Whether the seismic refraction inversion algorithms are sensitive to the either a discrete or smooth velocity gradient has yet to be explored, creating a source of uncertainty in the interpretation of seismic velocity profiles for the critical zone studies.
#Refraction – rayfract software
However, in these papers, there are often assumptions made about whether the velocity gradates smoothly or discretely across the various layers in the weathering profile. Our Rayfract® refraction tomography software allows reliable imaging of subsurface velocity structure including faults, strong lateral velocity variation and other velocity anomalies.Our Smooth inversion tomographic method is based on physically realistic modeling of first break propagation for P-wave and S-wave surveys. seismic refraction seismic tomography foundation studies surveys in fault and shear zones. In all of these studies, the authors were able to interpret their inverted seismic lines to produce meaningful observations about the critical zone. Because of this there are many examples of seismic refraction surveys in studies of the critical zone in mountainous watersheds (e.g. It has been particularly useful in identifying the depth to unaltered bedrock, which acts as the lower bound for water movement in the critical zone and so is of key importance (Freer et. There are many benefits to seismic refraction surveys as they are minimally invasive, can be applied over a large area and give information about the physical characteristics of the rock. Zelt, C.A., 2010, Seismic refraction shootout: blind test of methods for obtaining. Increasingly, geophysical methods such as seismic refraction are being used to make these large scale measurements.
Inability to distinguish between blocky and smooth gradients must be considered a significant source of uncertainty when utilizing such data, for example, to inform hydrologic models.Īs interest in the Critical Zone continues to grow, so too does the need for large scale measurements of its depth and physical properties. The synthetic inverted velocity profiles were found to be virtually indistinguishable, and in the blocky model the depth to consolidated bedrock was overestimated by 25%. RAYFRACT (was used to generate seismic compressional-wave velocity profiles. We simulate a seismic refraction experiment over smooth, semi-blocky and blocky velocity models of the critical zone, then pick traveltimes and invert with a commonly used commercial SRT package. The field records were input into the RAYFRACT seismic refraction tomography software developed by Intelligent Resources, Inc. We examine the ability of SRT to distinguish between blocky and smooth velocity models in a critical zone like setting. While SRT provides valuable information, it is important to recognize the limitations of this approach. Geophysical studies designed to investigate this region have increased in recent years and one of the commonly used tools is seismic refraction tomography (SRT). We utilize the term critical zone to denote the region near the surface of the earth that extends from the soil to the base of weathered rock.
0 kommentar(er)
