This is the slighlty modified text of a Faculty Grant-in-aid proposal that I wrote for this project.


Active Faulting in the Pamir Mountains, Kyrgyzstan: Initiation of Collaborative Research

Ramón Arrowsmith, Department of Geology, Arizona State University

9 October, 1995

Statement of Problem and Objectives

Summary

This project will develop a research program on active earthquake deformation of the northern foothills of the Pamir Mountains, Kyrgyzstan with European colleagues to address basic problems in the formation of large mountain belts and applied problems in the mitigation of earthquake hazards.

Problems

Along leading edge of the Pamir Mountains is a fault system that accommodates some of the deformation associated with the collision of India with Eurasia. Because of the arid environment, lack of human degradation of the landscape, spectacular exposures of the effects of recent earthquakes and of the uplift of the mountain, this area is a premier natural laboratory for the investigation of the following significant problems:

1) As India has collided with Eurasia over the last 40 million years, the deformation has spread to the interior of Eurasia, uplifting Tibet, and driving faulting as far north as Lake Baikal. The collision and this deformation continue today (e. g., Molnar and Tapponnier, 1975). The partitioning of that deformation among the different blocks and their bounding faults in both space and time is an outstanding question in our understanding of large-scale continental deformation.

2) We assume that earthquakes and their associated secondary deformation are the quantum deformation events by which most mountain building occurs: if enough earthquakes are repeated, they will accommodate the large scale continental deformation, mountains will be built, and rocks will be permanently deformed. By investigating an area where active deformation in the form of earthquakes occurs as well as where the longer term deformation is evident in the nearby mountain range, we may substitute space for time, and investigate how the short term deformation is accumulated into longer-term mountain growth (a similar example is the work presented in Bürgmann et al., 1994).

3) The earthquakes and associated geologic structures are analogous to those in the Los Angeles Basin such as that along which the devastating Northridge earthquake (e.g., Dolan et al., 1995). Similar structures exist in Caucasus, Indian and Nepal Himalayas. The proposed research will provide data on the geometry and rates of deformation of these types of structures as well as promote the development of computer mapping and modeling tools for their characterization. Therefore the results from this work may be applied to the characterization of the significant geologic hazard that these structures pose to the Los Angeles Basin.

History of the project

As a graduate student at Stanford University, I was able to develop new techniques (both field and computer-based) in the investigation of active faulting. Manfred Strecker (University of Potsdam) and Lothar Ratschbacher (University of Tübingen) were at Stanford University as visiting faculty, supported by prestigious Heisenberg Fellowships. They were aware of my research and interests and have invited me to join them in their ongoing research in the Pamirs (see Strecker et al., 1994a; Strecker et al., 1994b).

Research approach

Tools

Geographic Information Systems

A Geographic Information System (GIS) is defined as "An organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information" (ESRI, 1993). Any type of field data that is geographically referenced may be entered into the GIS database. These data may then be analyzed and the results displayed in the form of a map.

The principle advantage of a GIS over another type of database (i.e. FoxPro, Microsoft Excel, etc.) is that a GIS' information is spatially referenced. Not only can analyses be performed on data attributes, but the data's position may also be taken into consideration when performing the analyses. This provides a powerful tool for analyzing spatial distributions of different types of field data.

This tool will be used throughout the project. The development of extensive databases requires sustained effort, and the return on the investment is maximized when the tool is used from the beginning.

Quantitative field methods

I expect to use high precision laser and Global Positioning System surveying equipment along with ground stereo photography to make detailed observations of the landforms and geologic structure along the mountain front. I have used similar methods to characterize the Landers, California earthquake surface rupture (Arrowsmith and Rhodes, 1994). These data will be recorded digitally where possible so that we may input them into the GIS easily on return.

Hillslope development models

This research provides the opportunity to apply and further develop models for determining the response of landforms to surficial deformation above active faults (Arrowsmith et al., 1995). This application will help us to develop models for interpreting the activity of active faults with direct utility in the characterization of earthquake hazard (and as such will be of interest to funding agencies such as the US Geological Survey).

Plan

This research will be accomplished by me and a student assistant in three stages: 1) Pre-field work database development, mountain-range scale morphometry and active tectonics analysis (following similar methods as (Bürgmann et al., 1994; Merritts and Vincent, 1989), but developing them using advanced Geographic Information Software), and identification of preliminary field work project targets; 2) Summer field work in the Pamirs (~3 weeks; the student will not participate in this stage); and 3) post fieldwork data compilation and external project proposal preparation. The proposed work would partially support all three stages.

Stage I: The GIS will be used to compile regional datasets such as Digital Elevation Models, remotely sensed imagery, earthquake catalogues, geophysical data. Preliminary range scale analyses and fieldwork planning/targets will be identified.

Stage II. Data will be collected in the field for direct input into the GIS. Data will include line, point, and elevation observations (detailed surveys, photo and observation locations, etc.). I expect that we will also do some reconnaissance for future projects (see Manfred's note).

Stage III. Post field trip data compilation and analysis will lead to a preliminary report (paper) in light of regional data set and hypothesis testing based upon field observations. I also expect to prepare follow-on phase II proposal, continuing collaboration, extending research area/problems, and adding student involvement (ideally one PhD). I envision a proposal to the National Science Foundation highlighting similar research questions as those identified here, but included more thorough field and modeling investigations that would run about $120 k/year and include 1 month summer support for me, full support for a graduate student, and appropriate funds for field investigations, computer analysis, consultation with collaborators, and presentation of results.

Start-up funds from the Department and the Dean permit me to buy hardware and software to support this research. I request a student assistant to help during stages I and III, especially during GIS database development.

Long-term impact

I expect that this project will provide the following results:

1) Data (in particular rates) and analysis on mountain building in Asia over time and its distribution on different structures

2) A better understanding of accumulation of permanent deformation by repeated earthquakes.

3) Tools and knowledge useful for the identification of active faults with direct application to hazard characterization.

3) Collaboration with internationally recognized colleagues helps me develop my research program in this field (previous reviewer comments have indicated that it was time for me to expand to field areas beyond California), and provides ASU international visibility. I also expect to gain experience in the observation of active faults and to appreciate the logistical challenges inherent in international field campaigns in remote areas.


References

Arrowsmith, J.R., and Rhodes, D.D., 1994, Original forms and initial modifications of the Galway Lake Road scarp formed along the Emerson fault during the 28 June 1992 Landers, California, earthquake: Bulletin of the Seismological Society of America, v. 84, p. 511-527.

Arrowsmith, R., Pollard, D.D., and Rhodes, D.D., 1995, A model for tectonic and geomorphic displacements applied to hillslope development in areas of active tectonics: Journal of Geophysical Research, Special Section on Paleoseismology, in press.

Bürgmann, R., Arrowsmith, R., Dumitru, T.A., and McLaughlin, R.J., 1994, Rise and fall of the southern Santa Cruz Mountains, California, from fission tracks, geomorphology, and geodesy: Journal of Geophysical Research, Special Section on Tectonics and Topography (AGU Chapman Conference), v. 99, p. 20,181-20,202.

Dolan, J.F., Sieh, K.E., Rockwell, T.K., Yeats, R.S., Shaw, J., Suppe, J., Huftile, G.J., and Gath, E.M., 1995, Prospects for larger or more frequent earthquakes in the Los Angeles Metropolitan region: Science, v. 267, p. 199-205.

Environmental Systems Research Institute (ESRI), Understanding GIS: the ARC/INFO Method. Longman Scientific & Technical. p.1-2, 1993.

Merritts, D., and Vincent, K.R., 1989, Geomorphic response of coastal streams to low, intermediate, and high rates of uplift, Mendocino triple junction region, northern California: Geological Society of America Bulletin, v. 101, p. 1373-1388.

Molnar, P., and Tapponnier, P., 1975, Cenozoic tectonics of Asia; effects of a continental collision: Science (AAAS), v. 189, p. 419-426.

Strecker, M.R., Ratschbacher, L., Frisch, W., Hamburger, M.W., Semiletkin, S., and Zamoruyev, A., 1994a, Quaternary deformation in the eastern Pamirs, Tadzhikistan and Kyrgyzstan, American Geophysical Union, 1994 fall meeting, Volume 75, No. 44, Suppl.: Eos, Transactions, American Geophysical Union: San Francisco, CA, USA, p. 631.

Strecker, M.R., Ratschbacher, L., Frisch, W., Semiletkin, S., and Zamoruyev, A., 1994b, Quaternary deformation in the eastern Pamirs (Kyrgizia & Tadzhikistan), Geological Society of America, 1994 annual meeting, Volume 26, No. 7: Abstracts with Programs - Geological Society of America: Seattle, WA, USA, p. 135-136.