Shifting westerlies and precipitation patterns during the Late Pleistocene in southern Africa determined using glacier reconstruction and mass balance modelling

Mills, Stephanie; Grab, Stefan; Rea, Brice R.; Carr, Simon; Farrow, Aidan

doi:10.1016/j.quascirev.2012.08.012

Cited by 69 publications

(52 citation statements)

References 81 publications

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“…However, there exists little synthesis of the research (albeit sparse) undertaken in Lesotho. Not only does the neglect of this country form a notable research gap, but as the highest altitude region in southern Africa, eastern Lesotho reflects a unique environment which has been significantly influenced by snow and ice throughout the late Quaternary 18 . Western Lesotho, by contrast, is situated at low elevation, consisting of lowlands and foothills.…”

Section: Lesotho: a Key Site For Palaeoenvironmental Researchmentioning

confidence: 99%

“…19 The contrast in elevation, topography, and resultant ecosystems across the country presents a valuable context for examining environmental lapse rates and topographic influences on the environment. Furthermore, synoptically this region is important as much of the moisture derives from the Indian Ocean, yet winter snow is a function of the passage of mid-latitude cyclones originating from the southwest of southern Africa 18 . A critical review of the existing palaeoenvironmental literature for this region is thus of importance in directing future research to more accurately address key research uncertainties.…”

Section: Lesotho: a Key Site For Palaeoenvironmental Researchmentioning

confidence: 99%

“…Such glaciation is dated to ~19 500-17 350 calibrated years before present (cal yr BP) 6,12,13 , which coincides with the terminal stage of the LGM in southern Africa 2 . While the accuracy of the term 'niche glaciation' has been queried 29 , evidence based on these moraines for small-scale, spatially restricted glaciation during the LGM is undisputed to date 18 .…”

Section: The Palaeogeomorphological Recordmentioning

confidence: 99%

“…The palaeo-periglacial phenomena indicate colder conditions than at present, with the size of landforms and their likely genesis providing some indication of relative temperature departures 11,15,18 . However, palaeoenvironmental interpretations of associated precipitation levels during these cold periods are conflicting.…”

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confidence: 95%

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multi-disciplinary review of late Quaternary palaeoclimates and environments for Lesotho

Fitchett¹,

Grab²,

Bamford³

et al. 2016

S. Afr. J. Sci.

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Lesotho provides a unique context for palaeoclimatic research. The small country is entirely landlocked by South Africa, yet has considerable variation in topography, climate, and associated vegetation over an approximate east-west transect. The region has been of archaeological interest for over a century, and hosts many Early to Late Stone Age sites with occupation preceding 80 000 years before present. The eastern Lesotho highlands are of interest to periglacial and glacial geomorphologists because of their well-preserved relict landforms and contentious evidence for permafrost and niche glaciation during the late Quaternary. However, continuous proxy records for palaeoenvironmental reconstructions for Lesotho are scarce and hampered by a range of methodological shortfalls. These challenges include uncertain ages, poor sampling resolution, and proxies extracted from archaeological excavations for which there may be bias in selection. Inferences on palaeoclimates are thus based predominantly on archaeological and palaeogeomorphological evidence for discrete periods during the late Quaternary. This review paper presents a more detailed multidisciplinary synthesis of late Quaternary conditions in Lesotho. We simultaneously considered the varying data that contribute to the under-studied palaeoenvironmental record for southern Africa. The collective palaeoenvironmental data for eastern Lesotho were shown to be relatively contradictory, with considerable variations in contemporaneous palaeoclimatic conditions within the study area. We argue that although methodological challenges may contribute to this variation, the marked changes in topography result in contrasting late Quaternary palaeoenvironments. Such environments are characterised by similar contrasting microclimates and niche ecologies as are witnessed in the contemporary landscape. These spatial variations within a relatively small landlocked country are of importance in understanding broader southern African palaeoenvironmental change.

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Section: Lesotho: a Key Site For Palaeoenvironmental Researchmentioning

confidence: 99%

Section: Lesotho: a Key Site For Palaeoenvironmental Researchmentioning

confidence: 99%

Section: The Palaeogeomorphological Recordmentioning

confidence: 99%

mentioning

confidence: 95%

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multi-disciplinary review of late Quaternary palaeoclimates and environments for Lesotho

Fitchett¹,

Grab²,

Bamford³

et al. 2016

S. Afr. J. Sci.

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“…Conociendo la temperatura media de cualquier otro método paleoclimático podemos identificar las condiciones ambientales exactas de un lugar mientras el glaciar estaba presente. Si tenemos una base de datos con diferentes localizaciones, condiciones ambientales y dataciones, podemos reconstruir el clima de regiones enteras para eventos climáticos concretos (Mills et al, 2012). Además los datos de cambio en la ELA pueden añadirse a modelos climáticos ya desarrollados, como el de Renssen et al (2001), mejorando su calibración (Figura 9).…”

Section: Puede Decir El Pasado Sobre El Futuro?unclassified

Geomorfología en Geografia y Ordenación del territorio, una perspectiva multiescalar y diacrónica

Pellitero¹

2015

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RESUmEN: Se presentan ejemplos de estudios geomorfológicos a distintas escalas, tanto relativos a procesos actuales como formas y depósitos resultados de procesos geomorfológicos pasados. A escala local se muestran los ejemplos de la gestión de deslizamientos y desprendimientos en la Calzada del Gigante (Irlanda del Norte) y el estudio de flujos de derrubios de Blatten (Suiza), así como las aplicaciones de la geodiversidad a escalas de detalle. A escala regional los ejemplos se centran en la protección y promoción del relieve por su valor patrimonial en Castilla y León y Suiza, explicado como entroncan con los procesos de ordenación territorial. A escala global se explica como la geomorfología subglaciar es esencial en la explicación del proceso de fusión acelerado de la Antártida Occidental, con implicaciones para el aumento del nivel del mar en todo el mundo. Por último se exponen los estudios de ambientes y procesos cuaternarios en Europa, tanto climáticos (el Dryas Reciente como evento climático que puede repetirse en el contexto actual) como dinámicos (la colonización del territorio desde el Neolítico y la intensificación de procesos erosivos). Con este trabajo se pretende destacar la importancia de la Geomorfología en la gestión territorial tanto para la protección del medio natural como la preparación ante riesgos naturales e impactos potenciales de la actividad antrópica. PALAbRAs CLAVE: Geomorfología, Ordenación del Territorio, escala, Geografía GEOmORPhOLOGY IN GEOGRAPhY AND REGIONAL PLANNING, A mULTISCALE PERSPECTIvE AND DIAChRONIC ABSTRACT: Some examples of geomorphological studies on different scales are presented, whether they are related to current geomorphic processes or to landforms and deposits inherited from former processes. On a local scale the examples shown are the rockfall and landslide management at the Giant's Causeway (Northern Ireland) and the research on debris flows that threaten the village of Blatten (Switzerland), as well as the application of geodiversity assessment on detail scales. On a regional scale examples are focused on the protection of relief as a heritage value in Castilla y León and Switzerland, explaining how they match within land management processes. O a global scale it is explained how subglacial morphology is essential to explain the ablation and potential collapse of Western Antarctica glaciers, whose melt would affect the world's sea level. Finally examples are shown of Quaternary environments and processes reconstruction in Europe,

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A multi‐proxy analysis of late Quaternary palaeoenvironments, Sekhokong Range, eastern Lesotho

Fitchett

Grab

Bamford

et al. 2016

J Quaternary Science

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The eastern Lesotho Highlands host an array of periglacial and glacial geomorphic features. Their analysis has provided past climate interpretations predominantly for cold periods, yet no multi‐proxy temporally continuous palaeoenvironmental records exist. This study presents a palaeoenvironmental reconstruction based on sedimentary characteristics, fossil pollen and diatoms from an alpine wetland located in the Sekhokong Mountain Range. The record commences in the late Pleistocene with a wet period from ∼16 450 to 14 440 cal a BP, interrupted by dry conditions from ∼16 350 to 15 870 cal a BP. From ∼14 150 to 8560 cal a BP, drier conditions are inferred, slowly transitioning to warmer, wetter conditions. Warmer, dry conditions are inferred for ∼8560–7430 cal a BP, followed by cold, wet conditions from ∼7280 to 6560 cal a BP. A dry, warmer period occurs from ∼6560 to 3640 cal a BP indicated by pollen, diatom and sedimentary records, followed by cool, wet conditions from ∼3400 to 1200 cal a BP. The period from ∼1110 cal a BP to the present is characterized by progressive drying. Pronounced cold events are detected from the diatom record. Moisture records appear relatively specific to the topographic setting of Sekhokong near the Great Escarpment edge, probably driven by orographically constrained synoptic controls.

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Shifting westerlies and precipitation patterns during the Late Pleistocene in southern Africa determined using glacier reconstruction and mass balance modelling

Cited by 69 publications

References 81 publications

multi-disciplinary review of late Quaternary palaeoclimates and environments for Lesotho

multi-disciplinary review of late Quaternary palaeoclimates and environments for Lesotho

Geomorfología en Geografia y Ordenación del territorio, una perspectiva multiescalar y diacrónica

A multi‐proxy analysis of late Quaternary palaeoenvironments, Sekhokong Range, eastern Lesotho

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