Vertical exaggeration of reflection seismic data in geoscience publications 2006-2010

Reflection seismic data is widely-used in industry and academia. It is often interpreted and displayed with considerable vertical exaggeration. Vertical exaggeration is defined as the vertical to horizontal aspect ratio of a reflection seismic cross section in depth. Recent literature is reviewed here to quantify for the first time the extent and typical values of vertical exaggeration in published work. Results are collated from 1437 papers published in 68 journals in the period 2006-2010. This broad scope is intended to provide a global view but it does not claim to be exhaustive. One example from each paper was analysed. Depth conversion was necessary in 74% of cases (every case of time-domain seismic with vertical exaggeration not stated). The main findings are that only 12% of papers use aspect ratios with vertical scale set approximately equal to horizontal scale (vertical exaggeration in the range 0.8-1.2). 75% of papers use reflection seismic with vertical exaggeration greater than 2. Splits of the data in terms of shallow high resolution seismic and deep, crustal imaging seismic were also obtained. The cause of this very widespread vertical exaggeration of reflection seismic cross sections is generally some form of display optimisation, such as emphasis of stratigraphic architectures or displaying long sections that would otherwise not fit on screen, or effects related to seismic sampling, but a specific reason is rarely stated. Angular relationships in stratigraphic and structural architectures are distorted so commonly that true geometries are rarely seen, which becomes an issue if readers are unfamiliar with these geometries. There is a clear opportunity for authors who display and publish reflection seismic data to annotate an estimate of vertical exaggeration alongside other standard annotation on seismic displays.