Seismic Hazard Assessment Study for Seismic Hazard Assessment Study for the Eastern Caribbean Islands the Eastern Caribbean Islands
Carlo G. Lai
Francesca Bozzoni Mirko CoriglianoLaura Scandella Elisa Zuccolo
Walter Salazar
Richard RobertsonLloyd LynchJoan Latchman
Trinidad, 26 May 2010
Outline
Critical Review of the Past Seismic Hazard Assessment StudiesThe Studied Area
Probabilistic Seismic Hazard Analysis (PSHA)Methods of calculation
- Classical Cornell-McGuire approach- Zone-free approach by Woo (1996)
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Construction of the Earthquake CatalogueIdentification of Seismic Zones
Attenuation RelationshipsProcessing of the Catalogue
- Zone-free approach by Woo (1996)
PSHA analysis and resultsCompatibility with IBC 2009/ASCE 7-05
Influence of seismogenic zoneVertical component
Practical application
Probabilistic Seismic Hazard Analysis Probabilistic Seismic Hazard Analysis (PSHA)(PSHA)
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Identification of Identification of seismogenicseismogenic zoneszones(Cornell(Cornell--McGuire approach)McGuire approach)
Definition of Seismogenic Sources
WE NEED TO SEPARATE THE WE NEED TO SEPARATE THE EVENTS LISTED IN THE
CATALOGUE IN SEISMOGENIC ZONES ACCORDING TO THE
TECTONIC-GEOLOGICAL INFORMATION
Used instruments
In-depth investigation of the scientific publications regarding the seismotectonic setting of the Eastern Caribbean region
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Analysis of transversal sections
Compatibility analyses between the proposed seismic delimitation and the Catalogue events using ArcGIS
General seismo-tectonic setting
Subduction
VOLC
TransformFaults and
Subduction
Transitions
Jordan, 1975
SubductionCANOES
Subduction
Transitions
(60-61 W)
Trasversal section
0
7 9 11 13 15 17 19 21Lat (km)USGS/PDE (1973-2009)
Transversal section
Upper Crustal seismicity and
inter and intra-plate
subduction seismicity
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-250
-200
-150
-100
-50
0
Dep (km)
Seismogenic sources
Proposed geometric delimitation
• Zone 1: Volcanic Island-arc.• Zone 2-5: Subduction in the Lesser-
Antilles.
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Antilles.• Zones 6-8: Puerto Rico and Virgin
Islands.• Transition Zones 9 and 10A.• Zone 10B: East of Trinidad.• Zone 11: North of Paria Peninsula.• Zone 12: Trinidad Faults.• Zones 13 and 14: El Pilar fault. • Zone 15: South of Trinidad.
Zone 1: Volcanic Island-arc.
• The upper-crustal seismicity concentrates within theupper 35 km of the Caribbean continental plate in theLesser Antilles Arc (Boynton et al. 1987), with epicentersplotting from the island of Martinique to Anguilla within anearly continuous belt of 100 km width along both, theaxis of the principal active volcanoes and the inland and
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axis of the principal active volcanoes and the inland andoffshore shallow faults which run parallel to theSubduction Trench.
• Within this zone the magnitudes are moderate, reachinga maximum value of about 6.6 through historic times
Bengoubou-Valerius (2008):
- Oceanic trench;
- Limit low/high seismicity along the arc (“We have been able to confirm a
Transversal sections
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arc (“We have been able to confirm a progressive increase of seismic activity from south to north between Martinique and Antigua”).
Transversal Sections
Upper Crustal seismicity inter and intra-plate subduction seismicity
1111
Bengoubou-Valerius (2008)
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(Byrne, Davis and Sykes, 1988)
(McCann, 1985)
Interface and Intraplate subduction
and
Volcanic island arc seismicity
Zone 1: Volcanic Island-arc.
• Bernard & Lambert (1988) suggested that the evaluation ofseismic hazard must also take into account these shallow-moderate earthquakes as the ones occurred on 1851 and1897 in Guadeloupe (~5.5-6.0 Mw), March 16th 1985 (6.4M ) at South of Nevis, and the event occurred on
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Mw) at South of Nevis, and the event occurred onNovember 21st 2004 with a magnitude of 6.3 (Mw) in theNorth-West of Dominique near the Les Saintes Islands.
• The fault plane solutions in this zone yield both, normaland strike-slip focal mechanisms.
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McCann (1985):
- position of Volcanic Arc
- dimension of Volcanic Arc;
The moderate shallow earthquakes do not necessarily occur in conjunction with
volcanic eruptions and frequently appears in clusters with no discernible mainshock
(swarms)
Zone 2-5: Subduction in the Lesser-Antilles.
• The volcanic island-arc lays about 300 km from the EasternCaribbean Trench, where the North American plate begins tosubmerge underneath the Caribbean plate reaching depths of 200km below the islands generating earthquakes as large of magnitude8.0 Mw. We include in Zones 2 and 3 all the shallow focusearthquakes (depth ≤ 50 km) along the inclined inter-face seismic
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earthquakes (depth ≤ 50 km) along the inclined inter-face seismiczone that yields underthrust focal mechanisms (Byrne et al. 1988).
• Convergence between the Caribbean and North American platesoccurs at a rate of about 37 mm/yr (Sykes et al., 1982; McCann1985). The focal mechanisms of deeper intra-plate events (>50 km)indicate that there is a normal faulting resulting from initial flexure ofthe down going Atlantic slab (Zone 4 and 5) with an average ofwestward dipping angle of 50º (Bengoubou-Valeruis et al, 2008).
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Trasversal section
0
-67 -65 -63 -61 -59 -57Long (km)USGS/PDE (1973-2009)
Transversal section
Upper Crustal seismicity and
inter and intra-plate
subduction seismicity
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(12-14 N)
-250
-200
-150
-100
-50
0
Dep (km)
Zone 2 and 4 cover the latitudes from 14.8ºN to 20.0ºN and it is characterized witha higher seismic activity than Zone 3 and 5 (from 11.0ºN to 14.8ºN latitude).Bengoubou-Valeruis et al. (2008) and Russo et al. (1993) attributes thedifferences of the seismic activity to the following reasons:
• a) changes in the tectonic structures mapped by Feuillet et al. (2002);
• b) enough sediments to lubricate or decouple the two plates in the Subduction
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• b) enough sediments to lubricate or decouple the two plates in the SubductionZone;
• c) strengthening caused by thick accretionary prism overbudden which liesabove the shallow reach of the subduction zone; the quiescent area coincideswith the deepest part of the Barbados accretionary wedge. The upper-crustalseismic activity level observed along the volcanic-island arc reflects also thedifferences observed in the seismic activity in the Subduction Zone.
• The Puerto Rico and the Virgin Islands region isconsidered as a microplate that is surrounded by theobliquely subducting North America plate, the Caribbeanplate and several major faults as the Mona Canyon tothe East and Abnegada Passage to the West (McCann,
•
Zones 6-8: Puerto Rico and Virgin Islands.
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the East and Abnegada Passage to the West (McCann,1985, Jansma et al. 2000) and the Muertos Trough tothe South.
• Puerto Rico accommodates approximately 16.9 mm/yr ofdeformation relative to North America and 2.4 mm/yrrelative to the Carribbean Plate (Clinton et al., 2006).
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Clinton et al. (1996)
• Zone 6. This zones includes the Puerto Rico Trench areawithin depth less than 50 km including the megathurstfaulting along the plate interface of the subducting NorthAmerican Plate southward deepening.
• Also this zone comprises the left lateral strike slip faulting
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that is subparallel to the Puerto Rico trench North andNorth-West of Puerto Rico including the Septentrionalfault.
(17-18 N)Trasversal section
0
-67 -65 -63 -61 -59 -57Long (km)USGS/PDE (1973-2009)
Transversal section
Crustal seismicity, interface and intra-
plate seismicity
2222
-250
-200
-150
-100
-50
0
Dep (km)
(Z6)
(Z8)
2323
(McCann, 1985)
(Z7)(Z7)
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• Zone 7. This zone comprises the shallow faults (less than 50 km depth) inland Puerto Rico and offshore namely, Mona Canyon, South Lajas Fault, Great Northern and Southern Puerto Rico fault zone, the Anegada Trough and Sombrero Seismic Zone (Clinton et al., 2006).
• This seismogenic source has produced yielding normal
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• This seismogenic source has produced yielding normal faulting in a broad zone of active crustal extension and accompanied by destructive tsunamis (Mueller et al., 2003). The absence of volcanism in Puerto Rico and the Virgin Islands suggests that this zone is not an extension of the island-arc Lesser Antilles structure (Molnar & Sykes, 1969).
• Zone 8. This zone includes the intra-plate subductionseismicity generated mainly the bending of North-American slab with depth greater than 50 km.
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2727
Right Lateral
Normal Faulting
Transition Zones 9 and 10A.• We define these seismogenic zones as the intersections amongst
the transform faults and subduction zones with the Lesser AntillesArc located at the North and the South of the Eastern Caribbean.Zone 10A includes the shallow seismic activity in the South part ofthe island of Tobago which we consider within the Caribbean-SouthAmerican plate boundary (Latchman 2009, Weber, 2009 and
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American plate boundary (Latchman 2009, Weber, 2009 andBurmester et al 1996). Moderate but shallow earthquakes occurredwith right-lateral strike slip and normal faulting mechanism,respectively (Morgan et al., 1988; Latchman 2009).
• The transition Zone 9 is characterized by a low-seismicity level inthe boundary zone between the Lesser Antilles arc and the PuertoRico Trench yielding mainly normal focal mechanisms.
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Zone 10B: East of Trinidad.
• Russo & Speed (1992) suggested that the earthquakeslocated in this zone are consistent with the detachmentand bending-flexure of the South American slab movingtoward the collision zone.
3030
• The zone covers mainly normal faulting mechanism withENE-WSW striking planes and strike slip faults with anaverage depth of 45 km.
3131
(Russo et al., 1993)
Trasversal section
-67 -65 -63 -61 -59 -57Long (km)
USGS/PDE (1973-2009)
Transversal section
Crustal seismicity and intra-plate
seismicity
3232
(10-11 N)-250
-200
-150
-100
-50
0
-67 -65 -63 -61 -59 -57
Dep (km)
Zone 11: North of Paria Peninsula• This zone constitutes a subducting detached oceanic
lithosphere with depth ranging from 50 to 300 km andrepresents one of the most active seismogenicsources in the Eastern Caribbean (Russo et al. 1993;SRC, 2009b).
3333
• The focal mechanisms indicate that there is a normalfaulting resulting from the initial flexure of the downgoing slab with a steeply NW-dipping of 60º. However,mixed-motion earthquakes with thrust and strike slipindicated bending of the subducting slab at deeperdepths.
TRINIDAD
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Weber et al
(2009)
Zone 12: Trinidad Faults.• Regional tectonic-geological studies conclude that el Pilar Fault
might right-step into Central Trinidad (i.e. Flinch et al., 2000),however, Weber (2001, 2009) affirms that the N68ºE oblique trendingin the Central Range Fault is not associated with el Pilar Fault 90ºtrending of pure wrenching.
3535
• The Northern Range and the Arima Fault comprises a complex faultsystem with lateral strike-slip, thrust and normal faulting. OnDecember 2nd and 3rd 2004 events with a magnitude of 5.8 and 5.4(Mw) occurred in the central north-east of Trinidad; fault planesolutions suggest mainly a normal motion with a component of right-lateral strike slip. The location of these earthquakes and thecorrespondent focal mechanisms coincides with the Northern Rangenormal fault dipping southward mapped by Algar & Pindell (1993)beneath the Caroni Swamp area.
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Zones 13 and 14: El Pilar fault. • These zones comprise the boundary between the Caribbean and the
South American plate. The events that have their origin in the fault areshallow - less that 50 km depth - and they are characterized mainly byright lateral strike slip mechanism in the northern coast of SouthAmerica. The Caribbean Plate is moving about 20 mm/yr in an easterlydirection relative to South America (Perez et al. 2001).
3737
direction relative to South America (Perez et al. 2001).
• However, thrust focal mechanism also takes place in this regionreflecting the oblique collision at crustal levels between the Caribbeanand the South American Plate. We observed a high level seismicoutput in Zone 14 that extends from 63.5º W to 62.3ºW longitudecovering the Araya-Paria Isthmus, and a moderate seismicity level inZone 15 that extends from 67.0º to 63.5º W longitude covering thevicinity of Caracas to the Araya region.
Zone 15: South of Trinidad.
• Russo et al. (1993) defined this zone as a passivemargin edge in the Foreland basin in North ofSouth America continent, covering events withstrike slip, mixed thrust and strike slip, and thrust
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strike slip, mixed thrust and strike slip, and thrustmechanism around the Orinoco-Delta region inVenezuela, with an average depth of 50 km and amaximum magnitude of 6.6 (Mw).
Main characteristics of the seismic zones Depth (km) Type Main Focal Mechanism
ZONE 1 19.1 Upper-crustal Normal and Strike-Slip
ZONE 2 29.6 Interface Thrust (Inverse)
ZONE 3 29.4 Interface Thrust (Inverse)
ZONE 4 86.0 Intraplate Normal
ZONE 5 97.9 Intraplate Normal
ZONE 6 32.3 Interface Thrust and Strike-Slip
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ZONE 6 32.3 Interface Thrust and Strike-Slip
ZONE 7 28.4 Shallow Normal
ZONE 8 74.5 Intraplate Normal
ZONE 9 24.4 Transition Normal and Strike-Slip
ZONE 10 43.9 Transition/Intraplate Normal and Strike-Slip
ZONE 11 99.5 Intraplate Normal
ZONE 12 32.5 Crustal Normal and Strike-Slip
ZONE 13 23.3 Crustal Strike slip and Thrust
ZONE 14 14.7 Crustal Strike slip and Thrust
ZONE 15 57.3 Crustal Strike slip and Thrust
Seismogenic sources with events
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Ground Motion Prediction Equations (GMPEs)Ground Motion Prediction Equations (GMPEs)
4141
Ground Motion Prediction Equations (GMPEs)Ground Motion Prediction Equations (GMPEs)
• GROUND MOTION PREDICTION EQUATIONS (GMPEs)
• Log y = a + b M + c log R + d R + s + sigma
SOURCE PATH SITE
4242
SOURCE PATH SITE
y : ACCELERATION, M: MAGNITUDE, R: DISTANCE
a,b,c,d,s and sigma: regression analysis
4343
Analyzed GMPEs
SUBDUCTION ZONES:
� Youngs et al. (1997)� Atkinson and Boore (2003-2008)� Zhao et al. (2006)� Kanno et al. (2006)� Lin and Lee (2008)
4444
� Lin and Lee (2008)
CRUSTAL ZONES:
� Kanno et al. (2006)� Zhao et al. (2006)� Abrahamson and Silva (2008)� Boore and Atkinson (2008)� Campbel and Bozogornia (2008)� Chiou and Youngs (2008)
VOLCANIC ZONE:
� Sadigh et al. (1997)� Salazar (2004)� Zhao et al. (2006)� Kanno et al. (2006)� McVerry et al. (2006)� Abrahamson and Silva (2008)� Chiou and Youngs (2008)
El Salvador
New Zealand
• We corrected the acceleration time histories using a base-line correction, a band pass filter and perform the integration in the frequency domain yielding the velocity and displacement yielding the velocity and displacement postscript plots. The correspondent Fourier and Response Spectra for 5% damping are also reproduced in this scheme.
4545
Comparison of GMPEs with available data• Seismic Research Centre (SRC)
• BRGM (Bureau de Recherches
Géologiques et Minières - France)Date Mw H
Earthquaketype
Lat. Long.
November 29, 2007 7.4 148.0 intraplate 14.97 -61.26
October 4, 2000 6.1 110.4 intraplate 11.16 -62.29
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October 4, 2000 6.1 110.4 intraplate 11.16 -62.29
October 28, 2005 5.5 80.9 intraplate 11.11 -62.04
November 15, 2006 5.2 98.9 intraplate 10.78 -62.65
October 24, 2005 5.1 137.7 intraplate 11.10 -62.39
November 17, 2006 4.9 135.8 intraplate 11.39 -62.24
January 25, 2001 4.6 85.5 intraplate 10.70 -62.57
June 8, 1999 5.8 52.4 interface 15.07 -60.40
December 2, 2004 5.8 48.2 crustal 10.49 -61.45
December 3, 2004 5.4 40.5 crustal 10.54 -61.46
June 21, 2003 5.3 10.0 crustal 10.79 -59.27
November 21, 2004 6.3 21.2Volcanic island arc
15.73 -61.68
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• DISTANCE P G A (cm/s/s)
• st yy mm dd hh mi sec lat lon depth Mw Epic. Hy po. N-S E-W UD slat slon ele. stype filename
• km km km m
• INTERFACE EARTHQUAKE
• GADA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 177.06 184.65 9.8447 15.7043 6.3001 16.2356 -61.5309 15 B0.0 1999.06.08-12.04.13.GADA
• GBRA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 177.62 185.19 2.9142 3.0210 1.4393 16.2556 -61.5162 10 R 1999.06.08-12.02.99.GBRA
• GCCA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 180.49 187.94 3.8948 3.4213 1.6637 16.2768 -61.5319 5 S 1999.06.08-12.04.13.GCCA
• GFEA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 177.81 185.37 7.9028 6.7112 2.5837 16.2395 -61.5369 5 S 1999.06.08-12.04.14.GFEA
• GGSA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 180.33 187.79 11.5927 7.9312 3.9028 16.2662 -61.5417 5 S 1999.06.08-12.04.17.GGSA
• GLAA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 179.28 186.79 1.3991 1.1585 0.8851 16.2495 -61.5460 5 S 1999.06.08-12.03.99.GLAA
• GPAA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 176.63 184.24 2.8366 2.0558 1.3097 16.2330 -61.5279 70 R 1999.06.08-12.04.13.GPAA
• GSPA 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 177.35 184.93 6.1690 3.4603 1.7735 16.2368 -61.5336 5 S 1999.06.08-12.03.99.GSPA
• GT2A 1999 6 8 12 4 0.00 15.07 -60.40 37.0 5 .8 180.62 188.07 12.6054 6.5531 4.5061 16.2694 -61.5421 5 S 1999.06.08-12.04.12.GT2A
• MBRA 1999 6 8 12 4 0.00 15.07 - 60.40 37.0 5.8 89.21 103.47 37.7433 49.9062 34.7575 14.6038 - 61.0773 0 R 1999.06 .08 - 11.56.99.MBRA
ACCELEROMETRIC CATALOGUE
• MBRA 1999 6 8 12 4 0.00 15.07 - 60.40 37.0 5.8 89.21 103.47 37.7433 49.9062 34.7575 14.6038 - 61.0773 0 R 1999.06 .08 - 11.56.99.MBRA
• INTRA PLATE SUBDUCTION
• TPTC 2000 10 4 14 37 50.50 11.16 -62.29 110.4 6. 1 94.85 145.55 58.7540 52.1042 44.2556 10.6800 -61.5700 49 R DQ538
• TWMO 2000 10 4 14 37 50.50 11.16 -62.29 110.4 6. 1 96.38 146.55 59.3524 66.0256 38.4493 10.6700 -61.5600 0 S LZ132
• TBH 2000 10 4 14 37 50.50 11.16 -62.29 110.4 6. 1 153.00 188.67 13.0708 20.9575 7.5213 10.4840 -61.0670 199 R EV019
• INTRA PLATE SUBDUCTION
• ALNG 2001 1 25 4 33 43.00 10.70 -62.57 85.5 4. 6 112.15 141.02 0.4806 0.4959 0.2186 10.1814 -61.6883 0 R CU2150
• TWMO 2001 1 25 4 33 43.00 10.70 -62.57 85.5 4. 6 110.22 139.49 3.8811 3.5447 2.6283 10.6700 -61.5600 0 S ME1391
• TBH 2001 1 25 4 33 43.00 10.70 -62.57 85.5 4. 6 165.73 186.49 0.2265 0.2770 0.1899 10.4840 -61.0670 199 R FA125
• VOLCANIC ARC
• GBRA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 60.90 64.49 47.6633 64.8085 28.9273 16.2556 -61.5162 10 R 2004.11.21-11.40.59.GBRA
• GFEA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 58.58 62.30 84.1276 72.6331 38.1838 16.2395 -61.5369 5 S 2004.11.21-11.38.99.GFEA
• GGSA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 61.32 64.88 98.0630 127.9714 85.7834 16.2662 -61.5417 5 S 2004.11.21-11.41.00.GGSA
• GHMA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 27.95 35.08 217.3862 198.8346 65.6423 15.9808 -61.7035 430 O 2004.11.21-11.42.99.GHMA
• GJYA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 31.59 38.04 201.6058 189.5425 109.8338 16.0136 -61.7046 300 R 2004.11.21-11.41.00.GJYA
• GLAA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 59.41 63.08 119.6347 133.9601 98.2238 16.2495 -61.5460 5 S 2004.11.21-11.40.99.GLAA
• MDIA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 141.47 143.05 7.7459 9.4713 4.6378 14.6099 -61.0499 0 S 2004.11.21-11.41.99.MDIA
• MTHA 2004 11 21 11 41 7.00 15.73 -61.68 21.2 6. 3 140.78 142.37 13.4849 14.9873 8.0515 14.6067 -61.0699 0 S 2004.11.21-11.38.99.MTHA
Adopted GMPEs (subduction zones)Attenuation
EquationApplication
Magnitude definition and
limitations
Distance definition and limitations
Hypocentre depth and limitations Database
Youngs et al.. (1997)
PGA and PSA for 0.075 to 3
s. Horizontal component
Mw ≥ 5
Closest distance to the faulttrace for earthquakes withavailable fault models,otherwise hypocentral distance10 ≤ Rrup ≤ 500 km.
Depth ≤ 50 km for interface eventsDepth > 50 km for inslab events
Developed from a database includingworldwide earthquakes in subductionzones: Alaska, Chile, Cascadia, Japan,Mexico, Peru, Solomon Islands
Atkinson and Boore (2003-
2008)
PGA and PSA for 0.33 to 25
s. Horizontal component
Mw ≥ 5Mw =8.5 for interface events with Mw > 8.5Mw =8 for interface events with Mw > 8
Closest distance to the faulttraceRrup ≤ 400 km.
Depth < 50 km for interface eventsDepth ≥ 50 km for inslab eventsDepth=100 km for events with Depth>100 km
Developed from a database includingthousands of strong motion recordingsfrom events occurring in subductionzones around the world, based on bothCruise (1991) and Youngs et al. (1997)catalogues and added events:Cascadia, Japan, Mexico, CentralAmerica.America.
Zhao et al. (2006)
PGA and PSA for 0.05 to 5 s.
Horizontal component
5.0 ≤ Mw ≤ 8.3
Shorter distance to the rupture zone for earthquakes with
available fault models, otherwise hypocentral distanceRrup ≤ 300 km for slab events
Depth < 25 km for crustal eventsDepth < 50 km for interface eventsDepth ≥ 50 km for inslab eventsDepth =125 km for events with Depth > 125
Developed from the Japanese strongmotion dataset and additional overseasdata from the Western part of US andthe 1978 Tabs, Iran evens to constrainthe near-source behaviour (20 overseasevents of a total of 269 events).This GMPE was used also for thevolcanic zone.
Kanno et al. (2006)
PGA, PGV, PSA for 0.05 to
5 s. Horizontal component
Mw ≥ 5.5
Closest distance to the fault plane for earthquakes with
available fault models, otherwise hypocentral distane
1 ≤ Rrup ≤ 30 km for shallow events
30 ≤ Rrup ≤ 300 km for deep events
Depth ≤ 30 km for shallow eventsDepth > 30 km for deep events
Developed from Japanese seismicwaveform data: earthquake recordsfrom K-NET and KiKnet databases.This GMPE was used also for shallowand volcanic zones.
Lin and Lee (2008)
PGA and PSA for 0.01 to 5 s.
Horizontal component
4.1 ≤ Mw ≤ 6.7 for intraslab events
5.3 ≤ Mw ≤ 8.1 for interface events
Hypocentral distance40 ≤ R ≤ 600 km
for intraslab events20 ≤ R ≤ 300 km
for interface events
Depth ≤ 50 km for interface eventsDepth > 50 km for inslab events
Regional relation based on Chileandata.
Adopted GMPEs (crustal zones)Attenuation Equation Application
Magnitude definition and limitations
Distance definition and limitations
Fault depth definition and contributions to seismic responce
Database
Abrahamson & Silva (2008)
PGA and PSA
for 0.01 to 10 s
Rotation-independent
average horizontal
component
5 ≤ Mw ≤ 8.5Rupture distance0 ≤ Rrup ≤ 200 km
Z_TOR: Depth to the top of the coseismic rupture plane(used in “depth-to-top rupture model” contribution).Z_1.0: Depth to the 1 km/s shear wave velocity horizon(used in “soil-depth” contribution, which is null ifZ_1.0<200 and VS30 ≥ 1000 m/s).In our analysis the hanging wall contribution is notconsidered.If V S30 ≥ 1100 m/s the soil response is assumedlinear for all the periods.
NGA database plus Kocaeliand Chi-Chi mainshocks, ChiChi and Duzce aftershocks.This GMPE was used also forthe volcanic zone.
Campbell &
PGA and PSA
for 0.01 to 10 s.
Mw > 4Mw < 7.5 for normal eventsMw < 8
Closest distance to the surface projection of the coseismic rupture
Z_2.5: Depth to the 2.5 km/s shear wave velocityhorizon (used in “sediments” contribution 0 < Z_2.5 <10 km).If 2 ≤Z_2.5≤ 3, f_sed=0.Z_TOR: Depth to the top of the coseismic rupture plane
Developed from the updatedPEER strong motionCampbell &
Bozorgnia (2008)s.
Horizontal component (geometric
mean)
Mw < 8 for reverse eventsMw < 8.5 for strike-slip events
the coseismic rupture plane0 ≤ Rrup ≤ 200 km
Z_TOR: Depth to the top of the coseismic rupture plane(used in “style-of-foulting” and “hanging wall”contributions, 0<Z_TOR<15 km.In our work hanging wall contribution is not considered.If VS30 ≥ 1100 m/s the soil response is assumed linearfor all the periods.
PEER strong motiondatabase, referred to simplyas the NGA database.
Chiou & Youngs (2008)
PGV, PGA,PSA for 0.01 to 10 s.Orientation-independent
average horizontal
component
Mw ≥ 4Mw ≤ 8.5 for strike-slip eventsMw ≤ 8 for reverse and normal faulting events
Closest distance to the rupture plane0 ≤ Rrup ≤ 200 km
Z_TOR: Depth to the top of rupture (used in “sourceeffects and hanging wall” contributions )Z_1.0: Depth to the 1 km/s shear wave velocity horizon(used in “sediments” contribution), which is minimumfor Z_1.0=0. Z_1.0= 40 m is suggested.In our work hanging wall contribution is not considered.Site effects are null for VS30≥1130 m/s (linearresponse).150≤VS30≤1500 m/s
PEER-NGA database (3551recordings from 173earthquakes).This GMPE was used also forthe volcanic zone.
Boore & Atkinson (2008)
PGV, PGA, PSA for 0.01
to 10 s.Average
horizontal component
5.0 ≤ Mw ≤ 8.0
Closest horizontal distance to the surface projection of the fault planeRJB ≤ 200 km
It does not account for basin response and depth-to topof rupture model as Abrahamson & Silva (2008) andCampbell & Bozorgnia (2008).If VS30(Rock)>760 m/s site response is linear and siteamplification is null.
Developed from NGA database, calibrated for Western US and other similar tectonically active region of shallow crustal faults. Representative of the NGA models and confidently applicable within Europe (Stafford et al., 2008)
Attenuation Equation
ApplicationMagnitude definition
and limitationsDistance definition and
limitationsFault depth definition and contributions to
seismic responceDatabase
Equation and limitations limitations seismic responce
Sadigh et al. (1997)
PGA and PSA for 0.07 to 4 s.
Horizontal component
45.0 ≤ Mw ≤ 8.0+
Shorter distance to the rupture surface for
earthquakes with available fault models, otherwise hypocentral distance
Rrup ≤ 100 km
Strike-slip and normal events are distinguished from reverse/thrust faulting events (amplification
coefficient of 1.2).VS30 (Rock) > 750 m/s
California earthquake (<1994) plus Gazli (USSR, 1976) and Tabas (Iran, 1978) earthquakes
Comparison of GMPEs with available data
10-2
10-1
100
Mw =6.1 T =0 sec
Acc
ele
ratio
n (
g)
10-2
10-1
100
Mw =6.1 T =0.2 sec
Acc
ele
ratio
n (
g)
5252
102
10-3
10-2
10-1
100
Mw =6.1 T =1 sec
Acc
ele
ratio
n (
g)
Hypocentral distance (km)
102
10-3
Hypocentral distance (km)10
210
-3
Hypocentral distance (km)
Youngs et al. 97 - average " - average +σ " - average - σKanno et al., 06 - average " - average +σ " - average - σLin & Lee 08 - average " - average +σ " - average - σZhao et al. 06 - average " - average +σ " - average - σAtkinson & Boore 08 - average " - average +σ " - average - σ2000-10-4 component=1 station=TPTC2000-10-4 component=2 station=TPTC2000-10-4 component=1 station=TBH2000-10-4 component=2 station=TBH
INTRAPLATE EVENT
October 4, 2000
Comparison of GMPEs with available data
-4
10-3
10-2
10-1
100
Mw =5.8 T =0 sec
Acc
ele
ratio
n (
g)
-4
10-3
10-2
10-1
100
Mw =5.8 T =0.2 sec
Acc
ele
ratio
n (
g)
5353
INTERFACE EVENT
June 8, 1999
102
10-4
10-3
10-2
10-1
100
Mw =5.8 T =1 sec
Acc
ele
ratio
n (
g)
Hypocentral distance (km)
102
10-4
Hypocentral distance (km)10
210
-4
Hypocentral distance (km)Youngs et al. 97 - average " - average +σ " - average - σKanno et al., 06 - average " - average +σ " - average - σLin & Lee 08 - average " - average +σ " - average - σZhao et al. 06 - average " - average +σ " - average - σAtkinson & Boore 08 - average " - average +σ " - average - σ1999-6-8 component=1 station=mbra1999-6-8 component=2 station=mbra1999-6-8 component=1 station=gbra1999-6-8 component=2 station=gbra1999-6-8 component=1 station=GPAA1999-6-8 component=2 station=GPAA
Comparison of GMPEs with available data
10-3
10-2
10-1
100
Mw
=5.4 T =0 sec
Acc
ele
ratio
n (g
)
10-3
10-2
10-1
100
Mw
=5.4 T =0.2 sec
Acc
ele
ratio
n (g
)
5454
CRUSTAL EVENT
December 3, 2004
102
10-4
Hypocentral distance(km)10
210
-4
Hypocentral distance(km)
102
10-4
10-3
10-2
10-1
Mw
=5.4 T =1 sec
Acc
ele
ratio
n (g
)
Hypocentral distance(km)
Zhao et al. 08 - average " - average +σ " - average - σKanno et al. 06 - average " - average +σ " - average - σAbrahamson & Silva 08 - average " - average +σ " - average - σCampbell & Bozorgnia 08 - average " - average +σ " - average - σBoore & Atkinson 08 - average " - average +σ " - average - σ2004-12-3 component=1 station=ALNG2004-12-3 component=2 station=ALNG2004-12-3 component=1 station=TCHG2004-12-3 component=2 station=TCHG2004-12-3 component=1 station=TBH2004-12-3 component=2 station=TBH
10-2
10-1
100
Mw
=6.3 T =0 sec
Acc
ele
ratio
n (g
)
Sadigh et al., 97 - average " - average +σ " - average - σZhao et al. 08 - average " - average +σ " - average - σKanno et al., 06 - average " - average +σ " - average - σAbrahamson & Silva 08 - average " - average +σ " - average - σ
Comparison of GMPEs with available data
5555
101
102
10-4
10-3
Acc
ele
ratio
n (g
)
Hypocentral distance (km)
" - average - σChiou & Youngs 08 - average " - average +σ " - average - σSalazar, 04 - average " - average +σ " - average - σMcVerry et al., 06 - average " - average +σ " - average - σ2004-11-21 - PGA from Bengoubou-Valerius et al. 08
VOLCANIC ARC EVENT
November 21, 2004
Adopted GMPEs
SUBDUCTION ZONES:
� Youngs et al. (1997)� Atkinson and Boore (2003-2008)� Zhao et al. (2006)� Kanno et al. (2006)
Cornell-Mc-Guire method:
5656
CRUSTAL ZONES:
� Kanno et al. (2006)� Zhao et al. (2006)� Abrahamson and Silva (2008)� Boore and Atkinson (2008)� Campbel and Bozogornia (2008)
VOLCANIC ZONE:
� Sadigh et al. (1997)� Zhao et al. (2006)� Kanno et al. (2006)� Abrahamson and Silva (2008)� Chiou and Youngs (2008)
� Kanno et al. (2006)� Lin and Lee (2008)
Zone-free approach: Zhao et al. (2006), Kanno et al. (2006)
PSHA analysis and resultsPSHA analysis and results
5757
PSHA analysis and resultsPSHA analysis and results
RESULTSRESULTS
5858
Influence of Influence of seismogenicseismogenic zones zones
-92,16
-85.5,13
-92,10
-89.21,13.71
LOG N = 4.84 – 0.84 M
LOG Y = 1.8479+0.298M-LOGR-0.0013R
SIGMA = 0.2408
M MIN = 4.0 AND M MAX = 8.2
Comparison of hazard programs
-85.5,10FZ RISK OUR PROGRAM - SRC
Peak Ground Acceleration
(cm/s/s)
Number of earthquakes / year Number of earthquakes / year
50.00 0.133 0.134
100.00 0.0169 0.0170
150.00 0.0466 0.00468
200.00 0.00169 0.00173
250.00 0.000738 0.00075
300.00 0.000357 0.000361
350.00 0.000180 0.000180
400.00 0.0000998 0.000102
Island of TrinidadCornell-McGuire approach
Hazard dominated by Zone 11 –
Port of Spain (Trinidad)T=0s
1.00E+00
1.00E+01
1.00E+02
Ann
ual F
requ
ency
of E
xcee
danc
e
SZ01
SZ02
SZ03
SZ04
SZ05
SZ06
SZ07
1/475 = 2.1E-031/2475 = 4.0E-04
6060
Zone 11 –North of Paria Peninsula
Zone 12 (Trinidad Faults) and Zone 10 (transitions) also contribute
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.1 1 10
Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
SZ07
SZ08
SZ09
SZ10
SZ11
SZ12
SZ13
SZ14
SZ15
ALL
RP=2475 y
RP=475 y
Island of Trinidad Cornell-McGuire approachHazard dominated by Zone 11
Port of Spain (Trinidad)RP=2475 years
1.20
1.40
1.60
SZ01
SZ02
SZ03
SZ04
SZ05
SZ06
SZ07
6161
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0.00 0.50 1.00 1.50 2.00 2.50 3.00
T(s)
SA
(g)
SZ07
SZ08
SZ09
SZ10
SZ11
SZ12
SZ13
SZ14
SZ15
ALL
Zone-free approach - GMPE Zhao etal. (2006)Hazard dominated by deep seismicity; depth > 50 km
Port of Spain (Trinidad)T=0s
1.00E-01
1.00E+00
1.00E+01
Ann
ual F
requ
ency
of E
xcee
danc
e
Deep
Shallow
Total
RP=2475 y
1/475 = 2.1E-031/2475 = 4.0E-04
Island of Trinidad
6262
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.10 1.00 10.00Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
RP=2475 y
RP=475 y
Zone-free approach - GMPE Kanno etal. (2006)Hazard dominated by deep seismicity seismicity depth > 30 km
Port of Spain (Trinidad)T=0s
1.00E-01
1.00E+00
1.00E+01
Ann
ual F
requ
ency
of E
xcee
danc
e
Deep
Shallow
Total
RP=2475 y
1/475 = 2.1E-031/2475 = 4.0E-04
Island of Trinidad
6363
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.10 1.00 10.00Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
RP=2475 y
RP=475 y
Island of Barbados
Cornell-McGuire approach
Hazard
BarbadosT=0s
1.00E-01
1.00E+00
1.00E+01
1.00E+02
Ann
ual F
requ
ency
of E
xcee
danc
e
SZ01
SZ02
SZ03
SZ04
SZ05
SZ06
SZ07
SZ08
1/475 = 2.1E-031/2475 = 4.0E-04
6464
Hazard dominated by Zones 3 –Interface subduction and Zone 5 – Intra plate subduction
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.1 1 10
Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
SZ08
SZ09
SZ10
SZ11
SZ12
SZ13
SZ14
SZ15
ALL
RP=2475 y
RP=475 y
Cornell-McGuire approachHazard dominated by Zones 3 and 5
BarbadosRP=2475 years
1.00
1.20
SZ01
SZ02
SZ03
SZ04
SZ05
SZ06
SZ07
Island of Barbados
6565
0.00
0.20
0.40
0.60
0.80
0.00 0.50 1.00 1.50 2.00 2.50 3.00
T(s)
SA
(g)
SZ07
SZ08
SZ09
SZ10
SZ11
SZ12
SZ13
SZ14
SZ15
ALL
Zone-free approach - GMPE Zhao etal. (2006)Hazard dominated by deep seismicity; depth > 50 km
BarbadosT=0s
1.00E-01
1.00E+00
1.00E+01
Ann
ual F
requ
ency
of E
xcee
danc
e
Deep
Shallow
Total
1/475 = 2.1E-031/2475 = 4.0E-04
Island of Barbados
6666
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.10 1.00 10.00Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
RP=2475 y
RP=475 y
Zone-free approach - GMPE Kanno etal. (2006)Hazard dominated by deep seismicity depth > 30 km
BarbadosT=0s
1.00E-01
1.00E+00
1.00E+01
Ann
ual F
requ
ency
of E
xcee
danc
e
Deep
Shallow
Total
1/475 = 2.1E-031/2475 = 4.0E-04
Island of Barbados
6767
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.10 1.00 10.00Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
RP=2475 y
RP=475 y
Island of Dominica
Cornell-McGuire approachHazard dominated by Zone 4 – Intra plate and Zone 1 –
DominicaT=0s
1.00E-01
1.00E+00
1.00E+01
1.00E+02
Ann
ual F
requ
ency
of E
xcee
danc
e
SZ01
SZ02
SZ03
SZ04
SZ05
SZ06
SZ07
1/475 = 2.1E-031/2475 = 4.0E-04
6868
plate and Zone 1 –Volcanic island-arc
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.1 1 10
Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
SZ08
SZ09
SZ10
SZ11
SZ12
SZ13
SZ14
SZ15
ALL
RP=2475 y
RP=475 y
Cornell-McGuire approachHazard dominated by Zone 4 and Zone 1
DominicaRP=2475 years
1.40
1.60
1.80
SZ01
SZ02
SZ03
SZ04
SZ05
SZ06
SZ07
Island of Dominica
6969
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
0.00 0.50 1.00 1.50 2.00 2.50 3.00
T(s)
SA
(g)
SZ07
SZ08
SZ09
SZ10
SZ11
SZ12
SZ13
SZ14
SZ15
ALL
Zone-free approach - GMPE Zhao etal. (2006)Hazard dominated by deep and shallow seismicity
DominicaT=0s
1.00E-01
1.00E+00
1.00E+01
Ann
ual F
requ
ency
of E
xcee
danc
e
Deep
Shallow
Total
RP=2475 y
1/475 = 2.1E-031/2475 = 4.0E-04
Island of Dominica
7070
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.10 1.00 10.00Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
RP=2475 y
RP=475 y
Zone-free approach - GMPE Kanno etal. (2006)Hazard dominated by deep and shallow seismicity
DominicaT=0s
1.00E+00
1.00E+01
Ann
ual F
requ
ency
of E
xcee
danc
e
Deep
Shallow
Total
1/475 = 2.1E-031/2475 = 4.0E-04
Island of Dominica
7171
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
0.01 0.10 1.00 10.00Acceleration (g)
Ann
ual F
requ
ency
of E
xcee
danc
e
Total
RP=2475 y
RP=475 y
• Conclusion- The complex tectonics of the Eastern
Caribbean suggests a detail seismogenicsources delimitation to be incorporated in thehazard assessment, which is dominated byintra-plate seismicity in most of the islandsintra-plate seismicity in most of the islandswith an important contribution of the upper-crustal earthquakes located in the volcanicarc as well.
- The installation of a new strong motionnetwork is a must to develop GMPEs for theEastern Caribbean.
7272
HAZARD MAPS 2475 YEARS RETURN PERIODAPPLICATION
7373
Design spectral acceleration parameters IBC – ASCE 7_05
• SDS = 2/3*Fa * Ss
• SD1 = 2/3*Fv * S1 Spectral acceleration for 1.0 s
Seismic Hazard maps
Spectral acceleration for 0.2 s
7474
Fa and Fv: depends on soil conditionsFor rock site conditions – CLASS B It Corresponds to a shear wave velocity Vs = 760 m/s:
Fa = 1.0 and Fv = 1.0
SDS
1Da
SS
T=
ELASTIC DESIGN RESPONSE SPECTRUM
7575
To
Ts
SD1
T
Practical Examples
• Get the design response spectra and the seismic coefficients Cs for the following sites:
7676
a) Scarborough -Tobago (Hotel – 20 stories)
b) Indian River – Dominica (Bridge – 30 m multi-span intermediate columns with height H = 15 m)
7777
Tobago Hotel
7878
1.85 g
7979
0.375 g
• Reading from the maps
1 0.250.2 0.2* 0.04D
o
ST s= = =
1
1.85
0.375SS g
S g
== 1
(2 / 3)*1.85 1.23
(2 / 3)*0.375 0.25DS
D
S g g
S g g
= == =
8080
0.4 0.6 1.23* 0.4 0.6 0.492 18.450.04a DS
o
T TS S T
T
= + = + = +
0.2 0.2* 0.041.23o
DS
T sS
= = =
T : the fundamental period of the structure in “s”
1 0.250.20
1.23D
SDS
ST s
S= = =
1.23a DSS S g= = Flat spectral response
Period to which begin the exponential decay
8181
1 0.25Da
S gS
T T= =
Spectral exponential decay
The Seismic Coefficient Cs
Fundamental Period:
T = 0.1 n = 0.1 (20 ) = 2.0 s
n: number of stories
1 0.25Da
S gS = =
1.23a DSS S g= =
0.492 18.45aS T= +
8282
T = 2.0 s
Cs = 0.13g
Reduction factor R= 8.0
Cs = 0.13g/8=0.016g
aST T
= =
0.20s
0.04s
0.13 g
8383
ETABS MODEL
MULTI SPAN BRIDGEINDIAN RIVER - DOMINICA
8484
Indian River Indian River1.55g 0.47g
8585
• Reading from the maps
1 0.310.2 0.2* 0.06D
o
ST s= = =
1
1.55
0.47SS g
S g
== 1
(2 / 3)*1.55 1.03
(2 / 3)*0.47 0.31DS
D
S g g
S g g
= == =
8686
0.4 0.6 1.03* 0.4 0.6 0.41 10.30.06a DS
o
T TS S T
T
= + = + = +
0.2 0.2* 0.061.03o
DS
T sS
= = =
T : the fundamental period of the structure in “s”
1 0.310.30
1.03D
SDS
ST s
S= = =
1.03a DSS S g= = Flat spectral response
Period to which begin the exponential decay
8787
DS
1 0.31Da
S gS
T T= = Spectral exponential
decay
The Seismic Coefficient Cs
Design of a column:
Fundamental Period:
T = 0.75 s (H=15 m and 30 m span)
1 0.31Da
S gS
T T= =
1.03a DSS S g= =
0.41 10.3aS T= +
8888
Cs = 0.42g/8=0.053g
Reduction factor R= 8.0
Cs = 0.42g
aST T
= =
0.30s
0.06s
0.42 g
Thank you
8989
Questions ?