Jorge Adrián Strelin

Instituto Antártico Argentino and CICTERRA UNC · Earth Science

Los glaciares de roca se cuentan entre las geoformas criogénicas más notables de la isla James Ross. La génesis de los mismos se atribuye a la convergencia de una serie de condiciones ambientales de origen morfoestructural y morfogenético. Entre las morfoestructurales se destaca la existencia de mesadas basálticas que proveen la materia prima para...

When calculated with the commonly accepted average Northern Hemisphere production rate, 10 Be dates of surface boulders on moraines in the Lago Argentino area of Patagonia are younger than minimum-limiting 14 C ages for the same landforms. This disagreement could result from the lack of a regional 10 Be production-rate calibration site. To assess t...

To provide insights into glacier-climate dynamics of the South Shetland Islands (SSI), NW Antarctic Peninsula, we present a new deglaciation and readvance model for the Bellingshausen Ice Cap (BIC) on Fildes Peninsula and for King George Island/Isla 25 de Mayo (KGI) ~62°S. Deglaciation on KGI began after c. 15 cal. ka BP and had progressed to withi...

The timing and impact of deglaciation and Holocene readvances on many ice-free terrestrial continental margins of the Antarctic Peninsula have been long-studied but remain debated. Potter Peninsula on King George Island (Isla 25 de Mayo), South Shetland Islands (SSI), NW Antarctic Peninsula has a detailed assemblage of glacial landforms, geomorphol...

The timing of mid–late Holocene deglaciation and glacier readvances on the South Shetland Islands, northern Antarctic Peninsula has been long debated. We used a combined geomorphological, chronological, and palaeolimnological approach to develop a new readvance model for the Bellingshausen Ice Cap (BIC) on the Fildes Peninsula, King George Island/I...

We present the description and interpretation of a James Ross Island Volcanic Group (JRIVG) succession around the Cerro Domo and Ventisqueros Mesa area. Our aim is to reconstruct the volcanic evolution and provide new palaeoenvironmental information for the northwest sector of James Ross Island, northern Antarctic Peninsula. We present representati...

James Ross Island, Antarctic Peninsula, has recently experienced severe climate change: warming from the 1970s until the early 2000s and cooling from the early 2000s until around 2014. Lachman II, a 2-km long debris-covered glacier (ice-cored rock glacier), is located at the northern part of James Ross Island. On Lachman II, the surface elevation l...

We obtained 49 new 10 Be ages that document the activity of the former Northern Antarctic Peninsula Ice Sheet, and subsequently the James Ross Island Ice Cap and nearby glaciers, from the end of the last glacial period until the last ∼100 years. The data indicate that from >11 to ∼8 ka marked recession of glacier systems occurred around James Ross...

Monitoring of active layer thawing depth and active layer thickness (ALT), using mechanical pronging and continuous temperature data logging, has been undertaken under the Circumpolar Active Layer Monitoring – South (CALM-S) program at a range of sites across Antarctica. The objective of this study was to summarize key data from sites in different...

The behavior of subtropical glaciers during Middle to Late Pleistocene global glacial maxima and abrupt climate change events, specifically in Earth's most arid low-latitude regions, remains an outstanding problem in paleoclimatology. The present-day climate of Cordillera Oriental, in arid northwestern Argentina, is influenced by shifts in subtropi...

Recent studies have revealed that in high-altitude mountain environments the global warming trend over the last few decades tends to be strongly amplified. However, few attempts have been made to monitor the possible effects of such climate changes on high-altitude rock glaciers. In this paper, we provide a geomorphic analysis of the Varas rock gla...

We present a comprehensive 10Be chronology for Holocene moraines in the Lago Argentino basin, on the east side of the South Patagonian Icefield. We focus on three different areas, where prior studies show ample glacier moraine records exist because they were formed by outlet glaciers sensitive to climate change. The 10Be dated records are from the...

La Cordillera Oriental de Argentina (COA) presenta una forma elongada norte-sur extendiéndose desde los 22º hasta los 26,3º LS. Actualmente debido a un efecto orográfico en las precipitaciones presenta una notable asimetría entre su vertiente oriental más húmeda y la occidental más seca. Durante el Pleistoceno tardío numerosos glaciares ocuparon lo...

The first Holocene marine transgression reached the inner fiords of King George Island approximately at 9,5ka BP according to Sugden and John (1973). This age marks today the minimum age of the end of the last glacial period obtained on land and the start of the Holocene in this Antarctic sector. Following the first Holocene marine transgression, W...

In contrast to off-and near-shore geomorphological and stratigraphical studies on former glacier dynamics on the Antarctic Peninsula, such studies on ice-free areas on-land are scarce. In order to contribute to the reconstruction of past glacial configurations and the deglaciation history of this region, further investigations should be conducted o...

The late-glacial sedimentologic and geomorphic record of the former Patagonian ice sheet remains mostly unstudied despite the fact that it affords invaluable evidence for glaciologic processes during the last glacial-interglacial transition (i.e., 18-11.5 ka). This information is critical if landforms (e.g., moraines) and associated sediments are t...

Although the depositational environment assigned by Darwin to the large erratic blocks and gravels in the Río Santa Cruz valley has been reinterpreted, his geomorphological and stratigraphic observations are still in force. The large erratic blocks he described as crowning the Condor Cliff terrace and spread at the bottom of the valley just east of...

We present new geomorphic, stratigraphic, and chronologic data for Holocene glacier fluctuations in the Lago Argentino basin on the eastern side of the southern Patagonian Andes. Chronologic control is based on 14C and surface-exposure 10Be dating. After the Lateglacial maximum at 13,000 cal yrs BP, the large ice lobes that filled the eastern reach...

King George Island (Isla 25 de Mayo) is the largest one of the South Shetland Islands (SShI). This archipelago is located approximately 120 km NW of the Antarctic Peninsula, from which it is separated by the Bransfield Strait (Mar de la Flota). The SShI are located just south of the Antarctic Convergence Zone in a key location for investigating gla...

James Ross Island Volcanic Group (JRIVG) is one of the largest (>4500 km 2) neogene mafic volcanic provinces in the Antarctic Peninsula region (Nelson 1966). The main lithologies are alkalic olivine basalts, with minor basanites, picrites, and segregations of tephri-phonolite compositions, which together show strong geochemical similarities with OI...

Since Sugden and John's (1973) paper regarding the glacier fluctuations in the South Shetland Islands, it is generally accepted that the first Holocene marine transgression of this archipelago occurred at least by 9540 ± 235 cal yrs BP (del Valle et al. 2007, Hall 2010). All radiocarbon ages presented here are calibrated with Calib611 software (Stu...

We present new geomorphic, stratigraphic, and chronologic data for Holocene glacier fluctuations in the Lago Argentino basin on the eastern side of the southern Patagonian Andes. Chronologic control is based on 14C and surface-exposure 10Be dating. After the Lateglacial maximumat 13,000 cal yrs BP, the large ice lobes that filled the eastern reache...

En este trabajo se presenta un inventario y caracterización morfológica de los glaciares de roca en la Cordillera Oriental argentina (22-25º S) y se discute el signifi cado climático y los factores que controlan su distribución. También se presenta el caso particular del glaciar de roca activo Varas, ubicado en el extremo sur de la sierra de Zenta,...

This paper presents an inventory and a morphologic characterization of the rock glaciers in the arid region of the Argentinean Cordillera Oriental (22-25 degrees S), and discusses the climatic significance and the factors controlling their distribution. We also present a detailed characterization of the Varas rock glacier, which is located in the s...

We use 10Be and 14C dating of glacier deposits in Patagonia and in the Southern Hemisphere middle latitudes to reconstruct millennial scale paleoclimate during the Late Glacial Antarctic Cold Reversal (14,500 - 12,900 cal. yrs BP) and European Younger Dryas stadial (12,900 - 11,700 cal. yrs BP) time periods. First, however, we locally calibrate the...

The Cachorro valley is located on the eastern shore of the South branch of Lago Argentino (Patagonia, Argentina) and is interpreted as a glacial trough originated by the uphill override of the glacier that occupied the South branch of the lake during the last glaciation. Four moraine closures were detected in the valley, characterized and later on...

El Grupo Volcánico James Ross Island (GVJRI; Adie 1953) conforma un extenso campo volcánico predominantemente máfico alcalino que supera los 4500 km 2 de superficie, cuya máxima actividad tuvo lugar entre el Mioceno tardío y el Pleistoceno medio (Smellie et al., 2008 y referencias allí citadas). El ambiente eruptivo del GVJRI ha sido estudiado por...

Improvements in 10Be techniques now allow precise exposure dating on a subcentury timescale over the last 1000 years, and reconstruction of glacial records that overlap with and extend well beyond the short historical record. In settings where inheritance and postdepositional processes are minimal and moraines are well-preserved, 10Be age accuracy...

Althoughthe depositational environment assigned by Darwin to the large erratic blocksand gravels in the Río Santa Cruz valley has been reinterpreted, hisgeomorphological and stratigraphic observations are still in force. The largeerratic blocks he described as crowning the Condor Cliff terrace and spread atthe bottom of the valley just east of this...

Resumen La mayoría de los glaciares orientales de Tierra del Fuego muestran notables cambios desde la década de los setenta, que indican un significativo proceso recesivo general en el área. El glaciar Vinciguerra, que en 1970 presentaba una extensión de 1,16 km 2 , perdió el 44% de su superficie, retrocediendo 460 m y dando lugar a la formación de...

We describe field measurements (ground-penetrating radar (GPR), geodetic survey and ice-core drilling) to provide new information on the movement mechanism and internal structure of a polar rock glacier on James Ross Island, Antarctic Peninsula. We collected GPR data along longitudinal and transverse profiles. The longitudinal GPR profiles identify...

Investigations carried out in the Ema Glacier valley, Tierra del Fuego, on the eastern side of Monte Sarmiento Massif, enable the recognition of five Holocene glacial events. The oldest glacial advance deposited the so-called external moraines of Ema Glacier, with a probable occurrence between 6000 and 5000 14 C y BP without discarding the potentia...

Past and present glacier changes have been studied at Cordón Martial, Cordillera Fueguina Oriental, Tierra del Fuego, providing novel data for the Holocene deglaciation history of southern South America and extrapolating as well its future behavior based on predicted climatic changes. Regional geomorphologic and stratigraphic correlations indicate...

Large−scale stone−banked lobes and terraces are distributed over an area of 1 km 2 of gentle slope on Rink Plateau in the northern part of James Ross Island, Antarctic Penin− sula region. Topographically, there are two main features: relatively high risers up to 5 m high and distinct frontal ridges. In order to understand the processes responsible...

This study used ground penetrating radar soundings to examine a tongue−shaped rock glacier (6404’S 5825’W) on James Ross Island, Antarctic Peninsula, in January 2005. The rock glacier studied has multiple well−developed transverse ridges and approximately 800 m long from the talus of its head to its frontal slopes and is 300 m wide in the middle. T...

A glacier lake outburst flood occurred on James Ross Island, Antarctic Peninsula region, during the 2004–2005 austral summer season. The source lake was located on the Lachman II ice−cored rock glacier, and formed prior to 1980. The size of the lake has been increasing gradually since the 1990s. The lake basin extended to approximately,220 m in len...

Rock glaciers are considered amongst the most conspicuous landforms of James Ross Island. Their formation follows the convergence of a series of morphostructural and morphogenetic environmental conditions. The most important morphostructural condition is the presence of basaltic mesas that provide the raw material for the debris cover of the rock g...

A survey of some relict and active landforms in the Lachman and Rink Crags areas of NW James Ross Island on the Antarctic Peninsula has yielded new evidence that provides a better understanding of the Holocene morphoclimatic evolution of this currently deglaciated sector of James Ross Island. Six Holocene (mainly land-grounded) glacial advances wer...

Rink Crags Plateau is located on the northwestern part of James Ross Island, northeast of Antarctic Peninsula. Stone-banked lobes and terraces of various sizes are developed in a 1 km2 area of average 4° slope upon the plateau. The largest lobes rise up to 5 m above the surrounding surface. Monitoring of painted markers upon the stone-banked lobes...

We analysed vegetation patterns in relation to geomorphology in subantarctic Andean tundra (Tierra del Fuego, southern Argentina). Habitat variation associated with geomorphology played a major role in structuring vegetation. On coarse-grained debris of talus cones, the vegetation is dominated by the epilithic fruticose lichen Neuropogon aurantiaco...

Copyrighted by American Geophysical Union. Bransfield Strait is a Quaternary, ensialic back arc basin at the transition from rifting to spreading. Fresh volcanic rocks occur on numerous submarine features distributed along the rift axis, including a discontinuous neovolcanic ridge similar to the nascent spreading centers seen in some other back arc...

RESUMEN Durante los últimos 100 años el glaciar O'Higgins, afluente del lago O´Higgins-San Martín, experimentó un marcado retroceso de su frente y una notable disminución en su espesor. Las laderas del valle, de fuerte pendiente y cubiertas con depósitos morrénicos se encuentran marcadamente desestabilizadas, favoreciendo procesos de degradación ta...

In the west-central part of Lago Argentino, the Puerto Bandera moraines are clearly detached from longer, more prominent moraines of the last glaciation and from shorter and smaller Neoglacial moraines. Scientists have long speculated about the age of the Puerto Bandera moraines. Detailed geomorphologic studies in the western area of Lago Argentino...

Remnants of an old aggradational landscape, Cerro Cuadrado Proglacial, are preserved on top of the high mesetas Pampa Alta and La Meseta on both sides of the upper Santa Cruz river valley, South Patagonia.A first dissection of the mesetas, attributable to extended river erosion, predates the expansion of glacier lobes down the piedmontane area. The...

Lack of glacier cover in north-western James Ross Island, favours the development of different periglacial landforms. Ice-cored rock glaciers, protalus lobes, and the recent discovery of protalus ramparts are some of the most conspicuous cryogenic features. The ice-cored rock glaciers appear in a complex and genetically related landform system. Bes...

Stratigraphic and petrographic studies of Cenozoic volcanic and volcaniclastic rocks of Rink Crags, western James Ross Island, allow for the identification of five eruptive units separated by uncorformities of different magnitude. Eruptive unit 1 conforms a subaqueous tuff cone composed of hydroclastic tuff and lapilli (explosive phase), interbeded...

Pleistocene Glaciations from Lago Argentino and Río Santa Cruz Upper Valley. Five Pleistocene glaciations are recognized in the Río Santa Cruz area. The oldest, Estancia La Fructosa Glaciation, is the most expanded to the East (70° 27' W) and comprises three pulses or stadials, being the third the most conspicuous. During the Chuñi Aike Glaciation...

The recent discovery of moraine deposits in the vicinity of the Río Santa Cruz and Río Coyle valleys and the analysis of related geological and geomorphological features have resulted in a new interpretation of the expansions of the oldest extra-andean glaciers. The paleolandscape preserved on top of the Meseta Pampa Alta records the oldest moraine...

Bransfield Strait is a marginal basin landward of the South Shetland Trench. It lies between the South Shetland Islands and the tip of the Antarctic Peninsula and is an example of an extensional basin formed by rifting within a continental volcanic arc. The Antarctic Peninsula is the product of at least 200 m.y. of subduction with the majority of t...

INTRODUCCIÓN Hasta el presente se consideraba a la isla James Ross como un gran complejo volcánico de edad pliocena a pleistocena donde los depósitos volcánicos y volcaniclásticos, pertenecientes al Grupo Volcánico Isla James Ross (Adie, 1953), generaron formas submarinas del tipo tuyas posteriormente emergidas y fuertemente erodadas por los glacia...

James Ross Island is the largest of the so-called James Ross Islands Group located on the northeastern part of the Antarctic Peninsula. The main geomorphologic features of the island are the results of glacial processes and on this basis James Ross Island is divided into two sectors: one related to the Mount Haddington Ice Cap and the other related...

James Ross Island is the largest of the so-called James Ross Islands Group located on the northeastern part of the Antarctic Peninsula. The main geomorphologic features of the island are the results of glacial processes and on this basis James Ross Island is divided into two sectors: one related to the Mount Haddington Ice Cap and the other related...