COCONet: An Opportunity for Strengthening Disaster Risk Reduction in the Eastern Caribbean LLOYD LYNCH Seismic Research Centre University of the West Indies St. Augustine Trinidad and Tobago LLOYD LYNCH Seismic Research Centre University of the West Indies St. Augustine Trinidad and Tobago 2011 COCONet Network June 28-29, COCONet Network June 28-29, 2011

Selected Disastrous Geologic Events in the Caribbean in the Last 110 years EventDateCountryFatalitiesNo AffectedDamage Volcanic Eruption08/05/1902Martinique30000 Volcanic Eruption08/05/1902St. Vincent1670 Earthquake14/01/1907Jamaica2000 Earthquake25/05/1972Nicaragua Earthquake08/10/1974Antigua/Barbuda Earthquake29/05/1976Guatemala Earthquake/Tsu4,8/08/1946Dom Rep1700? Volcanic Eruption07/06/1985Colombia Earthquake07/06/1985Mexico Earthquake08/06/1986El Salvador Pacific Tsunami14/06/1992Nicaragua Volcanic Eruption19/07/1995Montserrat Earthquake21/06/1999Colombia1,185559,4011,580 Earthquakes23/06/2001El Salvador Earthquake12/01/2010Haiti Sources:EM-DAT/OFDA/CRED/ECLAC/IDB

“The number of attempts to synthesize the tectonic framework of the Caribbean are infinite as are the number of different frameworks that have been suggested….In terms of the plate tectonic revolution in earth science it would be very much preferable if the Caribbean area and the Bahamas did not exist.” Quote from F. Nagle, Caribbean Geology, Bulletin Mar., Sci, 1970

Caribbean Geodynamics Setting [after, e.g., Jordan, 1975; Adamek et al., 1988; Holcombe et al., 1990; Mascle and Letouzey, 1990; Pindell and Barrett, 1990; Heubeck and Mann, 1991; Mann et al., 1995; Flinch et al., 1999; Weber et al., 2001]. Bathymetry from Smith and Sandwell [1997]. Subduction rates from DeMets et al. [2000] and Weber et al. [2001].

The Quill, St. Eustatius The Bottom, Saba Mt St. Catherine, Grenada Kick ‘em Jenny The Soufriere, St. Vincent Sulphur Springs, St Lucia Montagne Pelee, Martinique Morne Aux Diables, Dominica Volcanoes of the Eastern Caribbean La Soufriere, Guadeloupe Soufriere Hills, Montserrat Nevis Peak, Nevis Mt. Liamuiga, St. Kitts

Existing seismic stations that are already contributing and regional stations that could potentially contribute to CTEWS – Global View, 207 Stations Subset of Intermediate Period and Broadband Instruments in Caribbean and adjacent Regions (2008)

Caribbean earthquakes 1 Historical

Seismic Research Unit The University of the West Indies St. Augustine Trinidad Tel Fax Caribbean earthquakes The instrumental Period This slide shows earthquakes since Note that although there is far greater detail, the general pattern is the same

Plate Dynamics in the Eastern Caribbean Oblique Collision Transpression

Eastern Caribbean seismicity p.72

Eastern Caribbean Earthquake Statistics Expected Frequency based on 2009 study of boxed area (12-14 N)

Seismotectonic Source Zones along the eastern Boundary of the Caribbean Plate

EC Eqs. with M>5.9 ( ) and PGA Hazard Map (RP=475 yrs)

2009 Revision of East. Caribbean Hazard Maps depicting Spectral Acceleration at 0.2 and 1.0sec for Return Period of 2475 years

Map of Stations Contributing Data to the Tsunami Warning Network us.php?maptype=1&stat_type=100

Eastern Caribbean Broadband Stations Total = 32 Stns V VSAT Comms V V V V V V V V V V Planned VSAT Stns Planned Internet Stns

Surface elevations for the Lesser Antilles Scenario (in source region which produced M event)

Moment Tensor Solutions Used in the definition of sources

Generalised structure map of the Southern Caribbean (After Pindell et al 2007)

Tectonic setting of Trinidad showing results of previous GPS studies (with stable S. America as a reference frame). Green vectors from Perez et al. (2001); orange vectors from Trenkamp et al. (2002); blue vectors from Weber et al. (2001). [After Soto et al] Tectonic setting of Trinidad

shortening and overthrusting, Arc-parallel extension. Transition zone After FEUILLET ET AL.

Key Considerations In the Eastern Caribbean, several populated centres are (may be) threatened by near –surface, potentially active faults GPS has the potential to identify such faults and help is assessing the contribution to earthquake hazard. Population centres are also threatened by large subduction earthquakes Study of the distribution of strain rate through GPS could help to resolve uncertainty of the earthquake source parameters. The Eastern Caribbean is at risk from “short fused” tsunamis an subsidence surge GPS could add another dimension to the Coastal Hazard and Tsunami Early Warning System More than 300,000 West Indians live and/or work along the flanks of live volcanoes. GPS is currently used to develop and maintain a database of flank elevation Key Considerations In the Eastern Caribbean, several populated centres are (may be) threatened by near –surface, potentially active faults GPS has the potential to identify such faults and help is assessing the contribution to earthquake hazard. Population centres are also threatened by large subduction earthquakes Study of the distribution of strain rate through GPS could help to resolve uncertainty of the earthquake source parameters. The Eastern Caribbean is at risk from “short fused” tsunamis an subsidence surge GPS could add another dimension to the Coastal Hazard and Tsunami Early Warning System More than 300,000 West Indians live and/or work along the flanks of live volcanoes. GPS is currently used to develop and maintain a database of flank elevation

TYPICAL SRC ISLAND NETWORKS Example 1: DOMINICA Installed 3 cGPS (red stars) at DOMI, ROSS & PNVL Total of 15 benchmarks (red dots) periodically measured. Measurement interval ~ 2 hrs Recording rate ~ 1 sec

Morne Aux Diables - N. Dominica Since June 2009 to present, there has been elevated seismic activity or ‘seismic unrest’ beneath Morne Aux Diables. GPS surveys have been more frequent, in February 2010 & again in October Networks utilized ROSS &PNVL as base stations and benchmarks measured ~ 2 hrs. So far, results highlight no clear changes in co-ordinate location or baseline length.

Typical GPS benchmarks are: 1/ 10 cm long pins 2/ 15 cm metal screw-threaded rods Both types drilled & epoxied onto concrete roofs Eg THBD pin at Thibaud village (on Health Centre roof)

Morne Aux Diables complex from Morne Diablotins

SRC GPS Network SRC, OSVG and OSVM operate and share a growing Network of cGPS stations in the eastern Caribbean (currently 11 stations). Files are sampled at 1 hz and FTPed in hourly files to servers for redistribution to the wider community of stakeholders. SRC uses the network primarily for referencing for the campaigns of volcano deformation networks but as the network grows it is increasingly providing more insights on regional plate dynamics.

Eastern Caribbean cGPS Stations

2007 GPS Time Series - ALBI, Antigua SVGB, St. Vincent & ANTG, Antigua ANTG SVGB ALBI

Priorities/Goals Reduce Downtime; Expand the network; Characterize and reduce noise; Add redundancy; Improve latency; Improve overall quality of next generation stations, particularly stability of site/monument; Improve data archiving/processing infrastructure; Establish QQ regime and visualization tools; Integrate into EW Systems; Bootstrap research program. Priorities/Goals Reduce Downtime; Expand the network; Characterize and reduce noise; Add redundancy; Improve latency; Improve overall quality of next generation stations, particularly stability of site/monument; Improve data archiving/processing infrastructure; Establish QQ regime and visualization tools; Integrate into EW Systems; Bootstrap research program.

Station Siting St BartsvE AnguillaN* St KittsvE St. MarteenE* RedondaNP MontserratvPF AntiguavERF* BarbudavNS* GuadeloupevE* Dominica (2)vE, NF* Martinique (4)vE*,vNF** St. LuciavNF* St. Vincent (2)vE* BarbadosvE* MustiqueNF CarriacouvNF* GrenadavE* Tobago (2)vE, E* Trinidad (5)E*, E** Legend V – VSAT Comms E – Existing N – Not in Existence R – To be Refurbished F – Funded Legend V – VSAT Comms E – Existing N – Not in Existence R – To be Refurbished F – Funded