a.moreno (1,2), h. stoll (3), i. cacho (4), montserrat jiménez- sánchez (3), carlos sancho (5),...
TRANSCRIPT
A.Moreno (1,2), H. Stoll (3), I. Cacho (4), Montserrat Jiménez-Sánchez (3), Carlos Sancho (5), Ánchel Belmonte (5), R. L.
Edwards (1), E. Ito (1), B. L. Valero-Garcés (2)
(1) Limnological Research Center, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 (USA)
(2) Pyrenean Institute of Ecology - CSIC, Apdo. 202, 50080 Zaragoza, (Spain), (3) Departamento de Geologia, Universidad de Oviedo, C/ Arias de Velasco, s/n 33005 Oviedo (Spain), (4) University of Barcelona, C/ Marti i Franquès s/nº, 28080 Barcelona (Spain), (5) Departamento de Ciencias de la Tierra, Facultad de Ciencias. Universidad de Zaragoza (Spain),
Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record
Outline
Speleothems as exceptional paleoclimate archives
Orbital scale
Last deglaciation main trends
Early Holocene abrupt changes
Study sites in the north of the Iberian Peninsula
Main questions
Conclusions
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
Some preliminary results…
Speleothems as exceptional paleoclimate archives
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
Advantages
- Absolute dating by using the U-Th desintegration series (0-500 kyrs)- High precipitation rate (banding) –abrupt/rapid climate changes- Good records of temperature and precipitation (stable isotopes, trace metals, growth rates…)
Disadvantages
- Only in karstic systems- System monitoring is required (lot of time and money….) - Presence of hiatus in dry or cold climates
Fairchild et al., 2006
Speleothems as exceptional paleoclimate archives
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
Speleothems as exceptional paleoclimate archives
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
2 initial assumptions:- Closed system to U and Th- Initial 230Th = 0 (“pure” samples, with low detrital)
Some sources of errors:- Low U content (depends on the type of limestone)- High 232Th (high 230Th initial)- Post-precipitation effects
18O
Diagenetic processes (evaluated by petrography to discard re-crystallization)
Non-equilibrium fractionation (evaluated by 13C vs 18O correlation, replication or Hendy test)
18O of rainfall
Cave Tª (seasonally stable, long-term variations can modulate the signal)
Other fractionation (eg. evaporation of water in the soil or vadose zone)
Air temperature variations
Variability in the precipitation sources
Amount of precipitation
0.34‰/ºC
NAO; glacial vs interglacial
13C13C values of the carbonate bedrock (fixed values)
13C values of the soil CO2
Soil processes and residence time
Type of vegetation overlying the cave (C3 vs C4)
Speleothems as exceptional paleoclimate archives
Mg/Ca, Sr/Ca, Ba/Ca
Vegetation cover overlying the cave
Marine aerosols – distance to the coast
Prior calcite precipitation (link to dry/wet climates)
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
Study sites in the north of the Iberian Peninsula
Cueva de las Güixas
Cueva 5 de Agosto
Sima de Estebán Felipe
Cueva de Molinos
Zonas calcáreas
CAVECAL-CICYT: Cambios climáticos rápidos en la Península Ibérica basados en calibración de indicadores, series instrumentales largas y análisis de alta resolución de registros en espeleotemas.DGA-LaCaixa: Formaciones de espeleotemas en Aragón: una innovadora aproximación a la reconstrucción del clima de los últimos milenios.
El Pindal and Calabrez caves
PathwayOld fluvial channel
EL PINDAL
Old alluvial deposits
Block accumulations
Mud depositsFlowstone
Complex
SpeleothemsFluviokarstic and gravity features
Gours
Dripstone
Jiménez-Sánchez et al., 2002
non-dolomitic limestones of the Carboniferous Barcaliente Formation
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
R2 = 0.85
- +
5 de Agosto
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
First stalagmites dated from the Spanish Pyrenees.
High altitude cave (1664 m) Monitoring in progress
(temperature, rainfall, dripwaters)
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
Main questions
1) Temporal and spatial reconstruction of main abrupt changes in the Northern Iberian Peninsula during the Pleistocene and Holocene
2) Interpretation of main mechanisms of abrupt climate change in the past, including phenomena affecting the most recent millennia (NAO, solar variability…)
3) Response of terrestrial ecosystems (hydrology, vegetation) to abrupt climate changes at different timescales (orbital, millennial, decadal)
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
At an orbital-scale
Espeleothems from 5 de Agosto Cave (Central Pyrenees) only growth during short periods associated to interglacials: OIS 1, OIS 7, OIS 9, OIS 11. Surprisingly, there is no sample (after dating 16 stalagmites) growing during OIS 5
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
18O 13C MAX MIN MAX MIN 5Agosto -1 Estadio 11 -5,62 -6,79 1,70 -1,3 5 Agosto-10 Holoceno -5,74 -6,92 -1,41 -4,5 5 Agosto-14 Estadio 7 -5,9 -6,93 4,13 1,55
Isotopes18O values very similar in the three interglacials; 13C has higher variability (particularly, OIS 7)
Identify the growth periods as the warmer and wetter intervals Compare duration and characteristics of the last interglacials Look for an “analogous” for the Holocene (OIS 5??, OIS 11?)
At an orbital-scale
During last deglaciation
CANDELA
CAN sample covers from 25 to 8 kyrs ago with an interruption during the Mystery Interval (Denton, 2005), a particular time period characterized by an increase in sea level but colder temperatures in Greenland and North Atlantic than during the LGM.
We would expect a very cold, and probably dry, scenario for southern Europe.
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
H1YD IAC
P
ODPB LGM HE2
10.39.28.27.4
7000 9000 11000 13000 15000 17000 19000 21000 23000 25000
-48
-44
-40
-36
7000 9000 11000 13000 15000 17000 19000 21000 23000 25000
0
-2
-4
-6
-8
-10
-12
-2
-3
-4
-5
-613C
(‰
)
18O
(‰
)18
O (
‰)
NG
RIP
(G
CC
05)
(Ra
ssm
uss
en
et
al.
QS
R 2
00
8)Age (years BP)
CANDELAMARIA
HIATUS
HIATUS
Mystery interval
GI-1 HOLOCENE GS-1 GS-2bGS-2aGi-2 GS-2C
DrierNAO +
WetterNAO -
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
During last deglaciation
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
H1YD IAC
P
ODPB LGM HE2
18O
(‰
) N
GR
IP (
GC
C05
)(R
ass
mu
sse
n e
t a
l. Q
SR
20
08
)
MARIA
GI-1 HOLOCENE GS-1 GS-2bGS-2aGi-2 GS-2C
13C
(‰
)
7000 9000 11000 13000 15000 17000 19000 21000 23000 25000
-48
-44
-40
-36
7000 9000 11000 13000 15000 17000 19000 21000 23000 25000
0.006
0.005
0.004
0.003
0.002
0.001
0
-2
-4
-6
-8
-10
-12
10.39.28.27.4
Ba/
Ca
CANDELA
Wetter
Drier
During last deglaciation
7.4 8.3 9.4 10.2 11.2
7000 7500 8000 8500 9000 9500 10000 10500 11000 11500 12000
-4
-6
-8
-10
-12
-3
-3.5
-4
-4.5
-5
-5.5
-8
-4
0
4
8
7000 7500 8000 8500 9000 9500 10000 10500 11000 11500 12000
13C
(‰
)
18O
(‰
)H
SG
(de
tren
ded)
Bond et al., 2001
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
During the Early Holocene
COLD
WARM
WET
DRY
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
109.99.2
10.3
9.4 9.6
18O
(‰
)
18O
(‰
)
MARÍA(this study)
18O
(‰
)
18O
(‰
)Dongge Cave(Dykoski et al., 2005)
NGRIP
Dongshiya Cave(Cai et al., 2008)
PB10.910.4109.39.1
8800 9200 9600 10000 10400 10800 11200 11600 12000
-3
-3.5
-4
-4.5
-5
-5.5
-7
-7.5
-8
-8.5
-9
-9.5
-9
-10
-11
-12
-40
-38
-36
-34
During the Early Holocene
A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula
Conclusions
Speleothem records from Northern Spain are excellent paleoclimate records of past hydrological variability that need to be studied with further detail
Growing periods in the Central Pyrenees are related to some interglacials pointing to the most humid and the warmest intervals for the last 400 kyrs.
The driest period for the last 25 kyrs is the “mystery interval” as indicated by the hiatus
Paleohydrological and vegetational response to the abrupt changes during deglaciation (HE1, B/A, oldest and older Dryas, IACP) and Early Holocene abrupt changes
NAO-type mechanism behind abrupt climate changes recorded in the Iberian Peninsula?