Droughts - Extreme Events: A Physical Reconstruction and Risk Assessment - page 38

0

5

10

A

15

0

5

10

20

B

25

0 1 2 3 5 6 7 8

30
-29

4

-28

C

-27

-26

-25

-24
-30

D

-29
-28

-27

-26

-25

-24

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000

Age (Calendar yrs BP)

13 Crecord from a peat bog on the Tibetan Plateau
highlighting the variability and abrupt nature of changes in the Indian Summer
Monsoon and the close correlation with the record of ice rafting events in the
NorthAtlantic. The numbers in grey columns refer to the sequence of ice rafting
events starting with the Little Ice Age at 0 (from Hong et al ., 2003).

Figure 2.9. 12 000 year long

Oxygen isotopes

Oxygen isotopes also provide useful information about palaeoclimates.
The ratio of

16 Oinsediments,various precipitates and animal tests or
skeletons can be used to estimate precipitation levels during past climates. In
lacustrine environments, the oxygen isotope composition in carbonates reflects

18 O/