The flexural isostatic response of climatically driven sea-level changes on continental-scale deltas

The flexural isostatic response of climatically driven sea-level changes  on continental-scale deltas

Created by: Sara PolancoMike BlumTristan SallesBruce C. FrederickRebecca FarringtonXuesong DingBen MatherClaire MallardLouis Moresi

Submitted by: Sara Polanco

Submission date: August 28, 2023

DOIpending

Abstract

The interplay between climate-forced sea-level change, sediment erosion and deposition, and flexural adjustments in deep time on passive margin deltas remains poorly understood. We performed a series of conceptual simulations to investigate flexural isostatic responses to high-frequency fluctuations in water and sediment load associated with climatically driven sea-level changes. We model a large drainage basin that discharges to a continental margin to generate a deltaic depocenter, then prescribe synthetic and climatic-driven sea-level curves of different frequencies to assess flexural response. Results show that flexural isostatic adjustments are bidirectional over 100-1000 kyr timescales and are in sync with the magnitude, frequency, and direction of sea-level fluctuations, and that isostatic adjustments play an important role in driving along-strike and cross-shelf river-mouth migration and sediment accumulation. Our findings demonstrate that climate-forced sea-level changes produce a feedback mechanism that results in self-sustaining creation of accommodation into which sediment is deposited and plays a major role in delta morphology and stratigraphic architecture.

Publication

DOI10.5194/esurf-12-301-2024
Polanco, S., Blum, M., Salles, T., Frederick, B. C., Farrington, R., Ding, X., Mather, B., Mallard, C., & Moresi, L. (2024). Flexural isostatic response of continental-scale deltas to climatically driven sea level changes. Earth Surface Dynamics, 12(1), 301–320. DOI: 10.5194/esurf-12-301-2024

Tags

BadlandsPythondeltasdepositionerosionflexurefluvialsea-level

Graphic abstract

Graphic abstract | The flexural isostatic response of climatically driven sea-level changes  on continental-scale deltas

Licence

CC BY 4.0 DEED Attribution 4.0 International

CC BY 4.0: CC BY 4.0 DEED Attribution 4.0 International