1. The Infrasound Database of the SMDC Monitoring Research Program J
The Infrasound Database of the SMDC Monitoring Research Program J. Roger Bowman, Gordon Shields, Michael S. O’Brien and Hans Israelsson Science Applications International Corporation
Presented at the Infrasound Technology Workshop Tokyo, Japan November 13-16, Approved for public release; distribution unlimited   DISCLAIMER “The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either express or implied, of the U.S. Army Space and Missile Defense Command or the U.S. Government.”

2. Outline Introduction Events Signals Waveforms Station metadata
Establishing ground truth
Examples of ground truth
Documenting ground truth
Signals
Waveforms
Station metadata
Conclusions 2

3. Introduction What is the Infrasound Database (IDB)? Purpose Focus
Source parameters and their uncertainties
Arrivals (consistent measures of signal features)
Waveforms
Metadata
Purpose
Provide sources and signals suitable for research in detection, feature estimation, location and atmospheric models
in absence of modern recordings of “signal of interest”
Focus
Events with signals similar to “signal of interest”
Events with well constrained source parameters
Plus, other events of general interest 3

4. Events in the Infrasound Database
Available on-line at
278 events as of October, 2007 4

5. Adding Events to the IDB
Media
Web sites
Conference proceedings
Papers
Etc.
Discover events
Compile potential ground truth
Scour the web
Archive all relevant files
Establish ground truth
Assess various sources of “ground truth”
Quantify uncertainties
Document ground truth
Provenance of source parameters and their uncertainties
Measure signal features 5

6. Establishing Ground Truth
Process of determining source parameters and their uncertainties
Not all “ground truth” created equal!
Constraints on source location
Experiment reports (for the rare controlled source)
Location of explosion craters or damaged buildings
Location of volcano craters
Location of open-pit mines
Location of optical signal observed by satellite
Epicenter from seismic bulletin
Eye-witness reports in the media
Estimated from infrasound observations (not ground truth)
Constraints on source origin time
Experiment reports
Near-source acoustic or seismic measurements
Origin time from seismic bulletin
Industrial logs (e.g., mine operators)
Eye-witness reports
Estimated from infrasound observations
Decreasing reliability
Decreasing reliability 6

7. Maputo, Mozambique Arms Depot Explosions
Location: S, E ± 0.6 km
Origin times:
:01 ± 8 min
:33 ± 8 min
:48 ± 8 min
Derived from infrasound arrival times and a range of plausible group velocities
Media reports are vague, inconsistent, and inconsistent with infrasound arrival times
Google Earth
label for armory
Line of sight of
YouTube video 7

8. Videos of Maputo Arms Depot Explosions
First video allows determination of position of camera at airport
Line of sight
Camera operator
Second video allows determination of line of sight to armory relative to airport buildings 8

9. St. Petersburg Gas Pipe Explosion
Pretty picture
Location: N, E ± 0.3 km
Origin time: :02 ± 150 sec
Gas pipeline
From media reports (BBC and Reuters)
No events in IDC REB or NEIC bulletins
Power plant
Lines of sight 9

10. BP Oil Refinery Explosion, Texas, USA
Pretty picture
Location: N, W ± km
Origin time: May :20 ± 60 sec
Plant operations log published in Fatal Accident Investigation Report
No events in IDC REB or NEIC bulletins
Combustible vapor cloud from CFD modeling (Fatal Accident Investigation Report) 10

11. Augustine Volcanic Eruptions, Alaska, USA
Pretty picture
Location: N, W ± km
Origin time: Jan 13 times ± 2 sec
Near-source acoustic onset time
Petersen, T., S. De Angelis, G. Tytgat, and S. McNutt, Local infrasound observations of large ash explosions at Augustine Volcano, Alaska, during January 11–28, 2006, Geophys. Res. Lett., 33, L12303, 2006.
Crater location taken from Google Earth 11

12. Ghislenghien, Belgium Gas Pipe Explosion
Pretty picture
Location: N, E ± km
Origin time: Jul :55:27 ± 2 sec
Correlation of aerial photographs and cultural features in Google Earth
Seismic P and ground-coupled Rayleigh waves
Evers, L. G., L. Ceranna, H. W. Haak, A. Le Pichon, and R. W. Whitaker, A seismoacoustic analysis of the gas-pipeline explosion near Ghislenghien in Belgium, Bull. Seism. Soc. Amer., 97, , 2007. 12

13. Buncefield Fuel Depot Explosion, UK, 2005
Documenting Ground Truth: Event Summaries
Event Summaries standardize the presentation of ground truth information and assessment of its uncertainty.
Example:
Buncefield Fuel Depot Explosion, UK, 2005
Largest peace-time explosion in Europe
British Crown Copyright 2006/MOD
Hyperlinks provide direct access to primary sources of ground truth
Infrasound signals observed at seismic stations1 and included in Infrasound Database
1. Green et al., Infrasound Workshop, Fairbanks, Alaska, September, 2006. 13

14. Documenting Ground Truth: Site Summaries
Site Summaries standardize the presentation of ground truth location and uncertainty for sites of repeated infrasound events. 14

15. Challenges in Establishing Ground Truth
Origin time more difficult than location
Except for controlled explosions
Incomplete reporting
Provenance and uncertainties are often missing
Language
Varying transparency
English version of Russian report using Google Translation
We welcome your help in establishing and documenting ground truth.
Primary sources are cited in the Infrasound Database. 15

16. Infrasound Signal Arrivals
Most events observed on one or several stations
Most propagation paths have been sampled one or a few times
Buncefield, UK Oil Depot Explosion
Powder River,
Wyoming Mines 16

17. Examples of Signal Analysis
Jilin, China petrochemical explosion
13 November 2005
Buncefield, UK oil depot explosion
11 December 2005
Slope of back azimuth and slowness estimated
Treated as single arrival
Treated as multiple arrivals 17

18. Group Velocity First arrival for 455 signals Single mode
No clear distinction between arrivals traveling in stratospheric and thermospheric ducts
Considerable variability of velocity for source-receiver distance < 2000 km
Narrower range for distance >3000 km 18

19. Waveforms Waveform data are available for IDB events for
IMS stations in countries that freely distribute their data or have approved unlimited distribution
Australia, Canada, Germany, the United Kingdom, the United States, territories of these countries, and Antarctica
US research stations (e.g., DLIAR, TXIAR, etc.)
Waveform data are available from the IDC or your country’s NDC for other IMS stations 19

20. Station Metadata
Extensive metadata has been compiled in a standard format for most IMS stations
Summaries available for: I05AU, I07AU, I08BO, I09BR, I10CA, I13CL, I14CL, I17CI, I18DK, I21FR, I22FR, I24FR, I26DE, I30JP, I31KZ, I32KE, I33MG, I34MN, I35NA, I36NZ, I41PY, I52GB, I53US, I55US, I56US, I57US, I59US
Insufficient information available for: I02AR, I04AR, I39PW, I44RU, I46RU, I47ZA, I48TN, I49GB, I50GB 20

21. Conclusions Infrasound database Cooperation requested
Has 278 events relevant to research in detection, characterization and location of infrasound “events of interest”
Has carefully assessed and documented source parameters and uncertainties
Is available on-line at
Cooperation requested
Share references to ground truth in your regions of interest
Document source parameters in presentations and papers
Organize and share station metadata for use by the infrasound community 21

22. Videos of Infrasound Sources
Henderson, Nevada rocket fuel factory (PEPCON) explosion (USA) 1988 May 4
Kolding fireworks factory explosion (Denmark) 2004 Nov 03
Mt. Augustine, Alaska volcanic eruption (USA) 2006 January
Maputo arms depot explosion (Mozambique) 2007 Mar 22
St. Petersberg gas pipeline explosion (Russia) 2007 Jul 26 22