Searching for ‘The Second Chamber’ at Newgrange (UNESCO) using geophysics

After 11 years, a team of Slovak researchers once again took part in a geophysical measurement at an almost 5 000-year-old mound in the Boyne Valley in Ireland. The research team at the famous Newgrange included Pavol Zahorec and Ema Nogová from the Earth Science Institute (Slovak Academy of Sciences), Roman Pašteka from the Faculty of Natural Sciences (Comenius University) and Juraj Papčo from the Faculty of Civil Engineering (Slovak University of Technology), who during several days carried out mainly gravimetric and GPR measurements.

Newgrange is known for the existence of an underground chamber with an access passage in one part of it. The remaining part of the mound is unexplored and attracts archaeologist’s attention. A pilot microgravimetric survey in 2011 was focused on validating the methodology for locating the underground spaces above the known chamber. The successful results led to the further cooperation of Slovak and Irish scientists, as well as for the popularisation of geophysical survey in archaeology. The site of Newgrange is not only well known to the professional public, but also popular with the general public in Ireland. The secrets of the mound are subject of a documentary movie by IWR Media Ltd, which we took part in filming. The documentary focuses on research of possible presence of a second chamber in the barrow (‘The Second Chamber’).

Despite the unfavourable measurement conditions (strong winds and unstable ground), we have been better prepared for the environment after our previous measurement experience in 2011, and we achieved a relatively high accuracy of the measurements. In addition to microgravimetry, other methods were used in the survey: GPR (ground penetrating radar), terrestrial laser scanning. The results of the measurements need to be processed and will be available to the public in accordance with the agreed terms and conditions. The research was carried out at the invitation of the Irish company IWR Media Ltd. in cooperation with Landscape & Geophysical Services, and assisted by the Slovak scientific agency VEGA.

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The most modern field gravimeters Scintrex CG-5 and CG-6 were used for the measurement. Difficult measurement conditions required wind shielding and special tripods to stabilize the instruments.
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Measurement by different types of georadar in the area in front of the mound…
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…and on its steep slopes.
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The measurement process was captured in detail for an upcoming documentary film.
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At the last gravimetric point. On the right, Kevin Barton from Landscape & Geophysical Services, Ireland.
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A joint photo of the Slovak research team, with the Newgrange mound in the background