1 detecting tsunami power / scale directly from coastal gps stations for early warnings...
TRANSCRIPT
1
Detecting Tsunami Power / Scale Directly from Coastal GPS Stations for Early Warnings
Collaborators:Bar-Server, Ichiro Fukumori, L.-L. Fu (JPL) C. K. Shum, Chan Yi (Ohio State Univ.)Geoff Blewitt (Nevada)
Y. Tony SongJet Propulsion Laboratory
2
Who parted the Red Sea? Tsunamis (Walter Munk 2000).
Historical Tsunamis
The first recorded, the Aegean Sea tsunami in 426 B.C. by Greek historian Thucydides (460 – 400 B.C.), who linked it to an earthquake.
Tony Song, Jan 2012
3
Date Location Magnitude Early Warning? Fatality
26 Dec 2004 Sumatra 9.2 No warning Tsunami death~230,000
28 Mar 2005
19 July 2005
Nias Island
North California
8.7
7.7
Panic evacuation
False alarm
Evacuation killed ~100
No tsunami
27 Jan 2006
3 May 2006
19 July 2006
15 Nov 2006
Benda Sea
Tonga
South Java
Kuril Islands
7.6
8.0
7.7
8.3
No warning
Panic warning
No warning
False alarm/alert
No tsunami
No tsunami
Tsunami death~730
Small tsunami
13 Jan 2007
1 Apr 2007
15 Aug 2007
12 Sep 2007
Kuril Islands
Solomon Island
Central Peru
South Sumatra
8.1
8.0
8.0
8.4
False alarm/alert
Alert
Alert
Alert
No tsunami
Tsunami death~54
No tsunami
No tsunami
…
27 Feb 20100
25 Oct 2010
Chile
Sumatra
8,8
7.7
Basin-wide Warning
No warning
Casualty? (relative small)
Tsunami death~100
11 Mar 2011 Tohoku-Oki, Japan
9.0 Basin-wide Warning Tsunami death ~19,000
Recent Tsunamis
Tsunami occurs quite often—the most devastating disaster
Tony Song, Jan 2012
4
Tsunami Characteristics
• Tsunami speed: 800 km/hour (jet plane speed)
• Wave length: ~ 200 km• Wave height: 20 cm ~ 10 m+• Reaches shore: 20~30 minutes after an earthquake
ghc
Tony Song, Jan 2012
5
Tsunami is predictable
because its pre-cursor (earthquake) can be detected earlier.
Potential Tsunamis
Tony Song, Jan 2012
6
Zhang Heng ( 張衡 , 78 – 139 A.D.) was an astronomer, mathematician, and poet of the Eastern Han Dynasty in ancient China. He invented the first seismograph in 132 A.D.
“Refusing to accept superstitious explanation of the earthquakes, Zhang made heroic observations of earthquakes and invented the ‘Didong Yi’ to detect earthquake from distance”
Earthquake Detection
Horizontal pendulum seismograph invented by English seismologist John Milne in1880.
Caltech Prof. Charles Richter invented the Richter’s scale of earthquake in 1935.
7
Earthquake-Magnitude-Based Tsunami Warnings(NOAA’s PTWC)
Unfortunately, 1.earthquake magnitude is not a good indicator of a resulting tsunami;2.DART system was not designed for early warnings.
Current Tsunami Warning System
Tony Song, Jan 2012
8
Example 1: The 2004 Sumatra M9.2 earthquake and Tsunami
Has the earthquake-magnitude-based approach worked ?
Let’s see the fact
Fact:•About 230,000 people died due to the tsunami.
•Initial estimate of the EQ M8.2 was incorrect (too small).
•No tsunami warning was issued.
Tony Song, Jan 2012
December 2004
9
Example 2: The 2010 Chilean M8.8 Eq and Tsunami
February 2010
CNN reporting, 27 Feb, 2010
Fact
•Initial estimate of the EQ M8.8 was correct.
•A basin-wide tsunami warning was issued, and some costal communities in Hawaii and Japan were evacuated.
•However, no damaging tsunamis observed in those far-field regions.
Tony Song, Jan 2012
10
Example 3: The 2011 Japan M9.0 Eq and Tsunami
March 2011
Fact:
•Initial estimate of the EQ M8.0 was incorrect.
•Tsunami warning was issued.
•Still, about 20,000 people died due to the tsunami.
•“Had the magnitude been correctly estimated initially, more lives could have been saved “ [Ando et al. 2011].
Summary: Earthquake magnitude is not a good indicator of a resulting tsunami.
Tony Song, Jan 2012
11
A New Tsunami Theory
Energy approach—Potential energy and Kinetic energy
Lateral motions of continental slopes transfer the major tsunami energy
Song et al., The role of the horizontal impulses of the faulting continental slope Song et al., The role of the horizontal impulses of the faulting continental slope in generating the 26 December 2004 tsunami,in generating the 26 December 2004 tsunami, Ocean Modell. Ocean Modell. [2008].[2008].
Tony Song, April 2010
Courtesy Chen Ji
12
Grace
Seafloor uplift
TOPEX/Poseidon
Sea Surface Height
Launched 2002
Evidence from satellitesVertical uplift was not the only cause of the 2004 tsunami
(Song & Han 2011)
Tony Song, April 2010
Song, Y.T. and S.-C. Han (2011)Song, Y.T. and S.-C. Han (2011)
13
A New Tsunami Detection Approach
Song, Y.T., Detecting tsunami genesis and scales directly from Song, Y.T., Detecting tsunami genesis and scales directly from coastal GPS stations, GRL, 34, (2007).coastal GPS stations, GRL, 34, (2007).
Tony Song, April 2010
14
A Pilot NASA Project
GPS-aided Real-Time Earthquake and Tsunami (GREAT) Alert System
Team LeaderTeam Leader: Yoaz Bar-Sever (JPL): Yoaz Bar-Sever (JPL)
JPL/ NASA JPL/ NASA Richard Gross, Tony Song, Frank WebbRichard Gross, Tony Song, Frank WebbPacific Tsunami Warning Centre / NOAA Pacific Tsunami Warning Centre / NOAA Vindell HsuVindell HsuUSGS USGS Kenneth HudnutKenneth HudnutUniversity of Nevada Reno University of Nevada Reno Geoff Blewitt, Hans-Peter PlagGeoff Blewitt, Hans-Peter PlagCalifornia Institute of Technology California Institute of Technology Mark SimonsMark Simons
Tony Song, April 2010
15
Real-Time Test 1:Chile M8.8 Earthquake Demonstrates GPS method
(a): NASA's Global Differential GPS (GDGPS) measures the Chile M8.8 earthquake displacement in real time at Santiago.
(b): JPL team predicts a moderate sized tsunami using the real-time GPS and the Song tsunami generation model.
(c): NASA/CNES satellites Jason-1 and Jason-2 confirm the tsunami amplitude of the GPS-based model prediction.
Next steps: Strengthen real time GDGPS network, automate models.
Tony Song , Yoaz Bar-Sever, et al /JPL
Tony Song, April 2010
16 Tony Song, April 2011
ARIA/JPL
Test 2 (after event):2011 Tohoku-Oki M9.0 Earthquake & Tsunami
GPS-based Tsunami Prediction System
Song, et al., GRL, 2012Song, et al., GRL, 2012
17
Matching Models With Satellite Data
Tony Song, Dec 2011
Model simulation of the March 11, 2011 tsunami, generated Model simulation of the March 11, 2011 tsunami, generated from 1,200 GPS offset data and synchronized with actual from 1,200 GPS offset data and synchronized with actual
satellite tracks (Jason-1 and Jason-2).satellite tracks (Jason-1 and Jason-2).
18
Matching Models With Satellite Data
Tony Song, Dec 2011
NASA’s Jason-1 satellite was at the right place at the right time and observed the merged waves
Track1 observedtsunami height ~30 cm
Track2 observedtsunami height ~70 cm
Track3 observedtsunami height ~30 cm
DataModel
19
Detect Tsunami Scales
10log10 TT ES
Earthquake Magnitude Tsunami Energy(ET)
Tsunami Scale(ST)
Basin-wide Warning?
GPS Seismic GPS Seismic ST = 5 threshold
2004 Sumatra (Mw 9.2) 6.0e+15 J 5.2e+15 J 5.8 5.7 >> 5 Yes
1964 Alaska (Mw 9.2) 8.2e+15 J 5.9 >> 5 Yes
2005 Nias Island (Mw 8.7) 2.8e+14 J 2.2e+14 J 4.4 4.3 << 5
2009 Samoa (Mw 8.0) 3.5e+14 J 4.5 << 5
2010 Chile (Mw 8.8) 6.5e+14 J 4.8 << 5
2011 Tohoku-Oki (Mw9.0) 3.0e+15J 5.5 >> 5 yes
Tony Song, June 2011
Procedure:
• Collect GPS displacement in real time
• Model the seafloor motions
• Estimate Tsunami Energy/Tsunami Scale (Song 2007):
20
Summary
GPS Detection of Tsunami Scales for Early Warnings
1. We have developed an innovative approach to detect the triggers of tsunamis and tsunami scales using real-time GPS network.
2. Based on the new approach, we have successfully tested some GPS stations on the 2010 Chilean tsunami and 2011 Japanese tsunami.
Tony Song, Jan 2012
21
The Good NewsGPS detection tsunamis was ranked as Top 100
Science Stories of 2010
Katerva identifies the best ideas on the planet and accelerates themtoward impact at the global level.http://katerva.org/the-katerva-awards
Tsunami Detection, nominated, entered finalist, then runner up for the 2011 Katerva Award in Human Development category
Tony Song, Jan 2012
22
• Need NASA, NOAA, USGS, academic, and Industry collaborations to develop a universal data system ( working with Chile, China, Japan, GDGPS).
• Need an automation system to response earthquakes and tsunamis (developing at JPL).
• Need more research on tsunami genesis.
Tony Song, Jan 2012
The Bad News
Many challenges ahead
23
Two Implications
Tony Song, Dec 2011
Near-field forecast:Near-field forecast: Coastal GPS is a solution. Coastal GPS is a solution. For example, the initial seismic estimate of the March 11, 2011 earthquake was significantly smaller. Had the magnitude been correctly estimated initially, more lives could have been saved [Ando et al. 2011].
Far-field Forecast: No large-scale panic is necessary, but need to identify those regions in the direction of the merging tsunamis (which are predictable).
24
Project 2, NASA Decision $1.1M: GPS-aided Real-Time Earthquake and Tsunami (GREAT) Alert System
JPL (Bar-Sever, Gross, Song, Webb)USGU (Hudnut)NOAA’s PTWC (Hsu) Caltech (Simons) UNR (Blewitt, Plag)
Tony Song, May 2008
Existing GDGPS (JPL/NASA)
Add into GDGPS
Project 1, JPL R&TD $150K: Demonstrating a Coastal GPS Network for Directly Detecting Tsunami Genesis and Scales
On Going Tsunami Research(Needs multi-disciplinary effort: Seismology, Oceanography, GPS technology, and Computing)
Project 3, NASA Disasters Program $150K: GPS-aided and DART-ensured tsunami detection system.
25
A Global GPS Network GPS-Aided Tsunami Early Detection (GATED) System
Tony Song, Dec 2011