The Establishment of a Geophysics Fi Eld Camp in Northern Thailand

SPECIALGeoscientists SECTION: Without G eoscientists borders Without borders

The establishment of a geophysics ﬁ eld camp in northern Thailand

LEE LIBERTY, SPENCER WOOD, KASPER VANWIJK, EMILY HINZ, and DYLAN MIKESELL, Boise State University FONGSAWARD SINGHARAJAWARAPAN, Chiang Mai University JEFFREY SHRAGGE, University of Western Australia

s a participant in SEG’s Geoscientists Without Borders Overview Aprogram, we have developed a geophysics fi eld camp in Th e Geoscientists Without Borders (GWB) program was cre- northern Th ailand to train students and professionals from ated to help connect universities and industries with com- throughout Southeast Asia in fi eld-based geophysical methods. munities in need through projects using applied geophysics Over the past two years, faculty, technicians, professionals, as a means to benefi t people and the environment around the and students from 18 institutions and 11 countries have world. With GWB funding, our goal is to educate and con- acquired, processed, and interpreted geophysical data at fi eld nect local geoscientists with students throughout Southeast sites in and around Chiang Mai, Th ailand. Participation Asia (Figure 1). Our objective with fi eld-based training is to from undergraduate students, graduate students, and private instruct participants using modern geophysical instrumenta- and public sector geoscience professionals provides a broad tion and software to address environmental and engineering base of experience, background, and insight. Our training problems by utilizing a range of geophysical tools. During has provided opportunities for cross-cultural collaboration 2010 and 2011, approximately 100 professionals and students and education, and a greater use of fi eld-based geophysical participated in the Chiang Mai, Th ailand trainings (Table methods for academic, private sector, and government 1). Our goal is to not only directly tackle specifi c near-surface agencies throughout Southeast Asia. geophysical projects, but to provide scenarios to train local professionals and students to address hazards or geosciences problems found within their own country’s borders. By providing the tools and skills necessary to address groundwater, geotechnical, and archaeology problems, we hope to leave a lasting impact on geoscientists and geotechnical projects throughout Southeast Asia. Field sites were selected to train participants in the use of geophysical methods to address groundwater, archaeology, and Figure 1. (a) Map of Th ailand and geohazard concerns throughout the Chi- neighboring countries. Students and ang Mai Basin, Th ailand (Figure 1). Th e professionals from Th ailand, Burma, Laos, fi eld camp consists of one week of geo- Malaysia, Indonesia, and Vietnam participate physical data acquisition using seismic, in our training. (b) Northern Th ailand terrain ground-penetrating radar, electromagnet- map. Th e Chiang Mai-Lamphun Basin, is one of many intermountain fault-bounded ic, resistivity, gravity, and magnetic meth- extensional basins of the region. All geophysical ods (Figure 2). A second week includes fi eld sites are within 20 km of Chiang Mai. data analysis, interpretation, presenta- tion and a student-authored report. Data Institute Institute sets, reports, and presentations generated Boise State University (USA) Kasetsart University (Th ailand) during our training are freely available Chiang Mai University (Th ailand) Mahidol University (Th ailand) (http://cgiss.boisestate.edu/gwb) and are being used for further instruction (e.g., Chulalongkorn University (Th ailand) Phu Bia Mining Limited (Laos) data reprocessing, improved interpreta- Colorado School of Mines (USA) Prince of Songkla University (Th ailand) tions). Th is model was revised from other Department of Mineral Resources Royal Irrigation Department (Th ailand) geophysical fi eld schools (e.g., Colorado (Th ailand) School of Mines, Boise State University Department of Groundwater Resources Siam Tone Co., Ltd. (Th ailand) and Imperial College, 2010) and existing (Th ailand) collaborations between institutions. Electricity Generating Authority Universiti Teknologi Petronas (Malaysia) Faculty, graduate students, and tech- (Th ailand) nicians from the United States, Canada, Gadjah Mada University (Indonesia) Vietnam National University (Vietnam) Australia, and Th ailand provide instruc- Table 1. Participant institutions from 2010 and 2011.

414 The Leading Edge April 2011 Geoscientists Without borders

tion both in the classroom and fi eld settings (Table 2). Intro- ductory lectures by local experts and visiting faculty discuss fi eld sites and overview geophysical methods applicable at each site. An instructor for each geophysical tool and fi eld site guides the participants through training in acquisition, processing, and interpretation. All instruction is in English with at least one bilingual (Th ai) participant in each group and a 3:1 student/instructor ratio. Participants from government and private agencies looking to broaden their geophysical base provide additional benefi t of experience and lead- ership to student participants. Many institutions provide geophysical instrumentation and technicians to benefi t the fi eld camp and minimize the number of geophysical instru- ments brought from western countries.

Field sites Th e area surrounding Chiang Mai, Th ailand (Figure 1) is ideal for geophysical training due to pleasant seasonal weath- er, rich culture, the large physical property contrast within a sedimentary basin, and a wide range of geological-, hydro- geological-, archaeological-, and hazard-related problems. Selection of fi eld sites is based on proximity to Chiang Mai to address a broad assortment of science objectives that are identifi ed by geoscience faculty at Chiang Mai University. To provide experience with a range of geophysical tools and objectives, we image a shallow aquifer to characterize geol- Figure 2. (clockwise from top left): Geonics ProTEM 57 time- ogy and hydrogeology at both water table and basin-scale domain electromagnetic acquisition system with instructor Rob Harris depths. Additionally, we assess earthquake hazards for the at Mae Hia; high-resolution seismic survey to map a buried wall at Wat Pan Sao; Th ai and Indonesian students acquire seismic data; Chiang Mai region by characterizing both the ground mo- resistivity acquisition at Wiang Kum Kam; ground-penetrating radar tion amplifi cation and site response throughout the Chiang acquisition with temple monk observers at Wat Pan Sao; Hoai Trung Mai-Lamphun Basin. Additionally, we identify and charac- Dang collects magnetic data at Wat Pan Sao. terize faults that may be active. Lastly, we select archaeological sites of historic signifi cance to identify and characterize resistivity, electromagnetic, and gravity data in profi le to map buried structures that may provide important insights into stratigraphy, geologic structures, and hydrogeologic bound- past cultures. aries in a basin dominated by tilted Tertiary strata overlying metamorphic basement rocks (e.g., Morley et al., 2001; Gris- Groundwater characterization at Mae Hia semann et al., 2004; Rhodes et al., 2005). Mae Hia, an abandoned landfi ll, is presently an agriculture We acquired fi ve resistivity profi les throughout the Mae research center for Chiang Mai University. Th e 517-acre site Hia campus (Figure 3). Near-surface conductive zones identi- is approximately 5 km south of Chiang Mai, located within fi ed on resistivity profi les represent fl uvial deposits shed from one of the highest groundwater exploitation areas of the re- adjacent foothills with a water-table transition zone identi- gion, and is highly vulnerable to groundwater pollution (e.g., fi ed in the upper few meters below land surface. Time-do- Margane and Tatong, 1999). We acquired seismic refl ection, main electromagnetic and gravity profi les identify the general

Institute Instructor Boise State University (USA) Lee Liberty, Spencer Wood, Kasper vanWijk Graduate students: Emily Hinz, Dylan Mikesell, Shaun Finn, Th omas Blum, Katie Decker Chiang Mai University (Th ailand) Fongsaward Singharajawarapan, Suwimon Udphuay, Sarawute Chantraprasert, Siriporn Chaisri, Chanpen Silawongsawat Department of Mineral Resources (Th ailand) Apichart Paiyarom, Kachentra Neawsuparp, Wachirachai Sakapa, Tanad Soisa Geonics Limited (Canada) Rob Harris Royal Irrigation Department (Th ailand) Noppadol Poomvises Th e University of Western Australia Jeff rey Shragge Table 2. Instructors from 2010 and 2011.

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Figure 3. (a) Aerial photograph from Mae Hia with geophysical line locations. Gravity, EM-57, and seismic data from profi le A-A’. (b) Gravity profi le with observed and calculated measurements providing a fi rst-order estimate of basin thickness. (c) EM-57 profi le and measurements show increasing thickness of resistive basin sediments overlying a more conductive basement. (d) Seismic refl ection profi le shows a shallow water table and northwest-dipping Tertiary strata overlying a low-angle Paleozeoic basement. (e) Interpretive cross section across the Chiang Mai basin (from Rhodes et al., 2004) with interpreted low-angle faults separating Tertiary strata from older basement rocks. Red box represents area imaged with gravity, EM-57, and seismic refl ection methods during our study. basin confi guration while a 48-channel seismic refl ection pro- a maximum width of about 45 km, a length of over 130 km, fi le characterizes the east-dipping bedrock surface, overlying and an area of about 3000 square km (Figure 1). As a com- west-dipping Tertiary strata, and low-angle faults (Figure 3). ponent of the fi eld training, we collect multichannel surface Our results show that high-quality geophysical results can be wave (MASW) data to determine shear-wave seismic veloci- obtained with equipment available in Th ailand and are being ties in the upper 30 m (VS30 measurements) at many sites used to better constrain groundwater and structural models throughout the basin and along an earthen dam (Poomvises for the Chiang Mai Basin to address contaminant fl ow. Fu- et al., 2010). Th ese values can provide estimates of site am- ture studies using our geophysical methodologies are being plifi cation from local or regional earthquakes (e.g., Park et planned for other portions of Chiang Mai and nearby ba- al., 1999). Near-surface materials at these fi eld sites contain sins to characterize groundwater, stratigraphy and geologic a range of lithologies and velocity values that can provide structures. Data integration between geophysical methods a foundation for a probabilistic hazard map for the region provides key insights to provide a geologic and hydrogeologic (Figure 4). framework for the Mae Hia region. In addition to MASW measurements, participants acquire seismic refl ection, seismic refraction, electromagnetic, Hazards studies magnetic, and gravity data along profi les within the Chiang Th e Chiang Mai-Lamphun Basin is one of several inter- Mai Basin. Additionally, in 2010 we installed a broadband mountain graben and half-graben rift basins that comprise seismometer to characterize local ground motion from re- the northern Th ailand Basin and Range Province (e.g., Mor- gional earthquakes. We interpret basin structure, characterize ley et al., 2001; Rhodes et al., 2005; Figure 3). Th e basin has the transition between modern fl uvial deposits and Tertiary

416 The Leading Edge April 2011 Geoscientists Without borders

walls and where additional walls were suspected. In addition to tracking buried walls using geophysical methods, an old levee system was identifi ed and charac- terized using ground-penetrating radar and resistivity results (Hinz et al., 2010). Our survey was the fi rst documented high-resolution geophysical survey of a levee system that defi nes the extent of the ancient city of Wiang Kum Kam. Wat Pan Sao is the site of a present- day temple within Chiang Mai where ancient walls and structures were un- earthed during excavation (Figure 2). At this second archaeology fi eld site, participants identify modern utilities using ground-penetrating radar or magnetic data acquired within the temple grounds along with geophysical anomalies that may represent historical features of signifi cance. Additionally, we identifi ed buried walkways or walls from a seismic survey, using both seismic refl ection and refraction results (Hinz et al., 2010). As a result of our study, archaeologists have gained new insights into the Wat Pan Sao temple grounds and have identifi ed sites that may warrant further study. Addi- tionally, we are exploring new geophysi- Figure 4. (a) Seismic source used for MASW, refraction, and refl ection acquisition; (b) cal methods and procedures to work in seismic shot gather used for MASW analysis; (c) dispersion curve comparing phase velocity and areas of extensive cultural noise. frequency; (d) P-wave (green) and S-wave (gray) velocity profi le derived from dispersion curve for the upper 50 m; (e) S-wave velocity profi le from MASW records at Mae Hia. Data analysis After completion of the fi eld phase, par- marine strata, and identify fault locations that may pose risks ticipants focus their eff orts on the analysis of geophysical to northern Th ailand. Th ese data will be integrated into a re- data from each site. Analysis and interpretation take place gional database to improve the hazard assessments for earth- at the Geological Sciences Department of Chiang Mai Uni- quake damage from regional events. GWB participants are versity. Here, we divide participants into groups. Each group continuing the use of MASW and other geophysical methods works on geophysical theory, fi eld methods, and interpreta- for related hazards studies using the knowledge and methods tion for seismic, potential fi elds, resistivity, electromagnetic, from the fi eld school. and ground-penetrating radar data, to prepare incremental oral reports to the other participants. Much of the data anal- Archaeology studies ysis is performed using free and/or readily available software Wiang Kum Kam, a 13th-century settlement in the Chiang so that each participant can analyze the data sets without Mai region, was abandoned due to repeated fl oods of the commercial restrictions. A team also works on data archival Ping River. After the establishment of Chiang Mai, Wiang and data and report integration. Participants present the re- Kum Kam continued to exist as a satellite town to the new sults to the Chiang Mai University communities and prepare Lanna capital until the end of the Mangrai Dynasty. Archae- a fi nal integrated report that is available to the science and ological remains, such as stone tablets with Mon inscriptions, local community. Field data, processed results, fi eld photos, pottery, and earthenware molds have been excavated at sites methods, publications, and public domain software from the around Wiang Kum Kam over the past 20 years; however, fi eld camp are posted at http://cgiss.boisestate.edu/gwb. the extent of the city walls and structures is unknown (e.g., Wood et al., 2004). Summary Participants acquired ground-penetrating radar, magnet- Training directed toward student and geoscience profession- ic, and resistivity data to identify and characterize abandoned als has resulted in an increased use of fi eld-based geophysics channels of the Ping River and old temple brick walls (Figure throughout Southeast Asia. Our GWB-funded project pro- 5). Geophysical surveys were carried out above known brick vides a mechanism to link personnel, geophysical equipment,

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Figure 5. (a) Site map for Wiang Kum Kam Morley, C. K., N. Woganan, N. Sanku- showing Ping River, and a network of modern roads marn, T. B. Hoon, A. S. Alief, and M. and buildings. Inset map shows survey and location Simmons, 2001, Late Oligocene-recent of paleochannel that likely infl uenced the partial stress evolution in rift basins of northern burial of Wiang Kum Kam. (b) Parallel resistivity and central Th ailand: implications for profi les showing lateral contrasts in the coarse- and escape tectonics: Tectonophysics, 334, fi ne-gained sediments along the paleo-Ping River 115–150. channel. Resistive river sands contrast overbank Park, C. B., R. D. Miller, and J. Xia, deposits of the Ping River. (c) Seismic refraction 1999, Multichannel analysis of surface profi le showing low-velocity unsaturated channel deposits contrasting with the saturated fi ne-grained waves (MASW): Geophysics, 64, no. 3, overbank deposits. (d) Ground-penetrating radar 800–808, doi:10.1190/1.1444590. profi le showing a levee separating coarse- and fi ne- Poomvises, N., A. Kongsuk, L. M. Lib- grained deposits of the paleo Ping River channel. erty, T. D. Mikesell, and A. Satitpittakul, 2010, Multichannel analysis of surface waves, an application to diagnose the dam body: 5th International Conference on Applied Geophysics, Phuket, Th ailand. Rhodes, B. P., R. Perez, A. Lamjuan, and S. Kosuwan, 2004, Kinematics and tectonic implications of the Mae Kuang Fault, northern Th ailand: Journal of Asian Earth Sciences, 24, no. 1, 79–89, doi:10.1016/j.jseaes.2003.09.008. Wood, S. H., L. M. Liberty, F. S. Sing- harajwarapan, T. Bundarnsin, and E. Rothwell, 2004, Feasibility of gradient magnetometer surveys of buried brick structures at 13th Century (C. E.) Wi- ang Kum Kam, Chiang Mai Province, Th ailand, in S. Rieb, P. Wongpornchai, and S. Chantraprasert (eds) Proceedings and expertise together for an intensive two-week training to of the International Conference on Applied Geophysics, Chiang address groundwater, archaeology, and geohazards problems. Mai: Department of Geological Sciences, Chiang Mai University, Th e skills that were learned and refi ned during these train- 22–30. ings are having a lasting impact throughout the region via Acknowledgments: Th is geophysics workshop could not have been student theses and professional projects that are currently possible without the support of many organizations and individuals. underway. Additional training is scheduled beyond GWB We greatly appreciate the generous fi nancial contributions made by support where new surveys will benefi t not only geophys- SEG’s Geoscientists Without Borders program, our primary sponsor. ics participants but also the wider community through an In addition to the SEG fi nancial support, signifi cant contributions increased understanding and focus on archaeological sites, were provided by Boise State University, Chiang Mai University, groundwater infrastructure, and hazard assessments. Colorado School of Mines, Th ailand Department of Mineral Re- References sources, Geonics Limited, Royal Irrigation Department of Th ailand, Colorado School of Mines, Boise State University and Imperial Col- Th e University of Western Australia, and many individuals within lege, 2010, Characterization of the Upper Arkansas River Basin this group that provided time, eff ort, and personal funds to make geophysics fi eld camp report: http://pal.boisestate.edu/mediawiki/ this fi eld training a success. Seismic, gravity, magnetic, electromag- index.php/Field_camp. netic, and resistivity equipment used during these trainings were Grissemann, C., A. Schuck, K. Seidel, G. Lange, and W. Tantiwanit, provided by Boise State University, Chiang Mai University, Th ai- 2004, Geophysical signatures of the abandoned waste disposal sites land Department of Mineral Industries, Th ailand Royal Irrigation Mae Hia and Nog Harn, Chiang Mai., in S. Rieb, P. Wongporn- Department, Mahidol University, Siam Tone Company Limited, chai, and S. Chantraprasert (eds), Proceedings of the International Conference on Applied Geophysics, Chiang Mai: Department of and University of Western Australia. Additionally, we wish to thank Geological Sciences, Chiang Mai University, 50–59. Chiang Mai University, the Chiang Mai Offi ce of Archaeology and Hinz, E., L. M. Liberty, S. H. Wood, F. Singharajawarapan, S. National Museum, Th e Fine Arts Department, and the Chief Monk Udphuay, A. Paiyarom, and J. Shragge, 2010, Student-based ar- of Wat Pan Sao for site access and historical documents. chaeological geophysics in northern Th ailand: 80th Annual In- Corresponding author: [email protected] ternational Meeting, SEG, Expanded Abstracts, 3848–3852, doi:10.1190/1.3513651. Editor’s note: Geoscientists Without Borders is a registered trademark Margane, A., and T. Tatong, 1999, Aspects of the hydrogeology of the of SEG Foundation. Chiang Mai-Lamphun basin, Th ailand that are important for the groundwater management: Zeitschrift fuer Angevandte Geologie, 45, 188–197.

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