Environmental Variations during the Holocene in Patagonia Icefield, South America

该研究项目的目的是建立南美巴塔哥尼亚全新世环境变化。我们选择了两个冰川，即来自北方巴塔哥尼亚冰原（NPI）的Glaciar Exploradores和来自南方巴塔哥尼亚冰原（SPI）的Glaciar佩里托莫雷诺，并派出两个独立的小组在2003-2005年期间进行实地调查。以下是我们的活动和主要发现的摘要。Glaciar Exploradores位于NPI东北角。在这个冰川的前面是一个大的终碛，类似的TM特征许多NPI冰川。因此，确定该冰碛的年龄对确定NPI全新世冰川推进具有重要意义。根据6次木片和树木年轮的测年结果，推测该冰碛物形成于小冰期（14 <th>~ 17<th>世纪）。为了了解构成这一终碛的冰川动力学， ...更多信息 冰川的动态，我们测量了南夏（两季）和南冬（一季）的冰川流量。在夏季，冰川流量为7-11厘米/天。据推测，冰川鼻端的冰川厚度约为260-300 m。我们还在冰川上和周围建立了几个气象站。我们于2004年12月开始对出口河流进行水文测量，并首次成功地获得了全年记录。冰川佩里托莫雷诺是一个裂陷冰川，裂陷冰川的变化往往与气候变化没有直接关系。因此，了解引起冰川变化的因素是非常重要的。因此，在Glaciar佩里托莫雷诺，我们测量了冰川表面海拔，应变，崩解活动，消融，湖面，冰川流量与自动记录GPS和温度，以澄清崩解量和冰川动态之间的关系。2004年至2005年之间的冰川表面降低，我们观察到的紧急速度减少消融区的中间附近。冰川中部附近的流速为0.8-1.2米/天，而在鼻端，许多地方的流速通常为1.5米/天。虽然我们已经测量了许多影响冰川动力学的因素，但我们无法找到与产犊活动的任何确定关系。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