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Lacustrine Records of Holocene ENSO Variability
Christopher Moy1 Donald Rodbell2 Geoffrey Seltzer3 Ursula Roehl4 David
Anderson1
1NOAA Paleoclimatology Program
2Geology Dept., Union College
3Dept. Of Earth Sciences, Syracuse University
4University of Bremen
Background
• Sediment core retrieved from L. Pallcacocha displayed abundant light-colored clastic laminae.
• Rodbell et al. (1999) hypothesized that the clastic laminae were deposited during El Nino-induced alluviation events in the drainage basin.
• However, discontinuity and lack of a sediment-water interface precluded investigation of millennial-scale variability.
Objective:
• Utilize a new continuous sediment core and identify the frequency components with wavelet analysis
Geotek Linescan Camera
CORTEX XRF Scanner – Univ. of Bremen
Jansen et al. (1998)
Jansen et al. (1998)
Age Models
Constant Carbon Accumulation Model:
-Distributes age based on carbon content of sediment
Event Model:
-All laminae assigned a value of 6 months based on Rio Chira discharge data
Both models assign higher sedimentation rates to the light-colored laminae
Relationship to Modern ENSO
210 Pb Years (AD)
light
dar k
Ave
rag
e G
ray
Sc
ale
(St d
. D
e v.
Un
its )
2000 1980 1960 1940 1920 1900 1880 1860
Linescan Results
0 2000 4000 6000 8000 10000 12000 140000
50
100
150
200
250R
ed
Co
lor
Inte
nsi
ty
Age (cal yr BP)
0 2000 4000 6000 8000 10000 12000 140000
10
20
30
40
Age (cal yr BP)
Eve
nts
* 1
00 y
r -1
XRF Results
Age (cal yr BP)
0 2000 4000 6000 8000 10000 120000
50
100
150
200
250
Re
d C
ol o
r In
ten
s it y
(K +
TI )
/ F
e
0 2000 4000 6000 8000 10000 120000
0.05
0.1
0.15
0.2
0 2000 4000 6000 8000 10000Time (cal yr BP)
48
163264
128256512
10242048
Per
iod
( yea
rs)
0 2000 4000 6000 8000 10000Time (cal yr BP)
8163264
128256512
1024204840968192
Per
iod
( yea
rs)
-50
0
50
100
150
200
0 2000 4000 6000 8000 10000Time (cal yr BP)
Re
d C
olo
r In
tens
ity
80
21
3
0.5
137
23
5
ENSO Model Comparison
Clement et al. (2000)
0 2000 4000 6000 8000 10000 12000 140000
5
10
15
20
Age (cal yr BP)
0 2000 4000 6000 8000 10000 12000 140000
10
20
30
Nu
mb
er o
f W
arm
Eve
nts
* 1
00
yr-
1
Nu
mb
er
of
Eve
nts
* 1
00
yr-
1
Number Study Record Time Span Resolution
1 North Australia; McGlone et al. (1992) and
Shulmeister and Lees (1995)
Lake Sediment: Pollen
Holocene Inter-Decadal
2 Great Barrier Reef, Australia; Gagan et al. (1998)
Coral: Sr/Ca and 18O
25 Years; ~5400 cal yr BP
Annual
3 Northern New Guinea, Tudhope et al. Coral: 18O 49 Years at ~6500 cal yr BP and ~90 years at 2000-3000 cal yr BP
Annual
4 Ecuador, Rodbell et al. (1999) Moy (2000) Lake Sediment: Grayscale and Color
~12,000 Years Sub-Decadal
5 Coastal Peru, Sandweiss et al. (2001) Midden: Mollusks Holocene Discontinuous
Image from Cole (2001)
Future Work - Laguna Fondococha
0 50 100 150 200 250 300 350 4000
2000
4000
6000
8000
0 50 100 150 200 250 300 350 4000
200
400
600
0 50 100 150 200 250 300 350 4000
50
100
150
200
250
Depth (cm)
K (
cps)
Ti (
cps)
Fe
(cps
)
Conclusions:
•Gradual increase in ENSO event frequency through the Holocene
Driven by orbitally-induced changes in insolation
•Millennial-scale variability centered on 2,000 yrs
•Centennial to ENSO band variance exhibited in the most recent 6,000 yrs of the record
XRF Results
0 2000 4000 6000 8000 10000 120000
100
200
300
K (
cps)
Fe
(cp
s)
0 2000 4000 6000 8000 10000 120000
2000
4000
6000
8000
0 2000 4000 6000 8000 10000 120000
20
40
60
80
Ti (
cps)
Age (cal yr BP)
comp
-2
-1
0
1
2
3
4
0 2000 4000 6000 8000 10000 12000
Pal
lcac
ocha
Fil
tere
d X
RF
Com
posi
te
Com
parison to IRD
events in the N. A
tlantic
Comparison to IRD events in the N. Atlantic
-50
0
50
100
150
200
0 2000 4000 6000 8000 10000Time (cal yr BP)
Re
d C
olo
r I n
t ens
ity
LIA 1 2 3 4 5 6 7 8
Pacific Basin Proxy Records
ENSO Band
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