PEMBUATAN PETA HAZARD GEMPA DENGAN SOFTWARE USGS DAN PEMODELAN SUMBER BACKGROUND M. ASRURIFAK

Transkripsi

1 PEMBUATAN PETA HAZARD GEMPA DENGAN SOFTWARE USGS DAN PEMODELAN SUMBER BACKGROUND MASYHUR IRSYAM BAMBANG BUDIONO WAHYU TRIYOSO M. ASRURIFAK SRI WIDIYANTORO ENGKON KERTAPATI WORKSHOP Peta Zonasi Gempa Indonesia Terpadu Untuk Membangun Kesiapan Masyarakat Jakarta, 21 Juli 2009 Software: EZFRISK Risk Engineering, Cal. USA USGS Software for Probabilistic Seismic Hazard Analysis

2 LOGIC TREE KARAKTERISASI SUMBER GEMPA Ketidakpastian dalam PSHA : Aleatory uncertainty (randomness) Epistemic uncertainty (uncertainty) Aleatory diperhitungkan secara langsung dalam perhitungan matematik (standar deviasi) Epistemic diperhitungkan menggunakan logic tree 4

3 MAJOR TECTONIC INDONESIA REGION N. Sumatra Subductio n 2. Aceh 3. Tripa 4. Renun 8. Sumpur Jawa- Sumba Subduction N. Sulawesi Subductio n 56. Sulu thrust W. Molucca Subductio n Timor Subduction Philippine Subduction E. Molucca Subduction 77. Manokwari trench Irian Subductio n 75. Ransiki 70. Yapen 1.Seulimeum 5. Toru 9. Sianok 12. Siulak 57. Gorontalo 54. Batui thrust 74. Sorong 6. Angkola 13. Dikit 50. Palu-Koro 72. Sula-Sorong 7. Barumun 14. Ketaun 53. Poso 10. Sumani 18.Semangko 11. Suliti 51. Matano 15. Musi 31. Baribis 73. Sorong-Maluku 58. Lawanopo 33. Semarang 34. Wetar back arc 78. Lowland S. Sumatra 16. Manna 52. Walanae 55. Tolo thrust 71. Tarera-Aidun Subductio 17. Kumering n 30. Bumiayu 19.Sunda 34. Jogja 76. Membrano 36. Flores back arc Banda Sea thrust tbelt 32. Cimandiri Collision 79 Highland thrust belt

4 References to describe faults N. Sumater Subduction 2. Aceh 3. Tripa 4. Renun 5. Toru 1. Seulimeum 6. Angkola 7. Barumun 10. Sumani 11. Suliti 15. Musi S. Sumater Subduction 16. Manna 17. Kumering 32. Cimandiri 30. Bumiayu 8. Sumpur 9. Sianok 12. Siulak 13. Dikit 14. Ketaun 18. Semangko 19. Sunda 31. Baribis 33. Semarang 34. Jogja Jawa-Sumba Subduction REFERENCE

5 Removal of Dependent events Removal of aftershock events follows Gardner and Knopoff (1974) conducted using software ZMAP by Wiemer (2001) Main shocks

6 Interface Subduction (Megathrust) EPICENTRE MAIN SHOCK (DEPTH: 0 50 KM) TANPA MEGATHRUST (INTERFACE ZONE)

7 EPICENTRE MAIN SHOCK (DEPTH: 0 50 KM) TANPA MEGATHRUST DAN FAULT AREA Spatially smoothed-gridded seismicity SHALLOW BACKGROUND (0-50 KM)

8 Spatially smoothed-gridded seismicity Shocks km (Intraslab)

9 Shocks km (Intraslab) Shocks km (Intraslab)

10 Shocks km (Intraslab) ATTENUATION

11 Institution ITB (Jodi Firmansyah dan Masyhur Irsyam) Public Work (Theo F. Najoan) Attenuation Function Youngs, 1997 Boore et al., 1997 Sadigh, 1997 Fukushima Software EQRISK (USGS) SEISRISK III Geological Research and Development (Engkon Kertapati) Private Consultant (Teddy Boen dan Harris Shah) Fukushima Crouse Fukushima SEISRISK (USGS) IRAS (RMS + Univ. of Stanford) ATTENUATION: Shallow Background & Fault Sources 1. Boore-Atkinson NGA. (Boor and Atkinson, 2008) 2. Campbell-Bozorgnia NGA. (Campbell and Bozorgnia, 2008) 3. Chiou-Youngs NGA. (Chiou and Youngs, 2008)

12 ATTENUATION: Interface Source Zones (Megathrust) 1. Geomatrix subduction (Youngs et al, SRL, 1997) 2. Atkinson-Boore BC rock & global source. (Atkinson & Boore, 2003) 3. Zhao et al., with variable V s-30. See BSSA, June, 2006 (Zhao et al, 2006) ATTENUATION: Benioff Source Zones (Intraslab) 1. AB intraslab seismicity Puget Sound reg. BC-rock cond. (Atkinson -Boore, 1995) 2. Geomatrix slab seismicity rock, 1997 srl. july (Youngs et al, 1997) 3. AB 2003 intraslab seismicity world data, BC-rock cond. (Atkinson -Boore, 2003)

13 MAGNITUDE DISTRIBUTION Log Frequency of earthquake Shallow Background GR Deep Background GR Fault Char GR Subduction Interface GR Subduction Interface Pure Char (Sumatera only) M5 M6.5 M7.8 Mmax fault Mmax Interface M SUMATRA

14 HAZARD 5 Hz (0.2 sec) for 10% p.o.a. in 50 years HAZARD 1 Hz (1.0 sec) for 10% p.o.a. in 50 years

15 HAZARD PGA for 10% p.o.a. in 50 years

16 ATC-40 Performance Based Design 31 V b 500 tahun 2500 tahun Structural Stability Level, Collapse Prevention (CP-MCE-2%-50 Yr) Immediate Occupancy Level (IO) Life Safety Level (LS- Rare-10%,50Yr) Collapse Linear Elastic Range Damage Control Increasing Earthquake Demand Limited Safety Lateral Roof Displacement, D Peta yg disajikan masih dlm proses iterasi penyempurnaan, validasi dan verifikasi Mengajak keterlibatan semua fihak Peta Hazard Spektra yg maksimum, memenuhi prosedur berdasarkan standar internasional, dan diterima semua fihak

17