With sequence stratigraphic concepts and a modicum of understanding of the regional tectonic history, your 3D seismic cube can begin revealing its secrets. Before we delve into this further, it’s important to remember that by far the most gracious method of understanding what comes out of the data, is to look at the world around us. All the depositional environments that have ever existed still exist today; as expounded by Charles Lyell in the early 1830s, the present is the key to the past.
In this sense, imagination is more important than knowledge (a quote from Einstein), and for those geophysicists who do not spend enough time in the real world, perpetually locked in the office, you must venture into Google Earth for a cut-price field trip. If you want to see some fluvio-glacial outwash channels, just go to Alaska. If you want to go see a nearshore bar, the west coast of Denmark is awesome:
Don’t forget nature, don’t forget scale, and keep it real. Nature has given you a cheat sheet to the subsurface exam!
With this in mind, you’re now armed with a dangerous skill set. Once you’ve got some sequence boundaries mapped out, you can start the detective work. Thickness variation and seismic truncations, once you have accounted for structural elements, will guide you to deductions about relative sea-level. Push the seismic data to its limits; forget about specific attributes, just run as many as you can, because you may see something interesting, and even the absence of something interesting is information in itself! Give your data an MRI scan: run a spectral decomposition tool which can unlock hidden information. Target your analysis and try not to cut across too many onsets; you need to be parallel to reflections as much as possible to visualize bedform patterns on palaeoslopes.
Remember to use unfiltered, high-fidelity data where possible, and be realistic when it comes to your stratigraphy. For example, if you have a hard chalk sequence above your target zone, you can kiss some of the high frequency content goodbye. If you can, co-rendering attributes in a volumetric visualization will give a big advantage.
Immerse yourself in the geology that shape-shifts the world around us. Whenever you are on a beach, by a river, or flying 10,000 metres above the ground, you can gain increased understanding of the subsurface. It’s so easy to lose sight of what you’re working on in the office and field trips may be infrequent. So, take five, and Google away.