Volcanism and human prehistory in Arabia

Abstract

The Cenozoic harrats (lavafields) of western Arabia constitute one of the major volcanic areas of the world. Recent precise chronometric dating of volcanic rocks in Harrat Rahat makes it possible to outline a detailed chronology of volcanic activity. Likewise, recent advances in archaeology have demonstrated that early humans repeatedly occupied the Arabian Peninsula in the Pleistocene. Most archaeological sites in Arabia correlate with phases of increased rainfall, such as interglacials. However, we should be cautious about reducing the pre- history of Arabia to simply the story of rainfall fluctuation. This paper explores the impacts of volcanism on human populations in Arabia, as a case study of causality and scale in human-environment interactions. Periodic environmental ‘windows of opportunity’ allowed early human groups to expand into western Arabia. However, the western highlands are also home to volcanically active areas that saw repeated eruptions. In the Holocene a major eruption occurred in western Arabia around every 300 years, and the emerging evidence for Pleistocene volcanism demonstrates repeated major eruptions at the same times as early humans were occupying the area. As well as offering a review of human-volcanism interactions in Arabian prehistory, a model is proposed in which volcanic activity in western Arabia may have facilitated further population dispersal. As well as negative health impacts as a ‘push factor’, a balanced perspective on the impacts of volcanism, and associated phenomena such as earthquakes, emphasises possibly positive impacts in terms of factors such as water availability and the formation of fertile volcanic soils. These positive impacts may have offered ‘pull factors’, and facilitated regional occupation longer than would be predicted based on climatic variables alone. This framework offers not only an explanation for some of the characteristics of the Arabian archaeological record, but potentially offers part of the explanation for how early human populations were able to pass through the Saharo-Arabian arid belt from our African birthplace to populate the rest of the world.