Environmental Variations during the Holocene in Patagonia Icefield, South America

该研究项目的目的是建立南美洲巴塔哥尼亚全新世的环境变化。我们选择了两个冰川，北巴塔哥尼亚冰原的冰川勘探冰川(NPI)和巴塔哥尼亚冰原南部的冰川佩里托·莫雷诺(SPI)，并在2003-2005年期间派出了两个不同的考察队进行实地考察。以下是我们的活动和主要发现的摘要。冰川勘探者位于NPI的东北角。在这个冰川的前面是一个巨大的冰川末端，许多NPI冰川都有类似的TMS特征。因此，确定该冰川的年龄对于确定北冰洋全新世冰川推进具有重要意义。根据6次木片测年和树木年轮计数，推测该冰川形成于14至17世纪的小冰期。为了了解冰川动力学，以及阐明冰川的特征…为了更多地了解冰川，我们测量了南半球夏季(两个季节)和南半球冬季(一个季节)的冰川流量。夏季，冰川流量为7-11厘米/天。据推测，冰口附近的冰川厚度约为260-300米。我们还在冰川及其周围建立了几个气象站。2004年12月开始对出水口进行水文测报，首次实现了全年水文测报。莫雷诺冰川为崩解冰川，年平均气温为7.4℃m，降水量约为3 300 mm，比流量约为6 600 mm，冰川崩解的变化往往与气候变化无关。因此，了解导致冰川变化的因素是很重要的。因此，在冰川Perito Moreno，我们用自动记录的GPS测量了冰川表面的海拔、应变、崩解活动、消融、湖平面、冰川流量和温度，以澄清冰川崩解量和冰川动力学之间的关系。冰川表面在2004-2005年间下降，我们观察到消融区中部附近的应急速度降低。冰川中部附近的水流速度为0.8-1.2米/天，而在冰川口部，许多地方的流速通常为1.5米/天。尽管我们测量了许多可能影响冰川动力学的因素，但我们没有发现任何与冰川崩解活动有明确关系的因素。较少

The objective of this research project was to establish Holocene Environmental Changes in Patagonia, South America. We have selected two glaciers, Glaciar Exploradores from the Northern Patagonia Icefield (NPI), and Glaciar Perito Moreno from the Southern Patagonia Icefield (SPI) and sent two separate parties for field investigation in the period 2003-2005. The following is the summary of our activities and major findings.Glaciar Exploradores is located on the northeast corner of the NPI. In front of this glacier is located a big terminal moraine, and similar TMs characterize many NPI glaciers. Therefore, determining the age of this moraine is important to establish the Holocene glacier advance in the NPI. From six datings of wood pieces and tree ring counts, it was inferred that this moraine was formed sometime during the Little Ice Age, between 14^<th> and 17^<th> century. In order to understand glacier dynamics that constructed this terminal moraine as well as to elucidate character … More istics of the glacier, we measured glacier flow in austral summer (two seasons) and austral winter (one season). During summer, glacier flow was 7-11 cm/day. The glacier thickness near the snout was deduced to be about 260-300 m. We also set up several meteorological stations on and around the glacier. We started hydrological measurement of outlet stream in Dec. 2004 and we succeeded to obtain a year round record for the first time. The average annual mean temperature near the snout was 7.4℃m, precipitation was about 3300 mm, and specific outflow of stream was about 6600 mm.Glaciar Perito Moreno is a calving glacier, and the variation of a calving glacier is often not directly related to climate changes. So it is important to know the factors that cause the glacier variation. Therefore, at Glaciar Perito Moreno, we measured glacier surface elevation, strain, calving activities, ablation, lake level, glacier flow with automated recording GPS, and temperature, in order to clarify the relationship between the amount of calving and glacier dynamics. The glacier surface lowered between 2004 and 2005, and we observed decrease in the emergency velocity near the middle of the ablation area. Flow speed near the middle of the glacier was 0.8-1.2 m/day, while at the snout it was often 1.5 m/day at many spots. Although we have measured many factors that would affect glacier dynamics, we could not find any firm relationship with calving activities. Less