Best Intro and Ch1

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					         Geology 112
       Geologic Disasters
 Instructor: Dr. David M. Best
 Contact: Phone 523.7205 or e-mail
  David.Best@nau.edu (Please use
  GLG 112 in the subject line)
 Office: Geology Annex Room 203
 Office Hours: 1:30p – 2:30p T
  or by appointment (send e-mail)
Textbook for lecture:
  Earth’s Natural Hazards, 2010, Best and Hacker,
  Kendall Hunt Publishing Co.

Web site:
 http://oak.ucc.nau.edu/dmb25

You should bookmark this web address
          Course Objectives
 Be   able to:
  – examine the way in which Earth and
    humankind have been affected by
    natural disasters
  – demonstrate how different processes at
    work on Earth are often interrelated
  – use relevant information in the future to
    understand natural disasters as they
    occur and to prepare for them
Course Expectations/Outcomes
 Develop  new vocabulary
 Understand processes at work on
  Earth that cause disasters
 Be able to understand why events
  happen and how their effects can be
  reduced
 Do well in the course and come out
  with an appreciation of the subject
  matter
          Course Structure
 Lecture-based
  – We meet Monday through Thursday for
    lecture
  – Class participation and discussion are
    encouraged
  – Several videos which could produce
    exam questions
  – Read material prior to covering it in
    lecture
  – Class attendance is critical in this course
         Grade determination
                              Points
   Three exams               300
       TOTAL                  300

    – A = 90% or higher    270 or more
    – B = 80 – 89.9       240-269
    – C = 70 – 79.9       210-239
    – D = 55 – 69.9       165-209
    – F = <55             < 165
           General comments
 Metric   system is used in the sciences
  – Distances – meters/kilometers
  – Temperatures – Celsius
  – Mass/Weight – gm and kg
 We will sometimes refer to units in
 the US/British system [miles,
 Fahrenheit]
             Let’s begin!
Geology
  – Greek: geo – Earth; logos – discourse


Physical geology looks at Earth’s
 materials and processes
Historical geology examines Earth’s
 origin and development through time
We will examine aspects of each of
 these in discussing disasters
                   Key points
Earthquakes – floods – typhoons /hurricanes/cyclones –
tsunami – wildfires – landslides – impacts:

       all these events require an energy source, either
               gravity or thermal

In the past decade more than two-thirds of the deaths have
been caused by water-related events

Cyclonic storms, earthquakes and tsunami have caused the
greatest loss of life from natural disasters in the past 50
years (diseases always rank first in terms of all causes)
 Greatest   losses have occurred in Asia
  – Why?
     Most people
     Poor communications

     Poor construction

     Many people in low-lying areas

     Very active geologic areas
   Post-event effects (often not considered)
    – Increased suicide rate
    – Disrupted life style – consider areas in South Asia
      affected by the Dec 2004 tsunami, the US Gulf Coast
      region after Katrina (Aug 2005), California wildfires
      (2005-2008), Haiti earthquake (Jan 2010), the Gulf oil
      spill (Mar 2010), Japan earthquake and tsunami (Mar
      2011), tornadoes in South (Apr 2011), Miss River floods
      (May 2011)
    – Economic losses
        Total annual losses are skewed by 1-2 events which
          occur in developed countries
          – Consider the events in New Orleans with H. Katrina
            (2005) estimated at a minimum of $45 billion; Japan
            tsunami (Mar 2011) estimated at $150 billion or more
        Tsunami  damage (Dec 2004) had far reaching effects
         but poorer areas were affected
        Insurance sometimes helps
          – Flood insurance is very risky, but not always available
   Average annual loss of life worldwide ~150,000
   Cost ~ $50 billion per year in terms of property, mainly in
    developed countries
   Major losses in recent years
     – 1976 China EQ                  255,000 deaths
     – 1985 Colombia volcano           23,000
     – 1991 Bangladesh cyclone        140,000
     – 2004 Dec 26th tsunami          230,000
     – 2005 Aug 29th Katrina             1,800
     – 2008 May Myanmar (Burma) 138,000
     – 2008 May China EQ               68,700
     – 2010 Jan 12 Haiti earthquake 220,000
     – 2011 Mar 11 Japan EQ/tsunami 18,000

    Largest loss of life historically has been by famine and
      disease
    Global events since January 1st

 Major landslides in Brazil
 Major flooding in Queensland, Australia
 Cold weather across Midwest and New
  England
 Earthquake in Christchurch, NZ
 Japan earthquake and tsunami
 Tornadoes in South (NC, AL, GA, MS)
 Major flooding along Mississippi River
   Examples of reoccupied areas
    –   Mt Vesuvius and Mt Etna [Italy]
    –   Portions of California along San Andreas fault
    –   Various areas in South America in Andes
    –   East and Gulf coasts of US
    –   Japan and the Philippine Islands
 Note that in most cases there is NO
  alternative place to relocate
 Impact areas change due to shifts in
  population, more urbanization, changes in
  the terrane (hillslopes, drainage,
  vegetation)
      Rapid vs. slow events
 Rapid-onset
  – Very evident in real-time
  – Earthquake, volcano, tsunami, landslide
 Slow-onset
  – Less evident or detectable
  – Drought, climate change, diseases
                       Descriptor terms
   Magnitude
    – The “size” of an event as measured on some scale, such as the
      Richter scale for EQs, the Enhanced Fujita scale for tornados,
      or the Saffir-Simpson scale for hurricanes; energy related

   Frequency
    – How often a specific type of event occurs
           Too many variables exist to provide any meaningful way to truly
            predict an event; thought of as a rough average
           Large events occur less often; small ones more often – so this is
            an inverse relationship (magnitude-frequency idea)

   Return period or recurrence interval
    – Number of years between same-sized events
    – Usually the larger and more energetic the event, the longer
      the return rate
    – Floods are spoken of in terms of the “100-year flood” meaning
      a chance of 1 in 100 (1%) that the event occurs in a given
      year
Population
doubles
roughly every
53 yrs

Doubling time
is found by:

70 divided by
% annual
growth

So 2%
growth
doubles
population in
35 yrs
Population by global regions
Changes in world population
   Understanding and assessing
            hazards
 We   need
  – Historic and recent prehistoric data
  – Recurrence intervals
  – Review of maps and aerial imagery
  – Review of stream deposits, when
    appropriate
  – Current geologic conditions
 Events  are termed hazardous only
 because we’ve chosen to develop in
 areas affected by natural processes,
 e.g., floodplains
     What drives the Impact
 Human      fatalities
     Type of disaster
     Location of occurrence

     Time of day

     Communication capabilities

 Economic     losses
     Type of disaster
     Location of occurrence

     Construction standards
 Environmental     damage
     Type of disaster
     Location of occurrence

     Sustainability of environment

     Environmental recovery potential
                  Scientific Inquiry
   Hypothesis
    – An untested, proposed explanation for facts,
      measurements or observations
          Example: more study hours             better grades
    – Results must be repeatable with predictable results
   Theory
    – Results from the survival of extensive examination of
      competing hypotheses related to the topic
          Example: Theory of Relativity; Theory of Plate Tectonics
   Principle or Law
    – Scientific theories that are absolutely correct
          Example: Law of universal gravitation; Law of Natural
           Selection
                       Natural hazards
   Hazard – any natural process that poses a threat to human life or
    property; these are predictable and repetitive

   Disaster – the effect a hazard produces, usually over a limited time period
    in a fairly well-defined geographic area.

   Catastrophe – a massive disaster; recovery time is significant, in months
    or years, and process of recovery is complex.

   Areas that are likely to have natural disasters but have not experienced
    them are considered as being potential
     – Slopes of volcanoes or steep mountains
     – Shorelines in “hurricane alley’
     – Floodplains of rivers

   Mitigation (reduction of effects) or prevention steps must be considered
     – People often reoccupy destroyed areas, making it difficult to mitigate future
       problems
     – Events will occur again (recurrence rates)
     – What about New Orleans?
     – What about California?
              Mitigation

 Planning

 Identificationof hazards
 Assessing likelihood

 Communication

 Prediction

 Preparedness

 Response and recovery

				
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posted:10/10/2011
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