{"title":"地热通量对波兰西部和德国东部最后斯堪的纳维亚冰盖的影响","authors":"Izabela Szuman, Jakub Kalita, M. Ewertowski","doi":"10.1080/04353676.2018.1524711","DOIUrl":null,"url":null,"abstract":"ABSTRACT Geothermal heat flux (GHF) is heat supplied to the base of the ice sheet. It plays an important role in controlling ice sheet stability and affects basal temperatures, melting, and ice flow velocities. Here, we presume that the high GHF, as high as c. 110 mW m−2 over W Poland and more than 90 mW m−2 over E Germany, might have been one of the factors influencing the last Scandinavian ice sheet behaviour. For the analysed case, a GHF of 80 mW m−2 is more or less at the level of upward heat conduction. The difference in basal temperatures between areas with higher and lower GHF due to ice insulation was about 3–4oC. The minimum heat flow needed to reach the pressure melting point for the SIS beneath the ice streams in central west Poland was about 60 mW m−2. Possible interpretations would be that any excesses of heat participated in the meltwater production (by over 8 mm) that was at least partly stored subglacially due to the low-permeable bed and lack of channelised drainage traces, and maintained a fast ice streaming or enable reaching the pressure melting point or higher temperatures could counteract the freezing present near the ice sheet margin. The fast ice flow over central west Poland is confirmed by sedimentary and geomorphological evidence (e.g. mega-scale glacial lineations).","PeriodicalId":55112,"journal":{"name":"Geografiska Annaler Series A-Physical Geography","volume":"39 1","pages":"388 - 403"},"PeriodicalIF":1.4000,"publicationDate":"2018-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"7","resultStr":"{\"title\":\"The impact of geothermal heat flux on the last Scandinavian ice sheet over W Poland and E Germany\",\"authors\":\"Izabela Szuman, Jakub Kalita, M. Ewertowski\",\"doi\":\"10.1080/04353676.2018.1524711\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"ABSTRACT Geothermal heat flux (GHF) is heat supplied to the base of the ice sheet. It plays an important role in controlling ice sheet stability and affects basal temperatures, melting, and ice flow velocities. Here, we presume that the high GHF, as high as c. 110 mW m−2 over W Poland and more than 90 mW m−2 over E Germany, might have been one of the factors influencing the last Scandinavian ice sheet behaviour. For the analysed case, a GHF of 80 mW m−2 is more or less at the level of upward heat conduction. The difference in basal temperatures between areas with higher and lower GHF due to ice insulation was about 3–4oC. The minimum heat flow needed to reach the pressure melting point for the SIS beneath the ice streams in central west Poland was about 60 mW m−2. Possible interpretations would be that any excesses of heat participated in the meltwater production (by over 8 mm) that was at least partly stored subglacially due to the low-permeable bed and lack of channelised drainage traces, and maintained a fast ice streaming or enable reaching the pressure melting point or higher temperatures could counteract the freezing present near the ice sheet margin. The fast ice flow over central west Poland is confirmed by sedimentary and geomorphological evidence (e.g. mega-scale glacial lineations).\",\"PeriodicalId\":55112,\"journal\":{\"name\":\"Geografiska Annaler Series A-Physical Geography\",\"volume\":\"39 1\",\"pages\":\"388 - 403\"},\"PeriodicalIF\":1.4000,\"publicationDate\":\"2018-09-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"7\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Geografiska Annaler Series A-Physical Geography\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1080/04353676.2018.1524711\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOGRAPHY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geografiska Annaler Series A-Physical Geography","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1080/04353676.2018.1524711","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}
引用次数: 7
摘要
地热热通量(GHF)是提供给冰盖底部的热量。它在控制冰盖稳定性和影响基础温度、融化和冰流速度方面起着重要作用。在这里,我们假设高GHF(波兰西部高达c. 110 mW m - 2,德国东部超过90 mW m - 2)可能是影响斯堪的纳维亚冰盖行为的因素之一。对于所分析的情况,80 mW m−2的GHF或多或少处于向上热传导水平。高GHF区与低GHF区由于冰绝热造成的基温差异约为3 ~ 4℃。波兰中西部冰流下的SIS达到压力熔点所需的最小热流约为60 mW m - 2。可能的解释是,任何过量的热量都参与了融水的产生(超过8毫米),这些融水至少部分储存在冰下,这是由于低渗透性的床和缺乏水道化的排水痕迹,并保持了快速的冰流,或使达到压力熔点或更高的温度,可以抵消冰盖边缘附近的冻结。沉积和地貌证据(如超大尺度冰川线)证实了波兰中西部的快速冰流。
The impact of geothermal heat flux on the last Scandinavian ice sheet over W Poland and E Germany
ABSTRACT Geothermal heat flux (GHF) is heat supplied to the base of the ice sheet. It plays an important role in controlling ice sheet stability and affects basal temperatures, melting, and ice flow velocities. Here, we presume that the high GHF, as high as c. 110 mW m−2 over W Poland and more than 90 mW m−2 over E Germany, might have been one of the factors influencing the last Scandinavian ice sheet behaviour. For the analysed case, a GHF of 80 mW m−2 is more or less at the level of upward heat conduction. The difference in basal temperatures between areas with higher and lower GHF due to ice insulation was about 3–4oC. The minimum heat flow needed to reach the pressure melting point for the SIS beneath the ice streams in central west Poland was about 60 mW m−2. Possible interpretations would be that any excesses of heat participated in the meltwater production (by over 8 mm) that was at least partly stored subglacially due to the low-permeable bed and lack of channelised drainage traces, and maintained a fast ice streaming or enable reaching the pressure melting point or higher temperatures could counteract the freezing present near the ice sheet margin. The fast ice flow over central west Poland is confirmed by sedimentary and geomorphological evidence (e.g. mega-scale glacial lineations).
期刊介绍:
Geografiska Annaler: Series A, Physical Geography publishes original research in the field of Physical Geography with special emphasis on cold regions/high latitude, high altitude processes, landforms and environmental change, past, present and future.
The journal primarily promotes dissemination of regular research by publishing research-based articles. The journal also publishes thematic issues where collections of articles around a specific themes are gathered. Such themes are determined by the Editors upon request. Finally the journal wishes to promote knowledge and understanding of topics in Physical Geography, their origin, development and current standing through invited review articles.