Kaarel Orviku: How to find a treasure with radar?

Kaarel Orviku, PhD in Geology, Tallinn University, explains how a georadar scanner - that looks like a lawnmower - works. WW II trenches that were hidden underground were revealed during a georadar demonstration in Mustamäe.

Only because of developments in technology since the mid-twentieth century, have researchers had at their disposal a method of probing the upper layers of soil with radio waves – known as geolocation.   From the beginning of the 1970s the method has been widely used in many countries during various geological and geotechnical investigations. It has also been used in preliminary archaeological investigations.

Preliminary investigations of vast areas using georadar enable investigators to receive information on the structure of the upper soil layers and foreign bodies if they are present. At the same time, georadar investigations are environmentally friendly, because the use of radar in nature does not damage the soil or plant growth.

Using the investigation results, it is possible to significantly reduce the amount of expensive and time-consuming geological drilling in the area of archaeological digging, by directing the drilling to the key sites of the study. With clear visibility, the ground can be measured with a georadar up to a depth of 30 meters. 

Since the mid-1990s, Kaarel Orviku has promoted the use of georadar in Estonia for scientific and applied geology, archaeology and other similar investigations. Georadar was used to provide a detailed analysis of the terrain beneath the asphalt cover at Tallinn Airport, the depth of different soil layers, especially the depth of the slate belt in the light cable utility line between Paldiski and Klooga, and Saku and Saue. The likelihood of finding fracture zones of high water content in the Tammsaare Road construction area was also investigated.

All data acquired by a georadar scanner can be constantly monitored during the work process and also stored. Important objects discovered during the scanning process can be investigated more thoroughly by probing the upper layers of soil with lightweight soil drills.  Combining different investigation methods like this has provided us with new and valuable scientific information in recent years, e.g. the development and dynamics of vast dune areas within old coastal formations as well as the development process of small lakes and the texture of lake-bottom sediments. 

Dr. Kaarel Orviku has studied the distinctive characteristics of the construction and development of sea shorelines against the background of global climate changes for more than 60 years.  The summarized research results from the last few years of both Dr. Orviku and his colleagues have been published in several specialised international encyclopaedic collections dealing with beaches of the world and the processes involved with them.

Applied research on the reciprocal effects between the beach environment and human activity has had an important place in his research. Numerous expert opinions have been compiled using these results and developers and decision makers have used this information.  Scientifically justified opinions regarding the nature of beach processes and the way in which beaches develop provided valuable additional information used in the design of several sea ports (Kunda, Sillamäe) and beach fortifications.

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