Project Overview
Fault scarps represent some of the most dynamic landscapes on Earth, where tectonic forces create topographic relief that drives complex sediment transport processes. This project investigates the intricate relationship between tectonic activity and landscape evolution by analyzing sediment transport processes along rocky fault scarps using advanced field observations and numerical modeling techniques.
Scientific Background
Rocky fault scarps are natural laboratories for understanding the interplay between tectonics and surface processes. Unlike sedimentary environments, rocky scarps present unique challenges for sediment transport due to:
- Highly variable rock strength and fracture patterns
- Complex topography with steep gradients
- Episodic sediment supply from rockfall and weathering
- Competing processes of erosion and deposition
Research Objectives
- Quantify sediment flux rates along fault scarps of varying ages
- Characterize erosion patterns and mechanisms in rocky environments
- Develop predictive models for landscape evolution
- Understand the role of climate variability in scarp degradation
- Assess long-term stability of fault scarp morphology
Methodology
Field Observations:
- High-resolution topographic surveys using terrestrial LiDAR
- Rock strength measurements and joint pattern analysis
- Sediment sampling and grain size distribution analysis
- Cosmogenic nuclide dating of exposed surfaces
- Long-term monitoring with automated instrumentation
Numerical Modeling:
- Cellular automata models for rockfall simulation
- Finite element analysis of stress-induced fracturing
- Sediment transport modeling using modified Hjulström curves
- Landscape evolution models incorporating fault displacement
- Coupled hydro-mechanical modeling of weathering processes
Remote Sensing Applications:
- Multi-temporal satellite imagery for change detection
- UAV-based photogrammetry for detailed surface mapping
- Thermal infrared imaging for rock fracture identification
- Ground-penetrating radar for subsurface structure analysis
Study Areas
Southern California Fault Systems:
- San Andreas Fault - Carrizo Plain segment
- San Jacinto Fault Zone - crystalline bedrock exposures
- Elsinore Fault - varying lithology contrasts
- Garlock Fault - arid environment end-member
Comparative Study Sites:
- Basin and Range Province - Nevada normal fault scarps
- Eastern Mediterranean - Dead Sea Transform
- New Zealand - Alpine Fault system
- Turkey - North Anatolian Fault Zone
Key Research Questions
- How do sediment transport rates vary with scarp height and rock type?
- What controls the transition from transport-limited to weathering-limited erosion?
- How do climate fluctuations affect long-term scarp evolution?
- Can we predict scarp morphology from tectonic and climatic parameters?
- What is the role of extreme events in scarp degradation processes?
Expected Outcomes
- Empirical relationships between tectonics and erosion rates
- Improved landscape evolution models for rocky environments
- Hazard assessment tools for rockfall and debris production
- Paleoseismic applications using scarp morphology
- Climate change impacts on tectonic landscape stability
Broader Impacts
This research contributes to several important applications:
- Natural Hazards: Better prediction of rockfall and debris flow sources
- Infrastructure: Assessment of long-term slope stability
- Water Resources: Understanding sediment input to drainage systems
- Paleoseismology: Using scarp morphology to constrain earthquake timing
- Climate Studies: Quantifying feedbacks between tectonics and erosion
Collaboration & Funding
This project is supported by NSF EAR Geomorphology and Land-use Dynamics Program, with additional funding from USGS and international collaboration agreements. Research partners include UC Berkeley, Stanford University, and the GFZ German Research Centre for Geosciences.