natural Disasters M. Borowik N. Murray K. Nabbs A. Pakebusch An Overview of Natural Disasters; Tornadoes, Earthquakes, Volcanoes, and Tsunamis

Natural Disasters

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Page 1: Natural Disasters

Natural Disasters

M. Borowik

N. Murray

K. Nabbs

A. Pakebusch

An Overview of Natural Disasters; Tornadoes,

Earthquakes, Volcanoes, and Tsunamis

Page 2: Natural Disasters

Informational Resources and their

Credibility

This presentation contains information from online resources that were selected using Metzger (2007) recommended assessment of credibility criteria for online information. In particular, resources were chosen based on;

Accuracy – the degree to which online sources are free from error, and can be verified offline.

Authority – qualifications and affiliations of the author or organisation, as well as availability of contact information.

Objectivity – the underlying purpose of the source (i.e commercial intent), transparency, and whether source information is considered to be fact or opinion.

Currency – whether provided information is up to date.

Coverage – refers to quality and depth of information provided by the source.

Consequently, credible online resources derive fact from carefully deducted theory, provide highly accurate data, and offer objective evidence (with no commercial intent) to support their conclusions (Metzger, 2007).

Page 3: Natural Disasters

What are Natural Disasters?

Natural disasters are serious disruptions to

regions or communities by a

naturally occurring, rapid phenomena that causes injury, death,

or damage to property or the environment.

Natural disasters require substantial co-ordinated involvement

of Government organisations and

community groups.

Australia.gov.au (2015).

Page 4: Natural Disasters

Tornadoes

Earthquakes

Volcanic Eruptions

Tsunamis

Bushfires

Hurricanes

Cyclones

Floods

Avalanches

Blizzards

Storms

Other

• Tornadoes, Earthquakes, Volcanic Eruptions, and Tsunamis.

There are many types of natural disasters, these are

just some examples. However, this presentation will focus on;

What Types of Natural Disasters Exist?

Page 5: Natural Disasters

What is an Earthquake?

Geoscience Australia, a prescribed Government agency, defines earthquakes

as violent shaking (called seismic waves) of the ground resulting from tectonic

plate movement (sublayers of the earths crust).

What Causes Earthquakes?

Earthquakes are caused by a sudden release

of energy (due to compression in

the earths crust) along fault planes

(weak points in tectonic plates).

(Geoscience Australia, 2014).

What is an Earthquake?

Page 6: Natural Disasters

Destruction and Historical Events

The most destructive earthquake in history

occurred near Shaanxi, China in 1556.

Earthquake damage was reported to have

extended across 270 km from the

epicentre (centre of the earthquake).

Based on these reports, the earthquake was estimated

to have measured an 8 on the Richter magnitude scale

(10 being the highest score).

More than 830,000 soldiers and citizens were reported to have died as a

result.

(United States Geological Survey, 2014)

How Destructive are Earthquakes?

Page 7: Natural Disasters

What Warning Systems Exist for

Earthquakes?

Warning Systems

Early Earthquake Warning (EEW) systems utilise

ground motion sensors to detect early vibrations

generated by earthquakes.

ShakeAlert (an EEW system) works by detecting

initial earthquake waves (which travel fastest)

giving people a few seconds to minutes to take

precautionary actions before the arrival of the

slower but stronger earthquake waves.

Members of the public can program their computers and mobile phones to

receive alert messages from EEW systems.

(Burkett, Douglas, Given, & Jones, 2014)

Page 8: Natural Disasters

What Precautions are put in place for

Earthquake Hazard Areas?

Precautions

People are advised to prepare a basic emergency kit (water, food, first aid,

etc.), and a family emergency plan (families should discuss how they will

contact each other in case of an emergency, and what to do when alerted of

an earthquake).

All book cases, filing cabinets, picture frames, and light fixtures should be

safely anchored to walls.

Members of the public, and business owners are recommended to hold regular

emergency evacuation

drills.

(The Ready Campaign, 2014)

Page 9: Natural Disasters

What is a Tsunami?

What is a Tsunami?

Tsunami is derived from the Japanese

words ‘tsu’ meaning harbor, and ‘nami’

meaning wave.

A tsunami is a large wave resulting from an

earthquake, landslide or volcanic eruption

in or adjacent to an ocean.

The result is fast-moving, destructive wave

that often causes inland flooding.

Ga.gov.au (2015)

Source: Thirty-Six Views of Fuji (1831)

Page 10: Natural Disasters

What Causes Tsunamis?

What Causes Tsunamis?

Earthquakes are the most common cause of tsunamis

Underwater seismic vibrations often produce fast

moving waves that flood neighboring coasts.

Landslides

Land slumps that hit the ocean can result in an

underwater landslide, and in turn, a tsunami.

Volcanic Eruptions

Tsunamis caused by volcanic eruptions are least

common

A volcanic eruption near a large body of water can

sometimes result in a quick ground uplift, followed by a

quick drop, and a subsequent tsunami wave.

(Geoscience Australia, 2014).

Source: Geoscience Australia

Page 11: Natural Disasters

How Destructive are Tsunamis?

Destruction and Historical Events

The most destructive tsunami in history

occurred in Sumatra, Indonesia in 2004.

The tsunami was the result of a 9.1

magnitude earthquake (pictured).

The tsunami wave reached a height of 50

meters, and flooded 5km of land.

The Sumatran tsunami was also reported

to have significantly increased wave height

across the US, UK and Antarctica.

230,000 people were reported dead, and

the tsunami was estimated to have cost US

$10 billion worth of damages (Phillips, C

2011) Sumatra tsunami, source Guy Gelfenbaum, USGS

Page 12: Natural Disasters

Historical Tsunamis

The most recent and second most powerful tsunami

occurred in Japan, in 2011.

More than 18,000 people were killed as 10m high waves

swept over Japan at 800km per hour (Phillips, C 2011)

Result of a 9.0 magnitude earthquake.

Destroyed approximately 452,000 peoples homes.

Unique to this tsunami, a nuclear emergency resulted due

to subsequent damage to the Fukushima Daiichi nuclear

power plant.

It is estimated it will take Japan 5 years to financially

overcome the $235 billion in damages

(Phillips, C 2011)

Page 13: Natural Disasters

What Warning Systems Exist for

Tsunamis?

Warning Systems

Unpredictability, infrequency and unique causes

have made forecasting tsunamis very difficult

International Tsunami Warning System

Monitors ocean waves after any Pacific earthquake

with magnitude over 6.5

If necessary, warnings are then issued to local

authorities to evacuate low-lying areas

National Oceanic and Atmospheric Administration

(NOAA) operates 2 centers

West Coast/Alaska Tsunami Warning Center

Pacific Tsunami Warning Center

Source: Hydro International

Page 14: Natural Disasters

What Precautions are put in place for

Tsunami Hazard Areas?

Precautions

A number of precautionary measures are in

place for communities in tsunami hazard

areas, including;

Evacuation orders based on the height of your

street above sea level and distance from the

coast.

Evacuation zones ideally within 15 minutes walk

that are located at least 30 m above sea level

and 3 km inland.

Regular practice taking evacuation routes,

especially in low-level light.

Familiarising tourists with evacuation protocolsSource: jaxshells.org

Page 15: Natural Disasters

What is a Volcanic Eruption?

A volcanic eruption occurs when a there is a

sudden, and violent release of volcanic

material (gas, ash, molten rock) from

underneath the earth.

Volcanic lava can reach temperatures of 700

to 1,200 Celsius.

The most commonly recognised volcano eruption (the volcanic eruption cone)

occurs as a result of tectonic plate movements. Over the course of many

years, volcanic material begins to harden around the volcano vent, giving it a

mountain like appearance.

Not all volcanoes erupt above sea level, there are a significant number of

volcanoes that erupt underneath oceans.

(Bom.gov.au, 2015)

Page 16: Natural Disasters

What Causes Volcanic Eruptions?

Earths crust is comprised of 17 tectonic plates that continually move on top of

earths mantle (a layer between the crust and the outer core). Volcanic

eruptions occur when these tectonic plates diverge movement of these

tectonic plates. Volcanoes also form when there is stretching and thinning of

the earth’s crusts.

Volcanic eruptions occur when gas trapped

beneath these tectonic plates violently

extrudes onto earths crust along with molten

rock from within earths mantle.

The strength of volcanic eruptions depends

on gas pressure, and the ease with which

lava is able to flow.

(Ga.gov.au, 2015)

Page 17: Natural Disasters

How Destructive are Volcanic

Eruptions?

The 2010 eruption of the Icelandic volcano,

Eyjafjallajokull substantially disrupted Europe's

political and cultural activities.

Over 95,000 flights were cancelled due to the

extensive spread of volcanic ash across Europe.

An estimated U.S $1.7 billion was lost by the

airline industry as a direct result of the eruption.

The volcanic ash cloud was 6-10 km in height and lasted approximately 6 days.

As the volcanic eruption was well predicted, there were no human fatalities.

(Volcanoes.usgs.gov, 2015)

Page 18: Natural Disasters

What Warning Systems Exist for

Volcanic Eruptions?

Volcanic eruptions can be predicted by monitoring of seismic activity (i.e

minor earthquakes occur prior to an eruption).

Increasing levels of sulphur dioxide, and decreasing pressure of magma as it

nears the surface (enabling carbon dioxide to escape) signals an oncoming

eruption.

Geologists measure the tilt of the

volcano slope. An increased rate of

swelling indicates accumulation

of magma, and in turn, an eruption.

(Volcanoes.usgs.gov, 2015)

Page 19: Natural Disasters

What Precautions are put in place for

Volcano Eruption Hazard Areas?

Governments outline clear evacuation and

medical plans for members of the public, and

affected industries.

News broadcasters regularly report updates

received from volcanic monitoring centres.

During an eruption, public members are advised

to stay clear of river areas and low-lying regions.

Individuals are advised to prepare an emergency

kit, as well as to wear long-sleeved shirts, long

pants, and use goggles or eyeglasses during

evacuation.

(Society, 2015)

Page 20: Natural Disasters

What is a Tornado?

What is a Tornado?

Tornadoes is from the Spanish word, tronada, meaning

thunderstorm

A Tornado is as a rotating, funnel-shaped cloud that

extends from a thunderstorm to the ground with whirling

winds that can reach 300 mph.

Waterspouts are tornadoes that form over a body of

water

Thunderstorms most likely to give birth to Tornadoes are

called supercells

Usually a tornado starts off as a white or grey cloud but

if it stays around for a while, the dirt and debris it sucks

up give it a dark appearance. Source: markdmckinney.com

Page 21: Natural Disasters

What Causes Tornadoes?

What Causes a Tornado?

A Tornado normally begins with two winds coming

together at very high speeds. Upward and downward

winds traveling at different levels of the atmosphere

result in an updraft and give the tornado's its funnel-

like appearance.

Tornadoes form in unusually violent thunderstorms

when there is sufficient wind instability in the lower

atmosphere.

(Tornado-facts.com, 2015)

Source: Tornado Facts – Gallery of Tornado Pictures

Page 22: Natural Disasters

How Destructive are Tornadoes?Rank Date Estimated Intensity* State Injuries (Deaths) Remarks

1 March 18, 1925 EF-5 MO, IL, IN 2,027 (695)

Tri-State Tornado

Wikipedia Entry (link is external)

Tornado Project Page (link is external)

2 May 6, 1840 Unknown LA, MS 109 (317)

Hit Nachez, MS

Wikipedia Information (link is external)

Tornado Project Page (link is external)

3 May 27, 1896 EF-4 MO, IL 1,000 (255)

The Great St. Louis Tornado

Tornado Project Page (link is external)

The Great Cyclone. SIU Press (link is external)

St. Louis American Local History Network (link is

external)

4 April 5, 1936 EF-5 MS 700 (216)Hit Tupelo, MS

Tornado Project Page (link is external)

5 April 6, 1936 EF-4 GA 1,600 (203)

Hit Gainesville, GA

Tornado Project Page (link is external)

About N. Georgia (link is external)

6 April 9, 1947 EF-5 TX, KS, OK 970 (181) Tornado Project Page (link is external)

7 May 22, 2011 EF-5 MO 1,000 (158)Hit Joplin, MO

NWS Summary

8 April 24, 1908 EF-4 LA, MS 770 (143)Hit Amite, LA and Purvis, MS

Tornado Project Page (link is external)

9 June 12, 1899 EF-5 WI 200 (117)Hit New Richmond, WI

Tornado Project Page (link is external)

10 June 8, 1953 EF-5 MI 844 (116)Hit Flint, MI

Tornado Project Page

(Dosomething.org, 2015)

Page 23: Natural Disasters

What Warning Systems Exist for

Tornadoes?

The most common form of Tornado warning is a siren that

will sound when there is a imminent threat of a tornado.

The Tornado warning is generally issued when the

meteorological radar indicates the formation of a tornado,

however this is not always the case. The warning can also

be issued if a funnel cloud is spotted by;

A member of the public

Storm chasers

Emergency management

Law enforcement

When these sirens are sounded, residents are advised to

take immediate safety precautions (i.e seek underground

shelter).

(Markdmckinney.com, 2015)

Page 24: Natural Disasters

What Precautions are put in place for

Tornado Hazard Areas?

Source: ravingreader.wordpress.com

Tornado Alley is a nickname given to an area in the

southern plains of the central United States. The area is

known for experiencing a high frequency of tornadoes.

Tornadoes in this region typically occur in late spring and

early fall.

Residents are well informed in taking emergency

precautions when alerted of a tornado (i.e stay inside

away from windows, keep low to the ground, etc.)

Some residents have their own purpose built tornado

shelters

Residents are advised to wait for emergency services

if impacted by a tornado

(Tornado-facts.com, 2015)

Page 25: Natural Disasters

References

Australia.gov.au,. (2015). natural-disasters | australia.gov.au. Retrieved 21 January 2015, from http://www.australia.gov.au/about-australia/australian-story/natural-disasters

Australiangeographic.com.au,. (2015). The 10 most destructive tsunamis in history. Retrieved 21 January 2015, from http://www.australiangeographic.com.au/topics/science-

environment/2011/03/the-10-most-destructive-tsunamis-in-history/

Bom.gov.au,. (2015). BoM-Darwin Volcanic Ash Advisory Centre. Retrieved 21 January 2015, from http://www.bom.gov.au/info/vaac/

Dosomething.org,. (2015). 11 Facts About Tornadoes | DoSomething.org | America's largest organization for youth volunteering opportunities, with 2,700,000 members and

counting. Retrieved 21 January 2015, from https://www.dosomething.org/facts/11-facts-about-tornadoes

Earthquake.usgs.gov,. (2015). Earthquakes with 50,000 or More Deaths. Retrieved 21 January 2015, from http://earthquake.usgs.gov/earthquakes/world/most_destructive.php

Ga.gov.au,. (2015). About Us - Geoscience Australia. Retrieved 21 January 2015, from http://www.ga.gov.au/about

Ga.gov.au,. (2015). What is a Tsunami? - Geoscience Australia. Retrieved 21 January 2015, from http://www.ga.gov.au/scientific-topics/hazards/tsunami/basics/what

Historyofgeology.fieldofscience.com,. (2015). History of Geology: Historic tsunamis in Japan. Retrieved 21 January 2015, from

http://historyofgeology.fieldofscience.com/2011/03/historic-tsunamis-in-japan.html

http://distriqt.com, d. (2015). Australian Emergency Management Knowledge Hub. Australian Emergency Management Knowledge Hub. Retrieved 21 January 2015, from

https://www.emknowledge.gov.au/connect/tsunami-the-ultimate-guide/#/

Hydro-international.com,. (2015). Full-scale Test of Indian Ocean Tsunami Warning System - News - Hydro International. Retrieved 21 January 2015, from http://www.hydro-

international.com/news/id5118-Indian_Ocean_Tsunami_Warning_System_Test.html

Page 26: Natural Disasters

References - Continued

Markdmckinney.com,. (2015). Tornado Facts. Retrieved 21 January 2015, from http://markdmckinney.com/tornadofacts.html

Ncdc.noaa.gov,. (2015). Deadliest Tornadoes | National Climatic Data Center (NCDC). Retrieved 21 January 2015, from http://www.ncdc.noaa.gov/climate-information/extreme-

events/us-tornado-climatology/deadliest

Ready.gov,. (2015). Earthquakes | Ready.gov. Retrieved 21 January 2015, from http://www.ready.gov/earthquakes

Redcross.org,. (2015). Tsunami Survival | What to Do & How to Survive | Red Cross. Retrieved 21 January 2015, from http://www.redcross.org/prepare/disaster/tsunami

Society, N. (2015). Environment Facts, Environment Science, Global Warming, Natural Disasters, Ecosystems, Green Living - National Geographic. National Geographic. Retrieved

21 January 2015, from http://environment.nationalgeographic.com

Spaceplace.nasa.gov,. (2015). NASA's Space Place :: Home :: NASA's The Space Place. Retrieved 21 January 2015, from http://spaceplace.nasa.gov

Tornado-facts.com,. (2015). Amazing Tornado Facts | Tornado Facts. Retrieved 21 January 2015, from http://tornado-facts.com/amazing-tornado-facts/

Volcanoes.usgs.gov,. (2015). Volcano Hazards Program. Retrieved 21 January 2015, from http://volcanoes.usgs.gov/

www.hawaiiactive.com,. (2015). Hawaii Activities - Best Things To Do in Hawaii. Retrieved 21 January 2015, from http://www.hawaiiactive.com