Several years ago, my graduate students and I were mapping Wilcox Group coals, with well logs, in northern Louisiana for coalbed methane resources. Devon Energy supported a couple students mapping over areas where they had considerable leased acreage. We figured that the coals might be mappable with industry 3D data even though the coals are relatively shallow. We sought and were given the top two seconds of Devon’s 7 mi x 11 mi Latt Lake 3D in southern Winn and northern Grant parishes, which we incorporated into our mapping and demonstrated the ability to map the coals.

Later I assigned a student to investigate the entirety of the two seconds by flattening the volume and extracting seismic geomorphology throughout. He brought me an image from his flattened volume very near the base of the Midway Shale (Fig. 1) and asked me, “What is this?” My response was, “OMG.” I had been working on various aspects of the Chicxulub Impact, the end Cretaceous event, since 1994 and recognized that the image was of megaripples from the tsunami which resulted from the impact. The location of the impact and the seismic image are illustrated in Figure 2. Having recognized the tsunami megaripples we imaged the mega-ripples more clearly with a time-structure map (Fig. 3).

We published our research in Earth and Planetary Science Letters (Kinsland et al., 2021… all coauthors were graduate students).

We now are seeking access to two other 3D data volumes from which we have seen evidence of megaripples from the tsunami…the Bodcaw survey in northwestern Louisiana from which I have been granted, by Seismic Exchange Incorporated, two 2D lines that image megaripples, and the Bayou Boeuf survey in central Louisiana within which I glimpsed what I think are megaripple features, as Fairfield/CGG quickly previewed the data at a recent Lafayette Geological Society meeting. We presently are in negotiations to achieve access to these volumes. We expect to learn more about the characteristics of the megatsunami from these two data sets than we have from the single small Devon dataset.

I am here today to encourage you to help us. We need knowledge of 3D datasets that image the base of the Midway Shale in areas in which the Gulf of Mexico paleo-bathymetry was sharply shallowing. This tsunami was gulf wide. We are interested in access to 3D datasets anywhere around the Gulf of Mexico.

If a company owns the data, we will seek to work with the owner. If a broker, such as Seismic Exchange Incorporated, controls the data, we will seek permission from the broker to allow us to work within a company that presently has access to the data. Your help, as well as that of the company and broker, which allows us access will be acknowledged in any publications.

I can best be contacted at: Gary L. Kinsland, glkinsland@louisiana.edu.