Edwin Nissen
   Research Projects
Some current topics of focus are listed below. 

Rupture complexity in large earthquakes
Recent advances in geodetic and seismological imaging (including those described in the next project) provide powerful new insights into the rupture process of large earthquakes. We have used these tools to investigate patterns of shallow slip, off-fault deformation and fault segmentation in several recent earthquakes. These rupture characteristics are of critical importance for earthquake physics, for interpreting paleoseismic data, and for forecasting future earthquakes. One of our most interesting observations has been cascading earthquakes that "jump" from fault to fault across wide (~10s of km) segment boundaries, which was not previously thought possible.

Some key papers:

Clark, K. J., Nissen, E. K., Howarth, J. D., Hamling I. J., Mountjoy, J. J., Ries, W. F., Jones, K., Goldstien, S., Cochran, U. A., Villamor, P., Hreinsdóttir, S., Litchfield, N. J., Mueller, C., Berryman, K. R., and Strong, D. T. (2017). Highly variable coastal deformation in the 2016 Mw 7.8 Kaikōura earthquake reflects rupture complexity along a transpressional plate boundary. Earth and Planetary Science Letters, 474, 334-344.   

Nissen, E., Elliott, J. R., Sloan, R. A., Craig, T. J., Funning, G. J., Hutko, A., Parsons, B. E., and Wright, T. J. (2016). Limitations of rupture forecasting exposed by instantaneously triggered earthquake doublet. Nature Geoscience, 9, 330-336.    

Differential lidar
Repeat high-resolution topographic data offer the capability to map earthquake surface displacements at high spatial resolution, in three dimensions, and without loss of coherence even amongst steep deformation gradients close to surface faulting. We have developed and are applying these emergent techniques to characterize shallow slip in the first wave of earthquakes spanned by "before" and "after" lidar topography, including notable events in Japan, California, and New Zealand.

Some key papers:

*Lajoie, L., Nissen, E., *Johnson, K. L., Arrowsmith, J R., Glennie, C. L., Hinojosa‐Corona, A., and Oskin, M. E. (2018). Extent of low‐angle normal slip in the 2010 El Mayor‐Cucapah (Mexico) earthquake from differential lidar. Journal of Geophysical Research: Solid Earth, 123, doi: 10.1029/2018jb016828.

Scott, C., Arrowsmith, J R., Nissen, E., *Lajoie, L., Maruyama, T., and Chiba, T. (2018). The M7 2016 Kumamoto, Japan, earthquake: 3D deformation along the fault and within the damage zone constrained from differential topography. Journal of Geophysical Research: Solid Earth, 123, 6138-6155.

Nissen, E., Maruyama, T., Arrowsmith, J. R., Elliott, J. R., Krishnan, A. K., Oskin, M. E., and Saripalli, S. (2014). Coseismic fault zone deformation revealed with differential lidar: examples from Japanese Mw ~7 intraplate earthquakes. Earth and Planetary Science Letters, 405, 244-256.   

Where it all started:

Nissen, E., Krishnan, A. K., Arrowsmith, J. R., and Saripalli, S. (2012). Three-dimensional surface displacements and rotations from differencing pre- and post-earthquake LiDAR point clouds. Geophysical Research Letters, 39, L16301.  

Active tectonics of northwestern North America
The tectonics of western British Columbia and its neighboring regions provide an assortment of intriguing targets for study. From South to North, these include (1) the role of upper plate faulting (newly identified in lidar imagery) in deformation of the Cascadia forearc; (2) patterns of strain accumulation and release on the Cascadia megathrust, as will soon be revealed using sea-floor geodesy; (3) plate boundary reorganization offshore northern Vancouver Island; (4) the Queen Charlotte fault, the world's foremost ocean-continent transform boundary; and (5) diffuse deformation across the broad Yakutat collision zone. Over the next few years I hope that we will make contributions in all these areas - watch this space!

Active tectonics and earthquake hazards in the Middle East
Located within the Arabian-Eurasia plate boundary zone, Turkey and Iran contain a dense concentration of large-magnitude earthquakes, including several of the most damaging ever recorded. By studying recent earthquake sequences using high-resolution earthquake relocations, waveform modelling and InSAR, we are investigating continental extensional (Western Turkey) and collisional (Iran) tectonics and patterns of seismicity, aftershocks, and triggering.

Some key papers:

*Karasözen, E., Nissen, E., Büyükakpınar, P., Cambaz D., Kahraman, M., Kalkan, E., Abgarmi, B., Bergman, E., Ghods, A., and Özacar, A. A. (2018). The 2017 July 20 Mw 6.6 Bodrum-Kos earthquake illuminates active faulting in the Gulf of Gökova, SW Turkey. Geophysical Journal International, 214, 185-199.

Howell, A., Jackson, J., Copley, A., McKenzie, D., and Nissen, E. (2017). Subduction and vertical coastal motions in the eastern Mediterranean. Geophysical Journal International, 211, 593-620.   

Nissen, E., Tatar, M., Jackson, J. A., and Allen, M.B. (2011). New views on earthquake faulting in the Zagros fold-and-thrust belt of Iran. Geophysical Journal International, 186, 928-944.

Active faulting in Mongolia

Mongolia lies within the northernmost India-Eurasia collision zone and has hosted several of the largest continental ruptures ever recorded. It contains a dense network of active faults that are clear in satellite imagery but whose individual slip rates and earthquake chronologies are poorly known. We are using field work, sampling and Quaternary dating to determine active fault slip-rates within the Mongolian Altay mountains, in turn helping illustrate its unusual mode of shortening (anastomosing strike-slip faults and vertical-axis block rotations). A bonus of this work has been new age constraints on alluvial fan aggradation and regional Quaternary paleoclimate.

Some key papers:

Walker, R. T., Wegmann, K.W., Bayasgalan, A., Carson, R. J., Elliott, J., Fox, M., Nissen, E., Sloan, R. A., Williams, J. M., and Wright, E. (2017). The Egiin Davaa prehistoric rupture, central Mongolia: a large-magnitude normal faulting earthquake, on a reactivated fault with little cumulative slip, in a slowly-deforming intraplate setting. In “Seismicity, Fault Rupture and Earthquake Hazards in Slowly Deforming Regions” (eds. Landgraf, A., Stein, S., and Hintersbergen, E.), Special Publication of the Geological Society of London, 432, 187-212.  

Nissen, E., Walker, R., Bayasgalan, A., Carter, A., Fattahi, M., Molor, E., Schnabel,  C., West, A. J., and Xu, S. (2009). The late Quaternary slip-rate of the Har-Us-Nuur fault (Mongolian Altai) from Cosmogenic 10Be and Luminescence dating. Earth and Planetary Science Letters, 286, 467-478.  

Walker R., Nissen, E., Molor, E., and Bayasgalan, A. (2007). Reinterpretation of the active faulting in central Mongolia. Geology, 35, 759-762.