Factors influencing the ground thermal regime in a mid-latitude glacial cirque (Hoyo Empedrado, Cantabrian Mountains, 2006–2020)

.Air and near-surface ground temperatures were measured using dataloggers over 14 years (2006–2020) in 10 locations at 2262 to 2471 m.a.s.l. in a glacial cirque of the Cantabrian Mountains. These sites exhibit relevant differences in terms of substrate, solar radiation, orientation, and geomorphology. Basal temperature of snow (BTS) measurements and electrical resistivity tomography of the talus slope were also performed. The mean annual near-surface ground temperatures ranged from 5.1 °C on the sunny slope to 0.2 °C in the rock glacier furrow, while the mean annual air temperature was 2.5 °C. Snow cover was inferred from near-surface ground temperature (GST) data, estimating between 130 and 275 days per year and 0.5 to 7.1 m snow thickness. Temperature and BTS data show that the lowest part of the talus slope and the rock glacier furrow are the coldest places in this cirque, coinciding with a more persistent and thickest snow cover. The highest temperatures coincide with less snow cover, fine-grained soils, and higher solar radiation. Snow cover has a primary role in controlling GST, as the delayed appearance in autumn or delayed disappearance in spring have a cooling effect, but no correlation with mean annual near-surface ground temperatures exists. Heavy rain-over-snow events have an important influence on the GST. In the talus slope, air circulation during the snow-covered period produces a cooling effect in the lower part, especially during the summer. Significant inter-annual GST differences were observed that exhibited BTS limitations. A slight positive temperature trend was detected but without statistically significance and less prominent than nearby reference official meteorological stations, so topoclimatic conditions reduced the more global positive temperature trend. Probable existence of permafrost in the rock glacier furrow and the lowest part of the talus slope is claimed; however, future work is necessary to confirm this aspect.S

Rasgos morfométricos y morfodinámicos de los glaciares rocosos relictos de la Sierra de Gistredo (Montaña Cantábrica, León)

566 p.La constatación de glaciares rocosos relictos en el Noroeste de las Montañas Cantábricas se inicia al final de la década de los ochenta del siglo pasado con el trabajo de Alonso(1989) en la zona de Degaña-Leitariegos, existiendo nuevas aportaciones a lo largo de los noventa y principios de sigl

Ejemplos de formas de relieve indicadoras de diferentes paleoclimas en la Cordillera Cantábrica

Las formas de relieve son el resultado de la acción de un conjunto de procesos que actúan bajo determinadas condiciones ambientales, es decir, bajo diferentes tipos de clima que configuran los sistemas morfoclimáticos. A lo largo del tiempo geológico se suceden sobre un mismo espacio diferentes sistemas climáticos cuyo resultado es la superposición de formas de relieve diversas y diferentes, lo que implica la existencia de formas heredadas que enriquecen los paisajes naturales e incrementan la geodiversidad. El estudio de varios ejemplos de herencias morfoclimáticas en la vertiente meridional de la Cordillera Cantábrica (formas de relieve kársticas, fluviales, glaciares, periglaciares) demuestra la sucesión de procesos y formas de relieve a escala del tiempo geológico en un espacio relativamente pequeño. Los ejemplos estudiados implican que el cambio climático es algo intrínsecamente unido a la sucesión de procesos geomorfológicos cuando la escala de análisis es el largo plazo, de miles o cientos de miles de año

Distribución y caracterización de bloques aradores en el noroeste de la península ibérica: el Alto Sil y el macizo de Vizcodillo

Los bloques aradores son una de las formas periglaciares más características de las montañas ibéricas, pero los estudios específicos sobre los mismos son muy escasos. En este trabajo se presentan datos de medio centenar de bloques de dos enclaves del noroeste ibérico: el Alto Sil (Cordillera Cantábrica) y el macizo de Vizcodillo (Sierra de la Cabrera). En ambos lugares se han tomado medidas de las características de los bloques (dimensiones, orientación, litología), así como de los surcos (longitud) y los montones (altura) generados, y de las pendientes (orientación, pendiente) en las que se ubican. Se encuentran en zonas elevadas (1855-2116 m) con orientación entre norte y este, con pen-dientes más suaves (4 a 28º) en Vizcodillo que en el Alto Sil (16 y 40º), ya que en el primero de los lugares se encuentran en una superficie elevada por encima de los circos, mientras que en el Alto Sil están dentro de las laderas de los mismos. Su tamaño oscila entre 54 y los 440 cm de eje mayor, orientados preferentemente en el sentido de la ladera. Los surcos son relativamente cortos (menos de 1 m en varios casos), aunque algunos superan los 3 a 5 m, mientras que los montones presentan una altura modesta, entre 20 y 50 cm en la mayoría de los casos. Aunque la mayor parte parecen inactivos, hemos observado desplazamientos al menos en 2006 y 2015 en algunos de ellos, con movimientos de entre 10 y 35 cm, pudiendo ser movimientos relativamente rápidos. El movimiento ocasional de los bloques parece estar ligado a la existencia de unas condiciones térmicas adecuadas durante un año concreto, si bien aún se tienen pocos datos sobre esa relación. En todo caso, en uno de los bloques se observó que la congelación estacional del suelo superaba los 50 c

Evidencias de “permafrost” en el extremo sur de Los Andes (Tierra del Fuego) según el régimen térmico de los glaciares rocosos del Cerro Krund

Se presentan, por primera vez en Tierra del Fuego, los datos de temperatura del suelo y del aire de dos glaciares rocosos en el circo del Cerro Krund, en extremo sur de los Andes, a altitudes comprendidas entre 750 y 885 m durante los años 2009 y 2010. Los datos obtenidos, junto a las observaciones realizadas en la zona y la dinámica observada entre 2004 y 2010 evidencian que el más elevado es un glaciar rocoso activo, lo cual confirma la presencia de permafrost, para este sector de la Sierra de Alvear por encima de los 850 metros. Por debajo de esa cota, en la que se localiza el otro glaciar rocoso, no hay evidencias de permafrost, por lo cual lo consideramos relicto.We present air and ground thermal temperature data of some places located between 750 and 885 m.a.s.l. around two rock glaciers in the Cerro Krund cirque (Tierra del Fuego, Argentina) at altitudes between 750 and 885 m during the years 2009 and 2010. The data obtained, together with geomorphological observations and the dynamics observed between 2004 and 2010 show that the highest is an active rock glacier, which confirms the presence of permafrost for this sector of the Sierra de Alvear above 850 meters. Bellow this altitude, in the lower rock glacier, we could not found any permafrost evidences.peerReviewe

Coal pit lakes in abandoned mining areas in León (NW Spain): characteristics and geoecological significance

1-14 pMining activity introduces severe changes in landscapes and, subsequently, in land uses. One of the most singular changes is the existence of pit lakes, which occur in active and, more frequently, abandoned mines. Pit lakes are produced by water table interception when open-pit mines deepen. Their characteristics are highly variable, depending on the type of mine, the environment or the climate. In León province there is a long tradition of coal mining that dates back to the nineteenth century, and hundreds of open pits from the 1970s to 2018 have been opened, producing permanent landscape changes. This work analyses the main parameters, including morphological measurements, depth and pH values obtained from aerial photos and field work, of 76 coal pit lakes more than 30 m in length. The vast majority of these pit lakes were unknown until now and were not included in inventories or maps. The data obtained provide baseline knowledge that will allow, in the future, potential uses (storage of water for various uses, recreational use, wildlife habitat, and geological heritage sites) for these pit lakes and establish their importance as a new geoecological environment.S

Glaciokarst landforms in the Siera de los Grajos, Babia and Luna natural park (Cantabrian Mountains, NW Spain)

Landforms resulting from the interaction between paleo-glaciers and karst are studied by using the Sierra de los Grajos (Cantabrian Mountains) as a model. This area contains glacial landforms that have not interested geomorphologists due to their low altitude (Peña Castillo is about 1857 m a.s.l.), the absence of glacial cirques and the scarcity of large moraines. However, the prevalence of groundwater flow and chemical dissolution has favoured the preservation of glacial landforms. Lateral and frontal moraines show three main glacial stages and other minor glacier stabilization phases, with the paleo-ELA oscillating between 1650 and 1760 m. Moraines are combined with depressions and sinks resulting from subglacial karstic drainage. This convergence of forms and processes is an exception in the Cantabrian Mountains, where postglacial erosion has usually eroded the frontal moraines and the proglacial sediments. In the case of the Sierra de los Grajos, despite the underground drainage and preservation of many glacial deposits on karstic landforms, an outwash-plain was formed. These proglacial sediments and others from non-karstified areas filled the depressions of the preglacial terrain located at their edges. The main glaciokarstic landforms have been mapped and a sedimentological analysis of the outwash plain was made in order to reconstruct the glacial dynamics of this area.Key words: glaciokarst landforms, glacial geomorphology, karst geomorphology, geomorphological mapping, Cantabrian Mountains. Glaciokraški relief na območju Sierra de los Grajos v parku Babia in luna (Kantabrijsko gorovje, SZ Španija)Na območju Sierra de los Grajos (Kantabrijsko gorovje) smo raziskovali relief, ki je v preteklosti nastal z medsebojnim vplivanjem kraških in ledeniških procesov. Zaradi nizke nadmorske višine (Peña Castillo je le 1857 m nad morjem) ter odsotnosti velikih moren in krnic to območje geomorfologov do sedaj ni posebej zanimalo. Prav kraški procesi in z njimi povezano podzemno odtekanje so tu omogočili ohranitev ledeniških oblik. Bočne in čelne morene kažejo na tri glavne faze poledenitev in več manjših faz stabilizacije ledenikov z ravnovesno mejo (ELA) med 1650 in 1760 m.n.m. Morene so pogosto vezane na kraške globeli. Glaciokraške pojave najdemo le na tem območju Kantabrijskega gorovja, kjer je sicer poledeniška erozija odstranila čelne morene in proglacialne sedimente. Kljub podzemnemu odtoku in ohranitvi številnih ledeniških sedimentov na kraškem reliefu se je na Sierra de los Grajos oblikoval predledeniški vršaj (sander). Proglacialni sedimenti in sedimenti iz nekraških območij so zapolnili globeli v predledeniškem kraškem terenu. Kartiranje glaciokraških reliefnih in analiza sedimentov predledeniških vršajev sta nam omogočila rekonstrukcijo dinamike ledenika na obravnavanem območju.Ključne besede: glaciokraške reliefne oblike, ledeniška geomorfologija, kraška geomorfologija, geomorfološko kartiranje, Kantabrijsko gorovje, Španija.

Lugares de Interés Geológico de la provincia de Palencia (noroeste de España): un inventario y varios casos de estudio

p. 91-107En este trabajo se comentan los principales resultados del proyecto titulado “Estudio y catalogación de los Lugares de Interés Geológico (LIGs) de la provincia de Palencia” financiado por la Junta de Castilla y León, y realizado por un grupo de especialistas de la Universidad de León. Además, se exponen algunos casos concretos de los LIGs inventariados con el fin de profundizar en las diversas problemáticas que conlleva su gestión desde un punto de vista patrimonial y sugerir posibles soluciones a las mismas.S

Application of the Schmidt-hammer for relative-age dating of glacial and periglacial landforms in the Cantabrian Mountains (NW Spain)

[EN] A Schmidt hammer was applied for relative-age dating to 48 sites in 5 different massifs of the Cantabrian Mountains (NW Spain). The sample included glacial (moraines, erratics, and polished bedrock) and periglacial (rock glaciers, blockfields, and talus slopes) sites from the last glaciation to the present in different geomorphological contexts. The rebound (R) values agree with the morphostratigraphic reconstructions, showing progressively lower values for older deposits. Six stages from the Last Glacial Maximum to the present are inferred. The results differ according to the lithology: i) the quartzites showed higher R-values and very low weathering rates; ii) the granodiorites showed larger differences in R-values reflecting clearly age differences; iii) sandstones appear to be unsuitable for Schmidt hammer measurements in some areas; however, quartzite sandstones provide better results. The rock glaciers formed in different periods after deglaciation (i.e. just after the Last Glacial Maximum, Bölling/Allerød, Holocene), indicate a paraglacial dependence rather than climate-driven landforms. The sampled blockfields stabilized after the (almost) total deglaciation of the cirques, but their origin and significance in this mountainous area remain poorly understood.SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Glaciokarst landforms in the Sierra de los Grajos, Babia and Luna natural park (Cantabrian Mountains, NW Spain)

Producción CientíficaLandforms resulting from the interaction between paleo-glaciers and karst are studied by using the Sierra de los Grajos (Cantabrian Mountains) as a model. This area contains glacial landforms that have not interested geomorphologists due to their low altitude (Peña Castillo is about 1857 m a.s.l.), the absence of glacial cirques and the scarcity of large moraines. However, the prevalence of groundwater flow and chemical dissolution has favoured the preservation of glacial landforms. Lateral and frontal moraines show three main glacial stages and other minor glacier stabilization phases, with the paleo-ELA oscillating between 1650 and 1760 m. Moraines are combined with depressions and sinks resulting from subglacial karstic drainage. This convergence of forms and processes is an exception in the Cantabrian Mountains, where postglacial erosion has usually eroded the frontal moraines and the proglacial sediments. In the case of the Sierra de los Grajos, despite the underground drainage and preservation of many glacial deposits on karstic landforms, an outwash-plain was formed. These proglacial sediments and others from non-karstified areas filled the depressions of the preglacial terrain located at their edges. The main glaciokarstic landforms have been mapped and a sedimentological analysis of the outwash plain was made in order to reconstruct the glacial dynamics of this area.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (projects CGL2016-76215-R and CGL2015-65569-R