The case of a southern European glacier which survived Roman and medieval warm periods but is disappearing under recent warming

Abstract

Abstract. Mountain glaciers have generally experienced an accelerated retreat over the last 3 decades as a rapid response to current global warming. However, the response to previous warm periods in the Holocene is not well-described for glaciers of the southern Europe mountain ranges, such as the Pyrenees. The situation during the Medieval Climate Anomaly (900–1300 CE) is particularly relevant since it is not certain whether the southern European glaciers just experienced significant ice loss or whether they actually disappeared. We present here the first chronological study of a glacier located in the Central Pyrenees (NE Spain), Monte Perdido Glacier (MPG), carried out by different radiochronological techniques and a comparison with geochemical proxies from neighbouring palaeoclimate records. The chronological model evidences that the glacier persisted during the Roman period and the Medieval Climate Anomaly. The apparent absence of ice in the past ∼ 600 years suggests that any ice accumulated during the Little Ice Age has since ablated. This interpretation is supported by measured concentrations of anthropogenic metals, including Zn, Se, Cd, Hg and Pb, which have concentrations well below those typical of industrial-age ice measured at other glaciers in Europe. This study strengthens the general understanding that warming of the past few decades has been exceptional for the past 2 millennia.

Record summer rains in 2019 led to massive loss of surface and cave ice in SE Europe

“…Therefore, whereas the projected increase in air temperature in mountain areas would result in enhanced mass loss for surface glaciers, the same rising temperatures might only marginally affect ice volume changes in caves. Monitoring studies in ice caves has been done sporadically since the mid-20th century (Racovita, 1994;Luetscher et al, 2005;Perşoiu and Pazdur, 2011;Kern and Perşoiu, 2013;Munroe, 2021), the results showing that reduction in winter precipitation and increase in winter temperatures are the main drivers behind loss of ice, with summer temperatures having a negligible role. Additionally, studies of perennial ice deposits in caves in Norway, Romania and Switzerland have suggested that above-average summer precipitation might play an important role in the overall volume changes in cave glaciers (Stoffel et al, 2009;Feurdean et al, 2011;Lauritzen et al, 2018).…”

Cronología “extrema”: Generación de modelos cronológicos robustos a partir de diferentes métodos de datación; ejemplos en la Península Ibérica

“…Están también bien identificadas, geomorfológicamente, las dos morrenas de la Pequeña Edad del Hielo (PEH) (García-Ruiz et al, 2014) pero, sin embargo, se desconoce la respuesta del glaciar a periodos cálidos anteriores como el Periodo Romano (500 BCE-400 años CE) o la Anomalía Climática Medieval (MCA, 900 -1300 años CE). Responder a la pregunta de qué extensión tenía el glaciar en esos periodos, e incluso determinar si había llegado a desaparecer completamente alguna vez, fue el principal objetivo del estudio y tenía que ser resuelto con la datación del hielo presente hoy en el glaciar (Moreno et al, 2021).…”

“…En gris, se muestra un intervalo donde la acumulación de hielo fue especialmente baja, predominando los procesos de fusión. Modificada de Moreno et al, (2021). 2), obtained using the Clam software (Blaauw, 2010;Blaauw et al, 2019).…”

“…An interval interpreted as a period with low ice accumulation is indicated by a gray band. Modified from Moreno et al, (2021).…”

“…En gris, se muestra un intervalo donde la acumulación de hielo fue especialmente baja, predominando los procesos de fusión. Modificada deMoreno et al, (2021).Figure 2. (Left) Simplified scheme with the position of the 100 samples collected along the slope of Monte Perdido glacier (red line I-II marks the studied profile; identification of the samples is MP-0 to MP-100).…”