geologic hazards and space geodesy

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geologic hazards and space geodesy

• part 4 integrating GPS into warning and response

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Can we design a better tsunami alert system?

• Reduce false alarms
• dont cause panic educate people on how to react
• Warn everybody - needs to be in the right
  language
• Broadcast
• Radio
• TV
• Satellite telecommunication
• Cell phone
• GPS
• Sirens or Loudspeakers? One can trigger the next
  so as to propagate the alarm rapidly (not
  backwards, dont want to jam comms with a
  back-propagating notification)
• Buoy system can directly notify and propagate
  alert signal through satellite and all other
  telecomm links immediately
• Airplane, blimp or helicopter with loudspeakers
  or sign towed behind it?

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Can we design a better tsunami evacuation, safety
and survival system? (some of the solutions need
to work even for very low-lying islands and other
coastal plain areas)

• Underground bunker (waterproof hatches like a
  submarine)
• Strong tall buildings with extra capacity
  stairwells for people to run up very quickly to
  higher levels where its safe, and lots of
  emergency supplies, water and food stored up high
• Could have a big red flashing light and siren on
  top
• Boats with large capacity that can launch quickly
  and get out into deep water very fast
• Airplanes with large capacity that can get
  airborne quickly
• Helicopters with tremendous lifting capacity so
  that they can sling-load many people to safe high
  ground, load after load
• Special roads heading straight to high ground,
  which could have special high-capacity cars to
  move quickly and make many trips back and forth
  to shuttle many people

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Basic warning elements

• Know an event happened as fast as possible
• Know the location of an event
• Know the size of an event
• Know the probability that an event produced a
  tsunami

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AUTOMATED TAGGING AND REAL-TIME DAMAGE
DISTRIBUTION MAPS
Automated Tagging and Real-Time Damage
Distribution Maps

• Multiple sensor package
• Acceleration / Velocity
• Displacement (GPS)
• Rotation (tilt-meter)

• Pre-earthquake
• Reference static displacement
• Reference static rotation
• Mean and variance of
• dynamic characteristics

• Post-earthquake
• Permanent static displacement
• Permanent static rotation
• Mean and variance of
• dynamic characteristics

• During earthquake
• Changes in dynamic
• characteristics
• Hysteretic behavior
• Damage initiation

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GPS real-time displacement
1-Hz data
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• Caltech Tectonic Observatory GPS Array

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GPS buoy systems

• NOAA DART buoys are expensive and high
  maintenance
• GPS can be used for large numbers of low-cost
  buoys to complement existing system
• NavCom-AXYS contract for US Navy (NAVOCEANO)
  2 cm inshore, 10 cm offshore
• NOAA-USGS testing program for warning application
• Tie in with existing earthquake and weather
  monitoring and alerts

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Other data sets
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Basic response elements

• Know the location of damage
• Know the extent of damage
• Know the type of damage and therefore the
  response required

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GPS results

• GPS surveys before and after the earthquake are
  differenced to obtain 3D vectors of permanent
  deformation (courtesy of CESS, SEIRES)
• Deformation data are modeled to obtain slip on
  the fault plane, especially in areas
  complementary to seismology

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• Bilham et al., in press SRL

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Remote sensing

• (a) Pre-earthquake and (b) post-earthquake
  Advanced Space-borne Thermal Emission and
  Reflection Radiometer (ASTER) images of North
  Sentinel Island, showing emergence of the coral
  reef surrounding the island. (c) Pre-earthquake
  and (d) post-earthquake ASTER images of a small
  island off the northwest coast of Rutland Island,
  38 km east of North Sentinel Island, showing
  submergence of the coral reef surrounding the
  island. The pivot line must run between North
  Sentinel and Rutland islands. Note that the scale
  for the North Sentinel Island images differs from
  that for the Rutland Island images. Scale bars as
  follows left (a-b) 0-6 km right (c-d) 0-1 km.
  (ASTER images courtesy of NASA/JPL from Meltzner
  et al., 2006).

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What do GPS and Before After images tell us?

• Derive damage assessment maps
• Indicate areas most severely affected by shaking
  inundation
• Provide rapid and comprehensive information
  needed in support of decisions on prioritization
  for resource deployment
• Help with vital logistical aspects of relief
  efforts (e.g., Can ports be used for shipping?
  Are bridges knocked out? Where are survivors?)
• Validate verify rapidly estimated finite-fault
  slip models (e.g., predicted vs. observed coastal
  uplift submergence)
• provide important input data to refine fault
  source models
• Tsunami inundation map data as input to tsunami
  propagation models
• Flood data to assess saline infiltration and
  damage to irrigable lands and water supplies is
  flooding permanent or transient?
• Commercial and other imagery and analysis tools
  have reached a new level of utility with recent
  disaster responses
• still require calibration, ground-truthing,
  validation, and algorithm software development
• promising for future rapid assessment
  quantification

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California
Prototype GPS fault slip sensor up to 10 Hz
Spans the San Andreas fault near Gorman,
California
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San Andreas - instrument majorlifeline
infrastructure crossings
L A
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Cajon Pass I-15 Fault Crossing
Need a real-time GPS array right here...
need before (B4) and after imaging for
rapid assessment of damage to lifeline
infrastructure
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California