Understanding Mountain Landscapes

I am interested in understanding how mountain hazards are linked to mountain building processes, continental deformation rates and erosion. To do that, I use an extensive toolset (such as GPS geodesy, geochronology and terrestiral remote sensing) to investigate spatial and remporal patterns of deformation and erosion in the Himalaya-Tibet orogen and European Alps. Below are summaries of my main projects.

European Alps

I use terrestrial remote sensing (LiDAR) to detect and monitor rockfall activity in deglaciated alpine valleys located in the Swiss Alps. Using terrestrial laser scans data, I calculate rockwall retreat rates We used three different approaches to determine retreat rates over different time scales to understand rockwall retreat rates under present-day conditions and their temporal change since deglaciation.

For more information on this research please see:

Mohadjer, S., Ehlers, T.A., Nettesheim, M., Ott, M.B., Glotzbach, C., and Drews, R., 2020. Temporal variations in rockfall and rockwall retreat rates in a deglaciated valley over the last 11 ka. Geology, v. 48 (Download PDF)

Dietze, M., Mohadjer, S., Turowski, J. M., Ehlers, T. A., and Hovius, N., 2017. Seismic monitoring of small alpine rockfalls - validity, precision and limitations, Earth Surf. Dynam. 5, 653-668. (Download PDF)

India-Asia Orogen

My two recent projects related to the India-Asia orogen aim to (1) improve access to Quaternary fault information through a web-based interactive map and an online database (access database here) and (2) compare deformation rates from different techniques (geologic vs geodetic) to understand transients in, and pertinent timescales of, mountain building and erosional processes.

For more information on this research please see:

Mohadjer, S., Ehlers, T.A., Bendick R., Mutz, S.G., 2017. Review of GPS and Quaternary fault slip rates in the Himalaya-Tibet Orogen, Earth-Science Reviews, 174, pp. 39-52 (Download PDF)

Mohadjer, S., Ehlers, T. A., Bendick, R., Stübner, K., and Strube, T., A Quaternary fault database for central Asia, 2016. Natural Hazards and Earth System Sciences, 16, 529-542, doi:10.5194/nhess-16-529-2016. (Download PDF)

Pamir & Hindu Kush

I use geodetic observations to understand where and how convergence between the NW corner of the Indian plate and Asia is accomodated within the Pamir, Hindu Kush and the surrounding regions. Results of our work has allowed us to constrain the regional kinematics, including slip rates on large faults.

For more information on this research please see:

Perry, M., Kakar, N., Ischuk, A., Metzger, S., Bendick, R., Molnar, P., and Mohadjer, S., 2018. Little Geodetic Evidence for Localized Indian Subduction in the Pamir-Hindu Kush of Central Asia, Geophysical Research Letters, v. 46, pp. 109-118 (Download PDF)

Ischuk, A., Bendick, R., Rybin, A., Molnar, P., Khan, S.H., Kuzikov, S., Mohadjer, S., Saydullaev, U., Ilyasova, Z., and Schelochkov, G., Kinematics of the Pamir and Hindu Kush regions from GPS geodesy, 2013. Journal of Geophysical Research Letters- Solid Earth, Vol. 118, 1-9 PP (Download PDF)

Mohadjer, S., Bendick, R., Ischuk, A., Kuzikov, S., Kostuk, A., Saydullaev, Lodi, S., Kakar, D.M., Wasy, A., Khan, M.A., Molnar, P., Bilham, R., and Zubovich, A.V., 2010. Partitioning of India-Eurasia convergence in the Pamir-Hindu Kush from GPS measurements, Geophysical Research Letters, Vol. 37, L04305, 6 PP. (Download PDF)

Western Tian Shan

My work in the Western Tian Shan (Tajikistan) focuses on understanding the topographic response to tectonic, lithologic and climatic variations over millennial timescales. To do that, I calculate catchment-wide denudation rates with in situ-produced cosmogenic 10Be of samples from active river channels in the Western Tian Shan including the Fann mountains.

More information on this research will be available soon:

Mohadjer, S., Ratschbacher, L., Ehlers, T.A., Abdulov, S., Gadoev, M., Oimahmadov, M., Schaller, M., 2020 (in prep). Along-strike variations in cosmogenic derived denudation rates in the Western Tian Shan, Tajikistan. Geomorphology