The New Source to Sink: Opportunities for Geoscientists in Sand and Gravel Mining

Abstract

MOTIVATION Sand and gravel mining, transport, and consumption in the global construction industry is arguably the world’s largest “source-to-sink” (S2S) sediment dispersal system. Construction aggregates are the world’s most extracted solid material resource (OECD, 2019) with 30–50 billion tons currently mined annually, largely used in concrete (UNEP, 2019). Total global sediment flux to oceans is around 19 billion tons annually, of which ~1.5 billion tons is bedload material (Syvitski et al., 2005). While crushed rock is increasingly important in construction aggregates (Torres et al., 2021), natural sand and gravel deposits are still the primary mining targets globally (Torres et al., 2021; UNEP, 2019). Given the fact that construction aggregates are generally coarser than fine sand, the most direct comparison between these two global S2S systems is bedload estimates versus construction aggregates. This makes the global construction S2S system an order of magnitude larger than all the world’s natural coarse-grained S2S systems combined. Because coarse sediment is something that many geoscientists think about daily, this fact presents new opportunities for societally relevant research directions.