New paper: Fill terrace formation and sediment signals

Publication

I am excited to see our new paper on alluvial channel response to environmental perturbations published today in Earth Surface Dynamics. In this paper we present results from physical experiments of channels that were subject to perturbations of water and sediment discharges. We demonstrate that combining terrace geometries with information on (1) the timescales of terrace formation and/or (2) the sediment discharge from the river system, allows to distinguish between water and sediment discharges as the driver for river incision.

Tofelde, S., Savi, S., Wickert A.W., Bufe, A., Schildgen, T.  (2019). Alluvial channel response to environmental perturbations: Fill-terrace formation and sediment-signal disruption. Earth Surface Dynamics, 7(2), 609-631. Journal Link

This is a schematic diagram of the changes expected in (a&b) river morphology and (c-f) the sediment output from an alluvial river during a transient phase of incision (a, c & e) or aggradation (b, d & f). Panels (c-f), show the upstream sediment input (orange line) and water input (blue line) and the downstream sediment output (colored circles). Importantly, a phase of incision can be due to a decrease in the sediment input into the channel, or an increase in the water input. The topography is similar in both cases but the pattern of sediment output is very different. Therefore, using sedimentary archives that record such sediment output together with terrace records can yield more information about the driver behind a change than each one of the records by itself.

EGU 2019

Conference

EGU is happening and I hope to see some of you there! This year, I will:

Co-convene a session
Erosion, chemical weathering and sedimentation in mountain landscapes
Orals: Wed, 10 Apr, 08:30–12:30, 14:00–15:45, Room D3.
Posters: Thu, 11 Apr, 08:30–10:15, Hall X2.

Give a solicited talk
Bufe et al. Temporal changes in rock uplift rates of folds in the foreland of the Tian Shan and the Pamir from geodetic and geologic data. Tue, 09 Apr, 17:45–18:00, Room K1. (Link)

Co-author talks
Roda-Boluda et al. Examining landslide recurrence intervals and landslide-derived sediment fluxes with 10Be concentrations and grain size distributions: preliminary results from the Fiordland and the Southern Alps, New Zealand. Wed, 10 Apr, 09:45–10:00 Room D3. (Link)

Tofelde et al. Fill-terrace formation and sediment-signal disruption in response to environmental perturbations. Wed, 10 Apr, 15:15–15:30, Room D3. (Link)

Hoffimann-Mendes et al. Morphodynamic Analysis and Statistical Synthesis of Geomorphic Data. Wed, 10 Apr, 16:15–16:30, Room 0.96. (Link)

New paper in open review: Fill terrace formation and sediment signals

Publication

River terraces hold information about perturbations in climate and tectonics, but different perturbations can have similar effects on the stratigraphic record. For example, both a decrease in sediment discharge or an increase in water discharge can cause river incision, which complicates the interpretation of incised terraces. In our new paper that is open for review and discussion in Earth Surface Dynamics, we present results from physical experiments of channels that were subject to perturbations of water and sediment discharges. We demonstrate that combining terrace geometries with information on (1) the timescales of terrace formation and/or (2) the sediment discharge from the river system, allows to distinguish between water and sediment discharges as the driver for river incision. You can have a closer look and discuss the paper here.

Tofelde, S., Savi, S., Wickert A.W., Bufe, A., Schildgen, T. Alluvial channel response to environmental perturbations: Fill-terrace formation and sediment-signal disruption. under review at Earth Surface Dynamics

Goldschmidt and AK Geomorph meetings 2018

Conference

I will be presenting our results on the impact of soil and landslide erosion processes on weathering at both Goldschmidt in Boston and the AK Geomorphologt meeting in Gießen.

Bufe, A., Emberson, R., Hovius, N., Caves Rugenstein, J.K., Hassenruck-Gudipati, H. (2018). Impact of soil and landslide erosion processes on coupled sulfide oxidation and carbonate weathering. Goldschmidt. Boston, USA.

Bufe, A., Emberson, R., Hovius, N., Caves Rugenstein, J.K., Hassenruck-Gudipati, H. (2018). The impact of soil and landslide erosion processes on carbonate and silicate weathering in southern Taiwan. Central European Conference on Geomorphology and Quaternary Sciences. Gießen, Germany.

EGU 2018

Conference

I will be at EGU again, and this year, we have a lot going on.

I will be chairing a session:
Chemical weathering, soil formation, and organic carbon mobilization across spatial and temporal scales.

I will present a talk on our work on lateral channel migration rates:
Bufe, A., Turowski, J.M., Burbank, D.W., Paola, C., Wickert, A.D., Tofelde, S. (2018). Controls on lateral channel mobility and the reworked area of active alluvial surfaces. EGU General Assembly. Vienna, Austria.

I will present a poster on our most recent water chemistry from southern Taiwan:
Bufe, A., Emberson, R., Hovius, N., Caves-Rugenstein, J.K., Hassenruck-Gudipati, H. (2018). Impact of soil and landslide erosion processes on chemical weathering. EGU General Assembly. Vienna, Austria.

Moreover, Jeff Prancevic will present new grain size data from landslides in New Zealand:
Prancevic, J.P., Roda-Boluda, D., Tofelde, S., Bufe, A., Hemingway, J.D. (2018). Sediment sizes produced by landslides in a threshold landscape. EGU General Assembly. Vienna, Austria.

New Paper: Lateral bedrock erosion rates in the Tian Shan foreland

Publication

In the foreland of the Tian Shan, rivers erode kilometer-wide platforms into folds that are rapidly uplifting. In our new paper, we show that the existence of these eroded surfaces implies that rivers must have changed the rate at which they migrate laterally by as much as an order of magnitude over timescales of thousands of years. Such large changes in the lateral erosion rate seem to occur in response to much smaller (less than order-of magnitude) changes in climate or tectonics. Get the full story in our new paper:

Bufe, A., Burbank, D.W., Bookhagen, B., Liu, L., Chen, J., Li, T., Thompson, J., Yang, H. (2017) Variations of lateral bedrock erosion rates control planation of uplifting folds in the foreland of the Tian Shan, NW China. Journal of Geophysical Research: Earth Surface, 122(12), 2431-2467. Journal Link

AGU 2017

Conference

Come and see my poster at AGU! I will present our findings on the controls of channel-wall heights on alluvial channel migration.

Bufe, A., Turowski, J.M., Burbank, D.W., Paola, C., Tofelde, S., Wickert, A.D. (2017). Experimental evidence for a control by channel-wall height on alluvial channel migration. AGU Fall Meeting Abstracts. New Orleans, LA, USA.

New Paper: Quaternary Tectonics in the Pamir-Tian Shan

Publication

Our study on the Quaternary Tectonics in the Pamir-Tian Shan convergence zone was just published in Tectonics. This study was spearheaded by my colleague Jessica A. Thompson Jobe and demonstrates the progressive basinward propagation of deformation in this active region.

Thompson Jobe, J.A., Li, T., Chen, J., Burbank, D.W., Bufe, A. (2017). Quaternary Tectonic Evolution of the Pamir-Tian Shan Collision Convergence Zone, Northwest China. Tectonics, 36(12), 1944-9194. Journal Link

New Paper: Uplift rate changes in the Tian Shan foreland

Publication

I am excited to announce that our paper on variations in uplift rates across folds and faults in the Tian Shan foreland was accepted in Geophysical Research Letters . We use a combination of satellite images and geologic data to track how deformation rates on structures in this very actively deforming part of the world have changed through time. Have a look, and let me know what you think!

Bufe, A., Bekaert, D.P.S., Hussain, E., Bookhagen, B., Burbank, D.W., Thomspon Jobe, J.A., Chen, J., Li, T., Liu, L., Gan, W. (2017) Temporal changes in rock-uplift rates of folds in the foreland of the Tian Shan from geodetic and geologic data. Geophysical Research Letters, 44(21), 10977-10987. Journal link and Web version