The Last Permafrost Maximum (LPM) map of the Northern Hemisphere: permafrost extent and mean annual air temperatures, 25–17 ka BP

Abstract

This paper accompanies a map that shows the extent of permafrost in the Northern Hemisphere between 25 and 17 thousand years ago. The map is based upon existing archival data, common throughout the Northern Hemisphere, that include ice-wedge pseudomorphs, sand wedges and large cryoturbations. Where possible, a distinction is made between areas with continuous permafrost and areas where permafrost is either spatially discontinuous or sporadic. The associated mean annual palaeo-temperatures that are inferred on the basis of present-day analogues increase understanding of the possible changes in permafrost extent that might accompany current global warming trends. Areas with relict permafrost and areas that were formerly exposed due to lower sea level (submarine permafrost) are also mapped. Mapping is mostly limited to lowland regions (areas approximately <1000 m a.s.l.). Striking features that appear from the map are (i) the narrow permafrost zone in North America, which contrasts with the broader LPM permafrost zone in Eurasia (that may be related to different snow thickness or vegetation cover), (ii) the zonal extent of former LPM permafrost (that may reflect sea-ice distribution), which contrasts with the present-day pattern of permafrost extent (especially in Eurasia) and (iii) the relatively narrow zones of LPM discontinuous permafrost (that may indicate strong temperature gradients).

Coupled Northern Hemisphere permafrost–ice-sheet evolution over the last glacial cycle

“…However, the estimates of Vandenberghe et al (2012) include also discontinuous permafrost. The modeled permafrost extent is in even better agreement with the continuous permafrost extent estimates in Vandenberghe et al (2014). Over North America, permafrost is simulated south of the LIS mainly over the Rocky Mountains, in very close agreement with reconstructions (Vanden- berghe et al, 2014) and PMIP3 ensemble model estimates for the LGM (Saito et al, 2013).…”

Weichselian permafrost depth in the Netherlands: a comprehensive uncertainty and sensitivity analysis

“…These values are based on periglacial deformation phenomena (e.g. ice-wedge casts and large-scale involutions) in the shallow subsoil and their present-day distribution in areas of stable continuous permafrost (Vandenberghe and Pissart, 1993;Huijzer and Vandenberghe, 1998;Vandenberghe et al, 2014). The following MIS3 is characterized by a somewhat milder climate, showing less periglacial deformation of the subsoil.…”

“…Himalaya, northern Rocky Mountains; Vandenberghe et al, 2014). Today, the lowlands of northwestern Europe are free of permafrost.…”

“…Today, the lowlands of northwestern Europe are free of permafrost. However, palaeoclimatic reconstructions have pointed out that much of northwestern Europe experienced permafrost conditions during the last glacial maximum (LGM; Huijzer and Vandenberghe, 1998), recently also termed the last permafrost maximum (LPM; Vandenberghe et al, 2014). Notwithstanding the fact that recent studies suggest global warming to continue or accelerate during the next 100 years (Stocker et al, 2013), or that we might be facing an exceptionally long interglacial (Berger and Loutre, 2002), it is expected that periglacial conditions will reappear in northwestern Europe (e.g.…”

Advancement toward coupling of the VAMPER permafrost model within the Earth system model &lt;I&gt;i&lt;/I&gt;LOVECLIM (version 1.0): description and validation

“…9), which is an area documented for having relict permafrost (Zemtsov and Shamakhov, 1993;Ananjeva et al, 2003). It is also identified in the "Circumarctic Map of Permafrost and GroundIce Conditions" (Brown et al, 2014) and "The Last Permafrost Maximum (LPM) map of the Northern Hemisphere" (Vandenberghe et al, 2014). But it should be noted that not all the relict permafrost in western Siberia is of late Pleistocene origin and may be from earlier cold stages (Zemtsov and Shamakhov, 1993;French, 2007).…”