Alternative Uses for Seismic Data:  Finding Atlantis
By
Abby Parish, Applied Science Group, NCS SubSea

It seems that every time I am working on a mapping project, a co-worker always pops his head in and asks if I have found Atlantis or Bigfoot yet. Unfortunately, I have to tell him no every time. However, it seems some researchers at Birmingham University have found something very interesting in the North Sea. Using seismic data from oil companies, they have been able to partially map Doggerland, an ancient area that disappeared due to sea level rise (Preston 2015).

People have been finding artifacts, such as 14,000 year old spear points, in the North Sea for years (Preston 2015). It was believed that the area was once a land bridge connecting Britain to the European mainland. Sir Clement Reid was one of the first people to bring the area to public attention when he published a book on the submerged forests of the United Kingdoms in 1913. The Institute of Archaeology and Antiquity at University of Birmingham, along with industry professionals, used several methods including cores and seismic data from oil companies for their research. They were looking to not only get a better understanding of what Doggerland might have looked like in the past (Figure 1), but also to gain some understanding of how climate change and sea level rise could impact the world in the future (Gaffney 2007).


Figure 1. Early Holocene Doggerland (Gaffney 2007) compared to modern day Europe.

When most people think of looking at seismic data, they picture looking deep underground to find oil and gas. When searching for Doggerland researchers mainly studied at a depth between 95 and 165 feet (Preston 2015). In comparison the average well drilled in 2008 was closer to 6,000 feet deep (“Average Depth” 2015). By looking at these shallower depths, the researchers are able to get a picture of what the Doggerland landscape might have looked like thousands of years ago. So far they have found over 690km of coastline, 10 major estuaries, extensive salt-marshes, over 1600km of fluvial systems, and 24 lakes or wetlands (Gaffney 2007).

Focusing on the shallower sections of the seismic data is an area that UHR3D data, acquired using the P-CableTM system, can excel. The SAFE-EBAND Project data volume has a natural bin size of 3.125 x 6.25m, and a vertical resolution of 4 meters or better in the upper 0.500s of data (Brookshire et al. 2015). Just as the researchers at Birmingham University used the existing seismic data to find paleo rivers and lakes, P-CableTM data has been used to locate paleo channels and many other relic of past seafloor geomorphology (Figure 2). These channels are located at the bottom of a mass transport complex. While these might not have ever been rivers, they were most likely areas of channelized flow.


Figure 2. Bottom of a Mass Transport Complex, flattened 58-80 Hz sub-band (Brookshire 2015). Channels approximately 35m wide are visible.

While I have never personally found an ancient civilization at the bottom of the ocean, the P-CableTM technology has the potential to be used for research similar to what they are doing at Birmingham University. Maybe one day the technology can be used for more than exploration and geohazard identification. After all, Atlantis is still out there somewhere.


References
Average Depth of Crude Oil and Natural Gas Wells. (2015, July 31). Retrieved from https://www.eia.gov/dnav/ng/ng_enr_welldep_s1_a.htm
Brookshire Jr, B. N., F. P. Landers, and J. A. Stein. 2015, Applicability of ultra-high-resolution 3D seismic data for geohazard identification at mid-slope depths in the Gulf of Mexico: Initial results. Underwater Technology, 32, no. 4,271-278.
Brookshire, Jr. BN. (2015). Mass transport complex imaging with P-Cable ultrahigh-resolution 3-dimensional seismic. 2015 SEG Near Surface Asia Pacific Conference. Waikoloa, Hawaii. Extended abstract and oral presentation.
Gaffney, V. L., Thomson, K., & Fitch, S. (2007). Mapping Doggerland: The Mesolithic Landscapes of the Southern North Sea. Retrieved from https://books.google.com/books?id=SrsrE8oZx44C&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
Preston, E. (2015, November 27). Hunting for DNA in Doggerland, an Ancient Land Beneath the North Sea. Retrieved from http://www.wired.com/2015/11/hunting-for-dna-in-doggerland-an-ancient-land-beneath-the-north-sea/