EGU2020-9528
https://doi.org/10.5194/egusphere-egu2020-9528
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Geophysical insights on the internal dynamics of lahars from Lumbre channel, Volcán de Colima, Mexico

Braden Walsh1,2, Velio Coviello3, Lucia Capra4, Jonathan Procter5, and Victor Márquez-Ramirez4
Braden Walsh et al.
  • 1Department of Earth Sciences, Uppsala University, Uppsala, Sweden
  • 2Centre of Natural Hazards and Disaster Science, Uppsala University, Uppsala, Sweden
  • 3Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy
  • 4Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquila, Querétaro, México
  • 5Volcanic Risk Solutions, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand

Here, we present data from lahars through the use of a 3-component broadband seismometer, accelerometer, and a video camera installed 3 m from the Lumbre channel on Volcán de Colima, Mexico to understand rheology differences within multiple events, which occurred in late 2016. We used a combination of peak frequency content, directionality, and video analysis to determine rheology changes amongst the multiple events. Our findings show that different peak frequency patterns in each seismic component correspond to differing rheologies and flow processes. For instance, in the vertical and flow parallel directions the transition from streamflow to lahar coincides with a narrow frequency distribution to wide. Conversely, the cross-channel frequency content is opposite with streamflow portraying a wide frequency distribution transitioning to a narrow distribution with the lahars. Furthermore, there is a drop in overall peak frequencies when transitioning from streamflow to lahar. The directionality ratios computed further yielded evidence for a rheologic change between streamflow and lahar. Directionality ratios >1 were calculated for each lahar, and <1 for streamflow. We go on to show that componential analyses yielded channelization or freedom of movement in the cross-channel, bedload transport in the flow parallel, and channel geology in the vertical direction are possibly the main drivers in the peak frequency output of debris flows.

How to cite: Walsh, B., Coviello, V., Capra, L., Procter, J., and Márquez-Ramirez, V.: Geophysical insights on the internal dynamics of lahars from Lumbre channel, Volcán de Colima, Mexico, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9528, https://doi.org/10.5194/egusphere-egu2020-9528, 2020

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