Classifying & Locating Natural Hazards

Classifying & Locating Natural Hazards

Magnitude (vs) Intensity Magnitude

An assessment of the size of an event But what characteristic property is measured?

▪ Wind speed? Barometric Pressure? Eye diameter? What unit?

▪ m/s, km/h

Intensity An assessment of the impact of a disaster But what aspects of damage are considered?

▪ Was it observed by people?▪ Property damage?▪ Death?

Unitless…a ranking▪ Category

Hurricanes – Saffir Simpson Scale

Cat Effects

1 No real damage to building structures. Damage primarly to unanchored mobile homes, shrubbery, and trees. Also, some coastal road flooding and minor pier damage

2Some roofing material, door, and window damage to buildings. Considerable damage to

vegetation, mobile homes, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of center. Small craft in unprotected anchorages break moorings.

3Some structural damage to small residences and utility buildings with a minor amount of

curtainwall failures. Mobile homes are destroyed. Flooding near the coast destroys smaller structures with larger structures damaged by floating debris. Terrain continuously lower than 5 feet ASL may be flooded inland 8 miles or more.

4More extensive curtainwall failures with some complete roof strucutre failure on small

residences. Major erosion of beach. Major damage to lower floors of structures near the shore. Terrain continuously lower than 10 feet ASL may be flooded requiring massive evacuation of residential areas inland as far as 6 miles.

5Complete roof failure on many residences and industrial buildings. Some complete

building failures with small utility buildings blown over or away. Major damage to lower floors of all structures located less than 15 feet ASL and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground within 5 to 10 miles of the shoreline may be required.

Saffir-Simpson Hurricane Intensity Scale

5

http://www.weather.com/video/hurricane-categories-make-a-difference-38272

http://www.youtube.com/watch?v=eW3W1on9vjMHurricane Katrina

http://www.youtube.com/watch?v=j-zczJXSxnwTacoma Bridge

6http://allanawheeler.files.wordpress.com/2011/05/mms.jpg

Earthquakes – Moment Magnitude

7

Haiti Earthquake - 2010Magnitude 7.0

8

9

Volcanoes (VEI)Volcanic explosivity

indexBlast

duration(hours)

< 1

<1

<1

<6

<12

>12

>12

>12

>12

Blast duration(hours)

< 1

<1

<1

<6

<12

>12

>12

>12

>12

11

• http://www.youtube.com/watch?v=xP2dreOI8gI

• Mt. St Helens– Plinian

12

Papadapoulos-Imamura Scale (Tsunami)

Not feltScarcely felt

WeakLargely observed

StrongSlightly damaging

DamagingHeavily damaging

DestructiveVery destructive

DevastatingCompletely devastating

13

• http://www.youtube.com/watch?v=1J8Feyr38Ss

• 2004 Tsunami

14

Fujita ScaleTornadoes

64 to 116

117 to 180

181 to 252

253 to 330

331 to 417

Wind Speedkm/hr

418 to 509

510 to sonic

15

http://www.youtube.com/watch?v=gieSbj2svwYFujita Scale

16

Torino Scale: Impact Risk(NEOs)

Near-earth objects – asteroids and comets

Events Having No Likely Consequences

(White Zone)

0

The likelihood of a collision is zero, or well below the chance that a random object of the same size will strike the Earth within the next few decades. This designation also applies to any small object that, in the event of a collision, is unlikely to reach the Earth's surface intact.

Events Meriting Careful Monitoring

(Green Zone)

1

The chance of collision is extremely unlikely, about the same as a random object of the same size striking the Earth within the next few decades.

Events Meriting Concern

(Yellow Zone)

2

A somewhat close, but not unusual encounter. Collision is very unlikely.

3

A close encounter, with 1% or greater chance of a collision capable of causing localized destruction.

4

A close encounter, with 1% or greater chance of a collision capable of causing regional devastation.

17

Torino Scale: Impact Risk

Threatening Events (Orange Zone)

5 A close encounter, with a significant threat of a collision capable of causing regional devastation.

6 A close encounter, with a significant threat of a collision capable of causing a global catastrophe.

7 A close encounter, with an extremely significant threat of a collision capable of causing a global catastrophe.

Certain Collisions

(Red Zone)

8 A collision capable of causing localized destruction. Such events occur

somewhere on Earth between once per 50 years and once per 1000 years.

9 A collision capable of causing regional devastation. Such events occur between once per 1000 years and once per 100,000 years.

10 A collision capable of causing a global climatic catastrophe. Such events occur once per 100,000 years, or less often.

18

Current Impact Risks

http://neo.jpl.nasa.gov/risks/

Mars

Moon

Mercury

Ida-243

Impact craters are found on any planetary body with a solid surface

Earth’s Known Impact Structures

Earth retains the poorest record of impact craters amongst terrestrial planets Plate tectonics - Erosion – Sedimentation - Life

Oceans are relatively young and hard to exploreAtmosphere

Why?

Manicouagan, Canada (62 mi)

Roter Kamm, Namibia (1.6 mi)

Brent, Canada (2.4 mi)

Wabar, Saudi Arabia (0.072 mi)

Vredefort, South Africa (125-185 mi)

Meteor Crater, AZ (0.75 mi)

Wolfe Creek, Australia (0.55 mi)

Spider, Australia (8.1 mi)

Popigai, Russia (62 mi)

22

23

Tunguska Event, Siberia

Aerial explosion of a stony asteroid, 25-50 m diameter

7:00 am June 30, 1908

Blue-white fireball wih glowing tail descendedExploded above Tunguska Valley forest10 Mt of TNT, 10 H-bombsSound heard over area of 1 million km2

Flattened and burned 2000 km2

Once every 300 years!

24

Tunguska Event, (Russia)

http://www.youtube.com/watch?v=EiXpp-i442s

25

26

Odds of dying:Motor vehicle accident 1 in 100Asteroid impact (optimal chance) 1 in 3000Flood 1 in 30,000Tornado 1 in 60,000Asteroid impact (worse chance) 1 in 250,000

27

http://www.cnet.com/news/odds-of-dying-from-an-asteroid-strike-

1-in-74817414/

28

http://news.nationalgeographic.com/news/2014/05/140512-asteroid-

impact-winter-science/

29

Blizzard

A severe winter storm lasting four or more hours. It is characterized by significant wind chill, strong winds and poor visibility due to blowing snow.

visibility < 1 km wind speeds of >40 km/hwind chill of -25ºC or colderDuration 4+ hours

Environment Canadahttp://www.mb.ec.gc.ca/air/wintersevere/blizzards.en.html

30

Blizzards in Canada:

• 1 Alberta Clipper• 2 Maritimes Nor’easter• 3 Colorado Low

31

• http://www.theweathernetwork.com/news/articles/remembering-white-juan-10-years-later/21728/

32http://rsta.royalsocietypublishing.org/content/364/1845/2147/F2.large.jpg

World Map of Natural Hazards. Earthquake hazard is shown in yellow–brownish colours and has been classified into five grades according to the minimum intensity (Modified Mercalli scale) to be reached or exceeded once in 475 years. Darkest colour means highest hazard. The hazard of tropical windstorms is presented in green colours, again darkest colour corresponds to highest hazard. Classification is according to the five degree Saffir–Simpson scale. Green arrows represent the main cyclone tracks. Other hazards shown are extratropical storms (grey shading) and active volcanoes (small black symbols).

Add to CiteULike

33

In Summary…

• Hurricanes – Saffir Simpson Scale• Earthquakes – Moment Magnitude Scale• Volcanoes – VEI index• Tsunamis - Papadapoulos-Imamura Scale• Tornadoes – Fujita Scale• Impacts (NEOs) – Torino Scale• Severe Snowstorms - Blizzards

34

Play Blizzard!