Topic_8____Climate_Change_III

Topic_8____Climate_Change_III - Topic 8: Climate Change...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Topic 8: Climate Change Through Time III: Rapid Climate Change Part 3 – Rapid climate change Outline A. Reorganization of ocean circulation Geologic records of environmental change show large climate changes in decades! B. ENSO Changes in tropical oceans drive periodic global changes on 2-10 year time scale ________________________________________________________________ __________________________ 1 A. Rapid climate flickers driven by the oceanic circulation 'conveyor belt' Major points * Ice Cores are excellent records of environmental change * Climate can change by 5-10 degrees C in decades * These rapid changes may be due to changes in the global conveyor belt of oceanic circulation 1. Glacial-interglacial transitions – How rapid and how smooth were these? When was the Last Glacial Maximum? Ice core records of oxygen isotope composition and dust content of ice layers are used as an indicator of temperature and climate in the past.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2. The geologic record indicates that the warming from the last glacial interval to the present interglacial interval (Pleistocene-Holocene transition) was interrupted by several large and abrupt plunges back into cold periods. The driving mechanism for these rapid climate changes is not fully understood, but evidence points to a major role for the oceanic thermohaline conveyor belt. Warmer δ 18 O of ice Thousands of years before present Glacial Interglacial
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
3. In deep-sea cores in the Atlantic Ocean, ice-rafted debris provides evidence for several major melting events during the end of the Pleistocene (~ 40,000 to 10,000 years ago) that are coincident with the plunges back into cold periods. One hypothesis that has been proposed is as follows. Each melting event would send a lid of cold freshwater into North Atlantic, which would inhibit the thermohaline
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/02/2009 for the course GEO 302C taught by Professor Yang during the Spring '08 term at University of Texas at Austin.

Page1 / 22

Topic_8____Climate_Change_III - Topic 8: Climate Change...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online