{"title":"The utilisation of ghost reflections retrieved by seismic interferometry for layer‐specific characterisation of the shallow subsurface","authors":"Faezeh Shirmohammadi, Deyan Draganov, Ranajit Ghose","doi":"10.1002/nsg.12275","DOIUrl":null,"url":null,"abstract":"Seismic interferometry (SI) retrieves the Green's function between two receiver locations using their recordings from a boundary of sources. When using sources and receivers only at the surface, the virtual‐source gathers retrieved by SI contain pseudo‐physical reflections as well as ghost (non‐physical) reflections. These ghost reflections are the results of the cross‐correlation or auto‐correlation of primary reflections from two different depth levels, and they contain information about the seismic properties of specific layers in the subsurface. We investigated the application of ghost reflections for layer‐specific characterisation of the shallow subsurface using SI by auto‐correlation. First, we showed the technique's potential using synthetic data for a subsurface model with a lateral change in velocity, a gradient in depth for velocity, a thickness change, and a velocity change of the target layer. Then, we applied the technique to shallow subsurface field data. We also focused on improving the retrieval of ghost reflections by removing the free‐surface multiples and muting undesired events in active‐source gathers before applying SI. Our results demonstrate that the ghost reflections can be used advantageously to characterise the layer that causes them to appear in the results of SI. Consequently, they can also provide valuable information for imaging and monitoring shallow subsurface structures.This article is protected by copyright. All rights reserved","PeriodicalId":49771,"journal":{"name":"Near Surface Geophysics","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2023-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Near Surface Geophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1002/nsg.12275","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Seismic interferometry (SI) retrieves the Green's function between two receiver locations using their recordings from a boundary of sources. When using sources and receivers only at the surface, the virtual‐source gathers retrieved by SI contain pseudo‐physical reflections as well as ghost (non‐physical) reflections. These ghost reflections are the results of the cross‐correlation or auto‐correlation of primary reflections from two different depth levels, and they contain information about the seismic properties of specific layers in the subsurface. We investigated the application of ghost reflections for layer‐specific characterisation of the shallow subsurface using SI by auto‐correlation. First, we showed the technique's potential using synthetic data for a subsurface model with a lateral change in velocity, a gradient in depth for velocity, a thickness change, and a velocity change of the target layer. Then, we applied the technique to shallow subsurface field data. We also focused on improving the retrieval of ghost reflections by removing the free‐surface multiples and muting undesired events in active‐source gathers before applying SI. Our results demonstrate that the ghost reflections can be used advantageously to characterise the layer that causes them to appear in the results of SI. Consequently, they can also provide valuable information for imaging and monitoring shallow subsurface structures.This article is protected by copyright. All rights reserved
期刊介绍:
Near Surface Geophysics is an international journal for the publication of research and development in geophysics applied to near surface. It places emphasis on geological, hydrogeological, geotechnical, environmental, engineering, mining, archaeological, agricultural and other applications of geophysics as well as physical soil and rock properties. Geophysical and geoscientific case histories with innovative use of geophysical techniques are welcome, which may include improvements on instrumentation, measurements, data acquisition and processing, modelling, inversion, interpretation, project management and multidisciplinary use. The papers should also be understandable to those who use geophysical data but are not necessarily geophysicists.