De los cambios globales –climáticos, tecnológicos y societales– emergen nuevos riesgos que implican tomar en cuenta múltiples escalas espaciales y temporales, así como a una diversidad de actores. ...Para hacer frente a ello, es menester desarrollar la participación de los ciudadanos y ciudadanas, reforzar la dimensión territorial y tomar en consideración la vulnerabilidad de los individuos. Este texto tiene por objeto comprender los efectos de tales evoluciones en la ergonomía de la actividad, llamada a renovar sus conceptos y métodos de intervención sin perder su especificidad. Han de establecerse nexos con las ciencias ambientales y la ciencia política. Dos casos ilustran la evolución del modelo de análisis de la actividad : las mujeres guías de alta montaña y los actores de la gestión del riesgo de degradación del permafrost. El cambio climático lleva a la ergonomía a incluir en sus modelos dimensiones sociales y redes de actores.
We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost ...region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon–climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km² for the RCP4.5 climate and between 6 and 16 million km² for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbon varied between 66-Pg C (1015-g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. This assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon–climate feedback.
A continuación, el autor se centra en el estudio de las características climáticas de estas islas, definidas por un clima polar oceánico con temperaturas medias anuales de -2 a -3°C a nivel del mar ...(bastante menos bajas que en el interior del continente), y precipitaciones anuales comprendidas entre 800 y 500 mm (mucho más abundantes, por tanto, que en la Antártida continental). Las mejores obras de la Geografía son siempre el fruto de un contacto directo con la realidad que se describe; sin embargo, para la mayor parte de quienes se dedican o simplemente se interesan por la Geografía, conocer de primera mano el ?continente sin dueño? (tal como lo definiera Eduardo Martínez de Pisón), seguirá siendo un sueño. Aquellas personas interesadas en los entornos antárticos, tienen un fantástico libro a través del cual soñar esos panoramas de hielo y roca y comprender su evolución natural inducida por procesos locales o de alcance global, y siguiendo el rastro al interés que este territorio ha despertado en el ser humano, a través de la Historia.
In continuous permafrost regions, pathways for transport of sub‐permafrost groundwater to the surface sometimes perforate the frozen ground and result in the formation of a pingo. Explanations ...offered for the locations of such pathways have so far included hydraulically conductive geological units and faults. On Svalbard, several pingos locate at valley flanks where these controls are apparently lacking. Intrigued by this observation, we elucidated the geological setting around such a pingo with electrical resistivity tomography. The inverted resistivity models showed a considerable contrast between the uphill and valley‐sides of the pingo. We conclude that this contrast reflects a geological boundary between low‐permeable marine sediments and consolidated strata. Groundwater presumably flows toward the pingo spring through glacially induced fractures in the strata immediately below the marine sediments. Our finding suggests that flanks of uplifted Arctic valleys deserve attention as possible discharge locations for deep groundwater and greenhouse gases to the surface.
Plain Language Summary
In the High Arctic, considerable amounts of greenhouse gasses are stored below permanently frozen ground (permafrost) in deep groundwater systems. The permafrost usually retains these greenhouse gasses and groundwaters deep in the subsurface, but flow to the surface and atmosphere can take place where unfrozen holes form hydrological pathways through the permafrost. The common explanations offered for the locations of such pathways include geological layers and faults that are permeable for groundwater flow. However, on Svalbard, several active and relict groundwater springs locate at valley flanks where none of the common explanations seem suitable. Intrigued by this observation, we investigated the geological setting around such a spring with measurements of the electrical resistivity of the subsurface. In line with existing geological knowledge, our results show that the spring locates exactly at the boundary between low‐permeable marine valley sediments and older consolidated sediments. Groundwater presumably flows toward the spring through glacially induced fractures in the consolidated sediments. Our finding suggests that flanks of uplifted Arctic valleys deserve attention as possible outflow locations for deep groundwater and greenhouse gasses to the surface and atmosphere.
Key Points
Electrical resistivity surveys link the location of a pingo spring to the transition between marine valley sediments and consolidated strata
Groundwater flow toward the pingo spring most likely follows glacially induced fractures in consolidated strata produced during glaciation
Flanks of uplifted Arctic valleys deserve attention as discharge locations for sub‐permafrost groundwater and dissolved greenhouse gases
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