I study a reverse fault with several fault strands, each cutting different sediments (Holocene, Q3b, Q3, Q2). Am I allowed to sum each displacement related to each strand to get the cumulative displacement of that spot?
I know even older sediments can be disturbed during the recent seismic events.
Cumulative displacement is the total amount of movement that has occurred along a fault over time. It is an important measure for understanding the behavior of faults and for assessing the potential for future seismic activity. There are several methods for measuring cumulative displacement along a fault, including geological mapping, geodetic surveys, and borehole measurements. Geological mapping involves studying the exposed rocks along the fault to identify changes in their orientation and position. By comparing the relative positions of rocks on either side of the fault, researchers can estimate the amount of displacement that has occurred. This method is limited by the availability and accessibility of exposed rocks, as well as by the accuracy of the measurements. Geodetic surveys use satellite-based positioning systems to measure changes in the position of points on either side of a fault. This method can provide highly accurate measurements of displacement over time, but it requires specialized equipment and expertise. Borehole measurements involve drilling into the ground and inserting instruments to measure changes in the orientation and position of rocks along a fault. This method can provide detailed information about the structure and behavior of faults, but it is expensive and time-consuming. Overall, measuring cumulative displacement along a fault requires careful analysis of multiple data sources and may involve a combination of methods to achieve accurate results.
References: 1. USGS Earthquake Hazards Program: https://www.usgs.gov/natural-hazards/earthquake-hazards/science/earthquake-faults 2. Geological Society of America: https://www.geosociety.org/gsatoday/archive/22/4/article/i1052-5173-22-4-4.htm 3. National Science Foundation: https://www.nsf.gov/news/news_summ.jsp?cntn_id=300652&org=NSF&from=news 4. American Geophysical Union: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL077697 5. ScienceDirect: https://www.sciencedirect.com/science/article/pii/S0012821X18304419
By studying the displacement of a bed of rock on the two sides of a fault or thrust, you measure the result of thee movements along the fault over time. usually the faults move in sudden events releasing strains on the rocks. The movement indicated by the relative position of the two sides today is the product of all the movement that have taken place.
Stuart.