Greenland Ice Sheet History Since the Last Glaciation
Greenland Ice Sheet History Since the Last Glaciation
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自末次冰期以来格陵兰冰盖的历史
DOI：
10.1016/0033-5894(74)90038-6
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发表时间：
1974
影响因子：
2.3
通讯作者：
A. Weidick
中科院分区：
文献类型：
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作者：
Norman W. Ten Brink;A. Weidick
内陆冰缘的位置在威斯康星-乌尔姆冰期晚期（约1000年）。15，000年BP）可能以离岸银行（海底冰碛？）在戴维斯海峡。自威斯康星-维尔姆晚期以来的内陆冰历史可分为四个主要阶段：（1）从离岸岸相对缓慢地后退，平均速度约为1 km/100 yr，直到约2000年。10，000年BP（新仙女木？）当时塔塞尔卡特冰碛系统是由一次再循环形成的。(2)在约9500 yr BP，后退速率显著增加到约3 km/100 yr，虽然约100 km的后退发生在约9500 yr BP。6500年BP，它是由频繁的区域再扩张的内陆冰，形成广泛的冰碛系统在约打断。8800-8700年BP（Avatdleq-Sarfartôq冰碛），8400-8100年BP（Angujârtorfik-Fjord冰碛），7300年BP（Umartvoult冰碛）和7200-6500年BP（Keglen-Mt，Keglen冰碛）。(3)6500和700年BP之间，不连续的冰缘沉积物和冰解体的功能，在撤退过程中形成，这可能一直持续到冰缘附近或落后于其目前的位置约。6000年BP。大部分不连续冰缘沉积发生在距现今冰缘5-10 km范围内，可能是由约1000年的两次主要再进活动形成的。4800-4000年BP和2500-2000年BP。(4)因为在CA的一个readvance。700年BP，内陆冰缘经历了几次小的后退和readvances导致许多紧密间隔的冰碛物的沉积约3公里的冰缘。年轻的冰碛物很难在区域上相互关联，但几个单独的冰碛物具有以下近似年龄：公元1650年，1750年和1880- 1920年。格陵兰西部的内陆冰波动与格陵兰东部和加拿大北极东部的全新世冰川事件非常密切相关。大面积冰川活动的这种相似性强烈表明，广泛的气候变化是全新世冰川波动的直接原因。此外，内陆冰缘的历史进展之后，轻微的温度下降不超过几十年，和18 O数据从格陵兰冰芯表明，轻微的温度下降经常发生在整个全新世。因此，我们得出结论，建设的主要全新世冰碛系统在西格陵兰是由轻微的温度下降，从而降低消融率，从而产生实际上立即进步的冰盖边缘，但不一定会影响长期的平衡冰盖。
The position of the Inland Ice margin during the late Wisconsin-Würm glaciation (ca. 15,000 yr BP) is probably marked by offshore banks (submarine moraines?) in the Davis Strait. The history of the Inland Ice since the late Wisconsin-Würm can be divided into four principal phases: (1) Relatively slow retreat from the offshore banks occurred at an average rate of approximately 1 km/100 yr until ca. 10,000 yr BP (Younger Dryas?) when the Taserqat moraine system was formed by a readvance. (2) At ca. 9500 yr BP, the rate of retreat increased markedly to about 3 km/100 yr, and although nearly 100 km of retreat occurred by ca. 6500 yr BP, it was punctuated by frequent regional reexpansions of the Inland Ice that formed extensive moraine systems at ca. 8800-8700 yr BP (Avatdleq-Sarfartôq moraines), 8400-8100 yr BP (Angujârtorfik-Fjord moraines), 7300 yr BP (Umîvît moraines), and 7200-6500 yr BP (Keglen-Mt, Keglen moraines). (3) Between 6500 and 700 yr BP, discontinous ice-margin deposits and ice-disintegration features were formed during retreat, which may have continued until the ice margin was near or behind its present position by ca. 6000 yr BP. Most of the discontinuous ice-margin deposits occur within 5–10 km of the present ice margin, and may have been formed by two main phases of readvance at ca. 4800-4000 yr BP and 2500-2000 yr BP. (4) Since a readvance at ca. 700 yr BP, the Inland Ice margin has undergone several minor retreats and readvances resulting in deposition of numerous closely spaced moraines within about 3 km of the present ice margin. The young moraines are difficult to correlate regionally, but several individual moraines have the following approximate ages: A.D. 1650, 1750, and 1880–1920.Inland Ice fluctuations in West Greenland were very closely paralleled by Holocene glacial events in East Greenland and the eastern Canadian Arctic. Such similarity of glacier behavior over a large area strongly suggests that widespread climatic change was the direct cause of Holocene glacial fluctuations. Moreover, historical advances of the Inland Ice margin followed slight temperature decreases by no more than a few decades, and 18O data from Greenland ice cores show that slight temperature decreases occurred frequently throughout the Holocene. Therefore, we conclude that construction of the major Holocene moraine systems in West Greenland was caused by slight temperature decreases, which decreased rates of ablation and thereby produced practically immediate advances of the ice sheet margin, but did not necessarily affect the long-term equilibrium of the ice sheet.