On the layering artifacts in seismic imageries

Abstract

A common feature in seismic imageries of the crust and mantle is a layering pattern.Layering structures do exist in multiple scales, such as layered strata and unconformities in local and regional scales, and undulating seismic discontinuities in the crust and mantle. However, layering artifact also exists due to limitations in seismic processing and data coverage. There is a tendency for seis- mic stacking methods to over-map reflectors and scatters into along-isochron layers. In contrast, seismic tomography methods tend to under-map sub-horizontal layers with along-raypath smears and artifacts of various de-mean processes. To better identify signals and artifacts in seismic imageries, it isnecessary to understand the origins of various artifacts and make careful comparison between the solutions of different data and methods.

Reply to Comment by Pedreira et al. on “Reconstruction of the Exhumed Mantle Across the North Iberian Margin by Crustal‐Scale 3‐D Gravity Inversion and Geological Cross Section”

“…Bearing in mind the uncertainty in density values and based on previous seismic data (e.g., Pedreira et al, , ), we assumed as the initial gravity model a linear depth density variation for the crust between 2.67 g/cm 3 at surface and 2.95 g/cm 3 at 50 km (Torné et al, ). This linear depth‐dependent density increase avoids artificial horizontal interfaces within the crust, which commonly derive from seismic processing and modeling (e.g., Zhou, ).…”

Upper crustal structure beneath the northern South Yellow Sea revealed by wide‐angle seismic tomography and joint interpretation of geophysical data

“…Raypaths at depths greater than 10 km are very sparse and pass through the 10‐ to 15‐km depth interval vertically, turning at depth greater than 15 km. The steep, parallel raypaths at deep regions cause along‐raypath smearing of velocity anomalies (Zhou, ) but explain why horizontal resolution is better than vertical resolution at depths greater than 10 km.…”