One Comment

  1. I was surprised to see that you just visited the Atacama Desert. I’ve spent the last decade doing research to reconstruct the history of vegetation, ground-water levels, and precipitation in the Atacama over the last 40,000 years. You can download the published papers from my website. By the way, we’ve visited a number of the commercial nitrate deposits that were mined beginning in the 1830’s, with peak production around 1930. Over millions of years, salts produced by photoreactions in the atmosphere (nitrate, idodate, perchlorate, etc.) have accumulated on what is the most stable and arid landscape on Earth, a narrow strip 30 x 700 km long (mostly between 1000 and 2000 m elevation) in the hyperarid core of the Atacma. Since there is hardly any rain, these highly mobile, soluble salts are never leached and just accumulate into these thick caliche deposits. So does it ever rain in the hyperarid core of the Atacama, where no vascular plants occur? When you visit these mines, you can usually see tailings that have been dissected by runoff at least once since the mine was in operation. I’m guessing there’s nowhere in the Atacama where it doesn’t rain for more than a century, and that these dissected tailings represent a precipitation event every few decades. If you’re interested in reading more about the prehistory of climate, vegetation and ground-water levels, take a look at some of my papers (Betancourt 2000, Latorre et al. 2002, 2003, 2005 2006; Maldonado et al. 2005; Rech et al. 2002, 2003; Maier et al. 2004; Drees et al. 2006). I’ve been incredibly lucky to work in such a fascinating and extreme environment. Cheers, Julio Betancourt

Comments are closed.