Reconstruction of the climatic changes from borehole temperature and tree rings in the Kamchatka Peninsula

我们用地热法和树状年代学两种独立的方法估计了堪察加半岛过去几个世纪的气候变化。作为地热法的研究，我们在2000年至2002年进行了三次探险，重复测量了53℃附近10个钻孔的温度分布。根据其中6个钻孔的温度分布可以重建地表温度历史，表明在过去的50到100年里，温度显著上升了1~2K。我们还在三个钻孔的特定深度进行了长期温度监测，并观察到了时间变化，表明存在小尺度水对流和地下水流量的季节性变化。地下水样本取自记录温度的钻孔，地表水样本也采集自河流。对地下水和地表水的地球化学和稳定同位素特征进行了e…分析。更重视地下水流动对研究区地下温度和气候重建的影响。在2000年勘察的基础上，根据2001年在Kronotsky国家公园自然生长的兴安落叶松的年轮样本，建立了代表堪察加中部的422年轮宽指数的长达422年的年表。对观测气候年表的响应分析表明，与初夏气温有显著的相关性。根据树状年代学及其对气候的响应，重建的温度可追溯到公元1624年，显示出过去130年的总体变暖趋势和年代际周期的周期性振荡。这一长期趋势与钻孔温度剖面的结果是一致的。还对韩国的三口井和琵琶湖沿岸的一口井的钻孔温度剖面进行了地表温度历史的重建。在韩国，估计的气温变化与附近气象站的气温数据一致。琵琶湖的表面温度历史似乎反映了过去5000年来当地环境的变化。较少

We estimated climate changes in the Kamchatka Peninsula over the last few centuries with two independent, geothermal and dendrochronological methods.As studies with the geothermal method, we conducted three expeditions in 2000 to 2002 to make repeated measurements of temperature profiles in ten boreholes around 53 degN. The ground surface temperature history could be reconstructed from the temperature profiles in six of the boreholes, demonstrating a significant temperature increase of 1 to 2 K for the last 50 to 100 years. We also made long-tem temperature monitoring at some specific depths in three boreholes and observed temporal variations which suggest the existence of small-scale water convections and seasonal changes in groundwater flow. Groundwater samples were taken from the boreholes where temperature logging was made and surface water samples were also collected from rivers. Geochemical and stable isotope characteristics of the groundwater and surface water were analyzed to e … More valuate the effects of the groundwater flow on the subsurface temperature and climate reconstruction in the study areas.A 422-year long chronology of ring-width indices representing central Kamchatka was established from tree-ring cores sampled from Larix gmerinii growing natural in the Kronotsky National Park in 2001 based on reconnaissance in 2000. Response analysis of the chronology against observed climate revealed a significant correlation with early-summer temperature. The reconstructed temperature extending back to A.D. 1624 based on the dendrochronology and its response to climate, revealed a general warming trend over the last 130 years and a cyclic oscillation of decadal period. The long-term trend is consistent with the result from the borehole temperature profiles.Reconstruction of the ground surface temperature history from borehole temperature profiles was also made for three wells in Korea and one well on the coast of Lake Biwa. In Korea, the estimated temperature changes are consistent with the air temperature data at nearby meteorological stations. The surface temperature history by Lake Biwa appears to reflect local environmental changes for the last 5000 years. Less