Dunbar, R

Fink, D

Fruffel, E

Gutierrez, D

Rein, B

Salvatteci, R

Sanchez-Cabeza, JA

Sifeddine, A

Skilbeck, G

English

ANSTO Publications Online

REGIONAL CONTROLS ON HOLOCENE 
SEDIMENTATION PATTERNS ALONG THE 
PERU CONTINENTAL MARGIN;  
LONG TERM IMPLICATIONS FOR EL NIÑO-SOUTHERN 
OSCILLATION 
Greg  SKILBECK,  Dimitri  GUTIERREZ, Bert  REIN,  
Abdel  SIFEDDINE, Renato SALVATTECI, David FINK, Ellen DRUFFEL,  
Joan-Albert SANCHEZ-CABEZA, Rob DUNBAR 
 
IAEA CN-186  
28 Mar – 1 Apr 2011 
Monaco 
Workshop 1: Isotopes in Marine Climate Studies   
ENSO & Peru Margin Sediments 
El Niño-Southern Oscillation  (ENSO) 
ENSO & Peru Margin Sediments 
Outline 
Where is our understanding now? 
“New” data 
• Radiocarbon re-calibration 
• Pattern of sediment accumulation 
• Geochemical evidence 
Oceanographic implications 
ENSO & Peru Margin Sediments 
Is this (interannual) ENSO? 
The GUIDELINE 
Modern (instrumental) ENSO recurrence 2 – 7 years 
over ~130 years with modal frequency ~5+ yr 
 
The EVIDENCE 
Geochemistry (multiproxy, consistent, but incomplete  
                                      time series) 
Image Analysis (resolution 0.1 mm per pixel; interannual 
                                         aliasing precluded, pixels per year?) 
Layer Counting (subjective, independent of image analysis) 
 
 
 
 
New - Chronology 
ENSO & Peru Margin Sediments 
Palaeo – ENSO:  Previous work 
What is the problem? 
ENSO reduced or absent between 15ka and 6ka 
Sandweiss et al. 1996a & b;  between 5800 and 3200-2800 Cal yr BP, El 
Nino events less frequent that today, and for several millennia prior to 
5800 yr El Nino “absent or very different from today” (archaeological, 
molluscs) (8oS – 18oS) (Geology, Nature) 
Koutavas et al., 2002;  30,000 yr low-resolution magnesium-calcium ratio 
in foraminifera near Galapagos Is compared with west Pacific alkenone 
SST record show “mid-Holocene cooling” suggestive of La Nina 
conditions; late mid and early Holocene, and 14-15 ka (Bølling) similar to 
today (Science) 
Moy et al., 2002; Continuous 12,000 yr record from Lake Pallcacocha; not 
quite ENSO interannual resolution, but variance in red colour intensity 
record suggests low variance in the Early Holocene; either ENSO starts 
after 7,000 yr BP, or is weak in the Early Holocene  (2o-3oS) (Nature) 
Gagan et al. 2004; Onset of ENSO periodicities at ~5000 yrBP, with a 
sudden increase in ENSO magnitude at ~ 3000 yrBP and maximum ~2300-
1700 yr BP; precipitation response to El Nino temp anomalies “subdued” 
in mid Holocene; western-central Pacific; attributed to mean southward 
shift in the ITCZ [Quaternary International] 
 
 
 
ENSO & Peru Margin Sediments 
Eastern Pacific Holocene Record 
ENSO & Peru Margin Sediments 
Tropical Pacific SST Gradient 
From Koutavas et al. 2002 (their Fig. 3) 
ENSO & Peru Margin Sediments 
from Rein et al. 2005  
(their Fig. 11) 
Rein et al. 2005;  
SST ~ 2oC warmer 
than today between 
10,300 and 8,900 yr 
BP; El Nino 
declining over last 
800 yrs; Alkenone 
SST data; primary 
productivity index 
and terrestrial proxy 
for ENSO flooding 
since LGM; 
[Paleoceanography] 
ENSO & Peru Margin Sediments 
Summary  
♦ Modern ENSO pattern continuous since 
post mid Holocene 
♦ Tropical Pacific SST gradient greater in 
middle Holocene than currently 
♦ Records not consistent for Early 
Holocene or LGIT  
♦ Gaps? 
What happens to the currents and 
sediment  in El Nino heartland during 
these periods? 
 
 
 
 
 
 
ENSO & Peru Margin Sediments 
“New” data   
Recalibrated and regionally extensive 
radiocarbon data 
Regionally consistent pattern of 
sediment accumulation 
High-resolution geochemical and 
image data 
ENSO & Peru Margin Sediments 
Location & 
Material 
ENSO & Peru Margin Sediments 
Regional Marine Reservoir Correction 
Ortleib et al.,  2010:  [Quaternary Research] 
On basis of co-located terrestrial (charcoal) and marine 
(shells) radiocarbon along Chilean coast determined extensive 
variability in regional marine reservoir effect DR 
2s range between 1000 – 500 yr but three-fold subdivision of 
Holocene: 
» 511± 278 yr (10,500-6,800 yr BP) 
» 226± 98 yr (5,200-1,000 yr BP)  
» 250-350 yr (<1000 yr BP) 
Inferred significant changes in ocean currents particularly 
with old carbon source (i.e. upwelling) reduced after 5000 yrs 
(i.e. long-term El Nino-like conditions increasing after 5500 – 
5300 yr BP)  
We have recalibrated all previously published 
radiocarbon ages using DR : 
 » 511± 278 yr  (for > 5000 yr) 
 » 279 53 (for 0-5000 yr) 
 and the Marine09.14C Reimer et al. (2009) Radiocarbon 51 
 
ENSO & Peru Margin Sediments 
Holocene Age-Depth  
ENSO & Peru Margin Sediments 
Regional Pattern of Sedimentation  
100-
150 
cm/ka 
~2250 yrBP 
20-50 
cm/ka 
4-10 
cm/ka 
90-120 
cm/ka 
~4400 yrBP 
~8150 yrBP 
~15000 yrBP 
(~250 
cm/ka) 
(~10-50 
cm/ka) 
ENSO & Peru Margin Sediments 
Changes in Sedimentation Rate? 
The Record: 
● Sediment bypass 
● Deposition and Erosion 
● Changes to volume of sediment delivery 
Mechanisms 
● Ocean current velocity/direction (strong 
upwelling in middle Holocene) 
● Productivity/Nutrient load 
● Terrestrial input 
ENSO & Peru Margin Sediments 
XRF Scanning Data  
Avaatech XRF Core Scanner 
106KL (Marum Bremen);  
1229E, 1227A (College Station) 
Nineteen elements @ 2 mm interval 
- Al  Si  P  S  Cl  K  Ca  Ti  Mn  Fe  Rh 
- Cu  Zn  Br  Rb  Sr  Zr  Mo  Pb 
ENSO & Peru Margin Sediments 
1227A 1229E 
Si:Al, Mo:Al, Ca Trends 
106KL 
~2250 yrBP ~4400 yrBP ~8150 yrBP 
~15000 yrBP 
ENSO & Peru Margin Sediments 
Statistics 
106KL  late Holocene 1229E  late Holocene 
silicon calcium Terrestrial group 
ENSO & Peru Margin Sediments 
Statistics (cont) 
106KL  early Holocene 1229E  early Holocene 
silicon calcium Terrestrial group 
ENSO & Peru Margin Sediments 
Stratigraphy 
 
ENSO & Peru Margin Sediments 
The Cores – Late Holocene 
106KL 
1229E 
to
p
 
to
p
 
ENSO & Peru Margin Sediments 
The Cores – Middle Holocene 
106KL 
1229E 
to
p
 
to
p
 
ENSO & Peru Margin Sediments 
The Cores – Early Holocene 
106KL 
1229E 
to
p
 
to
p
 
ENSO & Peru Margin Sediments 
Summary 
Sedimentary layers of at least four types 
Middle Holocene time of disruption – 
evidence of both bioturbation (slow 
sedimentation & oxygenated bottom 
waters?) and slumping (increased current 
velocity) 
Early and Late Holocene similar in terms of 
deposition and preservation of laminae 
LGIT – yet to be resolved; geochemically 
different, extensive slumping, high 
sedimentation rates, interannual laminations 
ENSO & Peru Margin Sediments 
 
END 
Acknowledgements 
♦ K41009: Nuclear and isotopic studies of the El 
Niño phenomenon in the ocean   
♦ AINSE (grant numbers 02/169, 04/139, 05/151) 
 
 
ENSO & Peru Margin Sediments 
Grain Size 
Grain size 
ENSO & Peru Margin Sediments 
Stokes Settling 
2 yr 
3 m 
18 days 
20 m 
ENSO & Peru Margin Sediments 
 
Oxygen Minimum Zone 
Red:  Extreme El Niño 
Yellow: Normal 
J. Helly, Scripps Supercomputer Center 
Pacific Ocean 
Peru Trench 
Andes 
Galapagos Islands 
ENSO & Peru Margin Sediments 
Geochemical Results 
El Nino  “Normal” 
If temperature ~ 1OC warmer 
If salinity ~ 0.5 PPT fresher 
Decreased calcite production 
Decreased TOC 
Assume pale = 100% marine with 
d13C -21.5‰ and typical C3 with -
27‰, then shift of -0.46‰ ~ 8% 
terrestrial mixing 
SST Precipitation 
Ocean  
“productivity” 
Terrestrial  
vegetation 
Darker layers are: 
•Warmer 
•Wetter 
•Reduced  
          “productivity” 
New - Geochemistry 
ENSO & Peru Margin Sediments 
 
= Dark bands        = Light bands 
Stress = 0.15 p-F = 3.21, P < 0.01  
Results of non-parametric multivariate comparison of dark vs light bands. Data are Normalised 
and Euclidean distance coefficient was used. nMDS is used to graphically represent the 
comparison and  NP-MANOVA was used to test the hypothesis.  
New - Geochemistry 
ENSO & Peru Margin Sediments 
Modern ENSO Time Series 
normalised power 
Trenberth & Hurrell (1993) 
Zhang et al. (1997) 
Urban et al. (2000) 
 
New – Times Series 
ENSO & Peru Margin Sediments 
Time Series 
Red colour intensity of interannual ENSO (band pass filter to extract 2-7.5 yr 
variance –                            ) 
Amplitude modulation of interannual ENSO –  
Layer trends (events per 100 yr) 
aqua curve 
green curve 
Three Sets of  Spectral Analyses: 
(Evolving spectrograms of  normally-distributed data using Blackman-Tukey FFT with 
  Hanning window ) 
ENSO & Peru Margin Sediments 
Late Holocene Time Series  1229E 
ENSO band variance amplitude modulation 
LIA 
Medieval  
Warm 
Dark Ages 
100-200 yr 
normalised power 
ENSO & Peru Margin Sediments 
Frequency ~ 220 yr (Suess?) 
Inverse correlation between events per 100 years and thickness per 10 cms (i.e. if more layers  per time, 
they are thinner  ~constant sedimentation rate) 
~ inverse correlation between thickness per 10 cm and % dark per couplet (i.e. where there are more 
events per 100 yr, ENSO (dark) part of the couplet is dominant) 
Recent past compaction articfact? 
Industrial LIA Medieval Warm Middle Ages Cold 
422 layers 
New – Layer Trends 
ENSO & Peru Margin Sediments 
Early Deglaciation Time Series  1227B 
ENSO & Peru Margin Sediments 
Evolving spectrum ENSO variance Evolving spectrum amplitude oscillation 
Deglaciation Time Series  1227B 
~6.4 yr 
~11.0 yr 
~5.7 yr 
Allerod 
(warm) 
OD 
(cold) 
(warm) 
H1 
(cold) 
~54 yr 
~30 yr 
200- 
70 yr 


Regional controls on holocene sedminentation patterns along the Peru contonental margin; long term implications for El Niño-Southern Oscillation

http://apo.ansto.gov.au/dspace/bitstream/10238/9627/1/INV003%20SKILBECK%20%28Presentation%29.pdf

Regional controls on holocene sedminentation patterns along the Peru contonental margin; long term implications for El Niño-Southern Oscillation

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