Rapid transformation of the Arctic system: tephrostratigraphic and paleoenvironmental records from relict permafrost

预计到下个世纪的变暖将在高纬度地区表现得最为强烈。这些地区对环境变化高度敏感，在全球气候系统中发挥着重要作用。由于与北极系统相关的复杂反馈，未来对高纬度地区的影响尚不清楚。然而，可以通过开发古记录来检验预测的可靠性，这些记录记录了过去气候间隔比现在更暖或更暖的影响，或过去50万年的间冰期。这些地点存在于育空地区的内部和北部育空地区以及邻近的阿拉斯加。这项研究利用并进一步发展了该地区远端火山灰床（tephra）的记录，从而可以确定大面积的离散时间线，并确定过去间冰期的年龄。总的来说，这提供了一种方法，可以利用过去地球气候系统的自然实验来测试未来高纬度地区变暖的全球气候模型。本研究以申请人在加拿大西北部和阿拉斯加东部建立的项目为基础。

Projected warming through the next century will be most strongly expressed in high latitude areas. These areas are highly sensitive to environmental change and play an important role in the global climate system. Future impacts at high latitudes are not well understood due to the complex feedbacks associated with the Arctic*system. The reliability of projections can be tested, however, through developing paleo-records which document the impact of past climate intervals as warm or warmer than present, or interglacials of the past 500,000 years. These sites exist in the interior of Yukon and northern Yukon Territory and adjacent Alaska. This research makes use of, and further develops the record of distal volcanic ash beds (tephra) in this region which allows discrete timelines over large areas to be identified and ages of past interglacials established. Collectively, this provides a means to test global climate models of future warming at high latitudes using the natural experiments of the earth's climate system of the past. This research builds on an established program by the applicant in northwestern Canada and eastern Alaska.