1. Kerry Sieh TO Annual Meeting 13 November 2007 Kerry Sieh TO Annual Meeting 13 November 2007 Soft corals lifted about 10 cm during the September 2007 earthquakes Behavior of the Sunda Megathrust in Sumatra

2. Caltech John Galetzka Mohamed Chlieh Don Helmberger JP Avouac Aron Meltzner Ozgun Konca Yaru Hsu Mark Simons Andrew Kositsky Indonesian Institute of Sciences Danny Natawidjaja Bambang Suwargadi Dudi Prayudi Imam Suprihanto Scripps Yehuda Bock Paul Jameson Peng Fang Linette Prawirodirjo Kyoto University Shigehiro Fujino USC Jose Borrero Soft corals lifted about 10 cm during the September 2007 earthquakes Collabora tors SponsorsSponsors

3. To understand the behavior of a great active fault at time scales important to understanding the earthquake cycle. Through the millennia Through the centuries During large earthquakes

4. base modified from NASA World Wind/Blue Marble from Rich Briggs, after Briggs et al 2006 Deformation over millennia

6. by Rich Briggs The earthquake cycle Nias-Simeulue section Mentawai section southern Aceh-Andaman section Deformation over centuries

7. Nias-Simeulue and southern Aceh- Andaman sections Fossil Microatoll deaths in 1861 Fossil Microatoll deaths in 1861 Fossil Microatoll deaths in 1843 Fossil Microatoll deaths in 1843 Fossil Microatoll deaths in ~1799 Fossil Microatoll deaths in ~1799 (tentative) Fossil Microatoll deaths in ~1440 Fossil Microatoll deaths in ~1440 Fossil Microatoll deaths in ~1390 Fossil Microatoll deaths in ~1390 Fossil Microatoll deaths in ~1327 Fossil Microatoll deaths in ~1327 from Aron Meltzner

8. The Mentawais

9. Bulasat Years (AD) Elevation relative to modern sea level AD 1357±14 1797 & 1833 2007 Sawtooth curve of paleoseismic events Not yet published

10. Simangan ya Years (AD) Elevation relative to modern sea level 2007 1.8±0.1 m 1.5±0.3 m 1.4±0.2 m 0.15 m ~0.2 m? Sawtooth curve of paleoseismic events Not yet published

12. Narrow trench-parallel graben on an islet west of South Pagai island

14. Victims of uplift -- dead Portuguese Men-o-War Southern tip of South Pagai island

15. from Briggs et al (2006) Vertical deformation in the field Mega island, 4˚S Measurements

16. Minor emergence near northern end of uplift Island at the western entrance to Sikakap strait

17. Field measurements

19. Map of field measurements Not yet published

20. Map of contoured field measurements Not yet published

21. Map of contoured field measurements Not yet published

22. Map of contoured field measurements Not yet published

23. L-band InSAR from the Japanese ALOR satellite

24. cGPS measurements Sumatran GPS Array (SuGAr) as of Sept 13, 2007 proposed early 2008

25. from Ozgun Konca

26. Horizontal (black) and vertical (red) Displacements during the M w 8.4 mainshock from Peng Fang via Ozgun Konca Map of cGPS displacements Not yet published

27. Silab u (SLB U) 15-sec cGPS from Jeff Genrich Strong-ground-motion from Chris Stephens via Ken Hudnut M w 8.4 K2 data Not yet publish ed 15-sec data Not yet published 1-sec data Not yet published

28. Comparison of K2 and cGPS velocity records at Silabu

29. Horizontal (black) and vertical (red) Displacements during the M w 7.9 aftershock from Peng Fang via Anthony Sladen Map of SuGAR vectors Not yet published

30. Silab u (SLB U) 15-sec 1-sec cGPS from Jeff Genrich Strong-ground-motion from Chris Stephens via Ken Hudnut M w 7.9 and 7.0 aftershocks 7.9 7.0 7.9 10 cm 10 min 10 cm K2 data Not yet publish ed 15-sec data Not yet published 1-sec data Not yet published

31. Pukarayat (PKRT) cGPS from Jeff Genrich M w 7.9 and 7.0 aftershocks 15-sec 7.9 7.0 7.9 15-sec data Not yet published 1-sec data Not yet published

32. Horizontal (black) and vertical (red) Displacements during the M w 7.0 aftershock from Peng Fang via Anthony Sladen Map of SuGAR vectors Not yet published

33. M w 8.4 inversions cGPS and teleseismic data by Ozgun Konca Teleseismic data only Data = black Model horizontal (red) and vertical (gray) Analyses Maps of inversions Not yet published

34. M w 8.4 inversions by Ozgun Konca Data = black Model horizontal (red) and vertical (gray) cGPS with coral at Mega Detail Map of inversions Not yet published

35. by Ozgun Konca M w 8.4 inversions Model displacements Horizon tal Vertical (m) from cGPS data only Maps of vertical deformation estimated from inversion of SuGAR data Not yet published

36. Joint seismic/cGPS inversion of the 7.9 aftershock by Anthony Sladen Data = black Model horizontal = red and vertical = gray Maps of inversion Not yet published

37. Joint seismic/cGPS inversion of the 7.9 aftershock by Anthony Sladen Maps of inversion Not yet published

38. Tsunami field data by Jose Borrero Measurements of runup along mainland coast Not yet published

39. Combined source of mainshock and two aftershocks -- M w 8.45 Data = black Model horizontal = red Model vertical = gray by Anthony Sladen Maps of slip from inversion Not yet published

40. from Jean-Philippe and Anthony Calculated interferogram from combined model

41. Base map from Mohamed Chlieh Comparison of 50-year coupling and September events How do the Sept 2007 events fit in to the long-term picture? Map Not yet published

42. from Mohamed, Anthony and Jean- Philippe

43. Accumulated potential slip versus slip during 8.4 in September Map comparing slip in 2007 with slip deficit since 1833 and 1797 Not yet published

44. 17971833 Natawidjaja et al, JGR, 2006

45. 1833 2007 Maps of 2007 uplift Not yet published

46. Bulasat Years (AD) Elevation relative to modern sea level 1797 & 1833 2007 Sawtooth curve of paleoseismic events Not yet published

47. by Rich Briggs