Aaron Watson Archaeology Research
Easter Aquorthies
Easter Aquorthies is a well preserved example of a recumbent stone circle near Aberdeen. There are many similar sites in north-east Scotland, and it has been recognised that many were placed to view the movement of the moon. The stones of Easter Aquorthies also have an extraordinary variety of colours and textures, including quartz banding that glows in moonlight.
Easter Aquorthies is graded in height, with the tallest stones flanking a large ‘recumbent’ stone. Two stones also project from this stone towards the centre of the ring, creating a distinctive alcove. This arrangement of stones reflects sound across the interior of the circle. In addition, these sounds ricochet between other stones generating complex and subtle echoes.
Working with acoustician Dr David Keating, a method was developed to measure these experiences. A loudspeaker was placed in the alcove created by the recumbent and its flanking blocks. This emitted pink noise at a constant volume, and digital recordings were systematically taken across the circle.
The results were plotted onto a plan of the site. This clearly shows how the recumbent stone generates echoes across the centre of the circle. This was contrasted against recordings taken in an open space where the sound diffuses equally in all directions.
Interpreting the acoustics of Easter Aquorthies
Since the acoustic work at Easter Aquorthies, excavations conducted by Reading University at a number of recumbent stone circles across Aberdeenshire. It seems that these circles were constructed in a series of phases towards the end of the Neolithic (around 2000 BC). The earliest feature at each site was a low circular ring cairn, within which fires and funerary pyres were burnt. The standing stone circle was added later to enclose the ring cairn, which continued to be a focus for the treatment and deposition of the dead.
It is very likely that there was once a ring cairn inside Easter Aquorthies. This suggests that the sound reflections would have been most obvious at the centre of the ring cairn, the focal point of the monument. Indeed, only those people who were inside would have heard the distinctive echoes.
Easter Aquorthies is likely to have been a venue for gatherings of people, quite likely in relation to the cycle of the moon. Perhaps the arrangement of stones around the recumbent acted rather like a stage in a theatre, not only acting as a visual backdrop but reflecting sound during ceremonial performances.