Pelatihan : Techniques in Active Tectonic Study Juni 20-Juli 2, 2013

1. Pelatihan : Techniques in Active Tectonic Study Juni 20-Juli 2, 2013 Instruktur: Prof. J Ramon Arrowsmith (JRA) Dari Arizona State University (ASU) - US Tempat Pelaksanaan: Ruang Pangea, Laboratorium Gempabumi (LabEarth) – Puslit Geoteknologi LIPI dan Kuliah lapangan akan dilakukan disekitar Sesar Lembang, Jawa Barat. * Lebih jelas baca TOR/KAK dan daftar acara

2. Shallow geophysics and cone penetrometer testingOutline of this lecture • “remote sensing” of the subsurface (geophysics and drilling) • Seismic methods • CHiRP applied to subaqueous • GeoRadar • Electrical resistivity • Cone Penetrometer Testing (CPT) Much of this lecture comes from this excellent book

3. “remote sensing” of the subsurface (geophysics and drilling) • Define shallow stratigraphy and structure • Trace faults to greater depth than can be reached with trenching • Detect buried faults Depth scales can be a few meters to a few km

4. Seismic reflection geometry Multilayer Simple zero offset http://principles.ou.edu/seismic_explo/reflect/reflect.html http://principles.ou.edu/seismic_explo/reflect/reflect.html Increase signal strength with folding and stacking http://principles.ou.edu/seismic_explo/reflect/reflect.html http://www.geologicresources.com/seismic_reflection_method.html

5. Seismic reflection and refraction

9. CHIRP profiling, coring, bathymetry

10. Flying ITB to Lake Tahoe, California

11. Exploring Lake Tahoe, California (USGS)

12. CHIRP: A type of sonar technology utilizing separate projector and hydrophone where the projector transmits digitally produced, linear, swept FM pulses resulting in an increased system bandwidth. As these systems are multifrequency, greater bandwidth rather than the pulse length results in higher theoretical range resolution. Chirp technology has been successfully used in sub-bottom profilers and is being developed for long-range side-scan applications. http://www.seaconnectwiki.org/doku.php/sonar_glossary:chirp Profiles were collected with the Edgetech SubScan Chirp system. Chirp profiles presented here use a 1–5.5 kHz pulse with a 10 ms duration, a 1–5.5 kHz pulse with 30 ms duration, or a 1–6 kHz pulse witha 50 ms duration (Smith, et al., 2013)

15. GeoRadar or Ground Penetrating Radar • Similar principles as seismic reflection except that a microwave signal is used and return signals are reflected from materials with different dielectric constants. http://upload.wikimedia.org/wikipedia/commons/2/29/Ground_Penetrating_Radar_in_use.jpg

16. GeoRadar

18. Electrical Resistivity Tomography--a geophysical technique for imaging sub-surface structures from electrical resistivity measurements made at the surface, or by electrodes in one or more boreholes (http://en.wikipedia.org/wiki/Electrical_resistivity_tomography)

19. G. Marliyani Cone penetrometer test (CPT) CPT Rig Grant et al, 1997 Tip cone

20. Paul W. Mayne Standard Penetration Test Rotary-drilled Borehole Standard Penetration Test (SPT) Procedures: ASTM D 1586 N = measured Number of Blows to drive sampler 300 mm into soil.

21. Paul W. Mayne Cone Penetration Tests (CPT) Cone Trucks Mobile 25-tonne rigs with enclosed cabins to allow testing under all weather conditions

23. G. Marliyani • Total 38 CPT soundings • Seven shallow trenches (2009-2010) CPT and Trenches transect

24. 2009 Trench G. Marliyani 400m long trench Trench 1, Summer 2009

25. G. Marliyani

26. G. Marliyani CPT Profile 1

27. G. Marliyani CPT Profile 2

28. Shallow geophysics and cone penetrometer testingOutline of this lecture • “remote sensing” of the subsurface (geophysics and drilling) • Seismic methods • CHiRP applied to subaqueous • GeoRadar • Electrical resistivity • Cone Penetrometer Testing (CPT) Much of this lecture comes from this excellent book