課程概述 |
Course Description The aim of this course is to give the students the understanding necessary to interpret environmental and paleoclimatic records obtained from lake sediments. Terrestrial records of climate change play an increasingly important role in climate science to test numerical climate model predictions, and to provide analogies for future environmental change. Lakes have several advantages over other terrestrial climate archives (such as e.g., speleothems, ice cores or tree rings): Lakes can be found on all continents and in most environments; lakes often have high accumulation rates - resulting in high-resolution archives; lakes are often present for tens of thousands of years, providing records reaching back to the last glacial maximum or beyond; lakes are relatively easy to access, and sampling costs are considerably lower than for marine records. However, despite all their advantages, lakes are also complex systems where the proxy records are influenced by factors unrelated to environmental change, such as lake formation and lake evolution. Therefore, to be able to properly interpret climate archives from lakes, we must understand how the lake system works and evolves over time. In this course, we will learn how lakes form, how different lake systems evolve over time, and how climatic and environmental changes are recorded in the lake archives can be interpreted. The course includes a 3-day field trip from September 28th to 30 to Cuifeng Lake to learn core sampling and lake surveying.
本課程目標是培養學生具有足夠能力以湖泊沈積物之紀錄來探討古環境氣候變遷。陸源沈積物紀錄在探討氣候變遷上扮演重要角色,除了用來驗證數值氣候模式預測外,也提供未來變化趨勢的類比。湖泊與其它陸源沈積物(如石筍,冰芯,或樹輪)相較有下列優點:在大部份環境下分佈範圍幾乎可涵蓋所有陸地區域;湖泊的高沈積速率使之具有高解析度之優點;湖泊沈積物記錄可長達幾萬年,甚至末次冰盛期 (LGM) 以前;湖泊沈積物取得相對容易,比起海洋岩芯的採樣費用低得多。儘管具有上述優點,來自湖泊沈積物的代用指標會受到如湖泊自身形成和演化過程等與氣候變化不相關之因素影響,而使湖泊系統的複雜性增加。因此,要能夠正確地利用湖泊沈積物探討氣候變化前,必須先瞭解湖泊系統隨時間的演化過程。在本課程中,學生將會瞭解湖泊的成因,不同湖泊系統隨時間的演化過程,以及如何運用湖泊沈積物中取得之代用指標來探討過去氣候與環境變化。 9/28-9/30將會有為期三天的古湖泊學野外採樣調查,地點為宜蘭三星池與翠峰湖。 |