two epica ice cores revealing 800,000 years of climate ... · 23. internationale polartagung der...

23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008

Two EPICA ice cores revealing 800,000 years of climate history:

An overview.

Hans Oerter & EPICA team

Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, Bremerhaven

23. Internationale Polartagung der Deutschen Gesellschaft für Polarforschung, Münster, 10.-14. März 2008 2

Kohnen

Dome C

Vostok

Dome A

Dome F

Law Dome

Talos D.

Taylor D.

Siple D.

Byrd

Siple St.

Dyer Pl.B15 Berkner Is.

South Pole

layout: w. rack, h. oerter, AWI

EPICA-DML,2774m, >250 ka

JARE3029m, >700 ka

Russia, F, US3700m, 420 ka

China, planned

EPICA-DC,3270m, 800 ka

I, F, D, UK

Weddell Sea

Ross Sea

AntarcticPeninsula

Deep ice cores in

Antarctica

Neumayer

Mario Zuchelli

10° W 0° 10°E

10° W 0° 10°E20°W30°W

74°S

72°S

70°S

68°S

74°S

72°S

70°S

76°S

3000

2500

2000

1500 1000

500

500

1000

1

500

200

0

2500

3000

Neumayer

SANAE IV

Troll

WasaKottasCamp DML05

Amundsenisen

Wegenerisen

BruntIce Shelf

Riise

r-

Isen

Lars

en-

Heim

efron

tf.

Kirwa

nv.H.U.Sver

drupf.

Dronning-Maud-Land

Ritscherflya

Weddell Sea

Ekström-isen

Jutu

lstra

umen

km0 500

SANAE

Hall

III

ey

Novolazerevskaja

Sea Ice shelf Inland ice, grounded ice 2000 contour line grounding line

U.K.Traverse routes: Sweden Germany Norway

Kohnen


EPICA comprises two ice cores:Dome C (75 ° 06.10' S, 123° 23.71‘E, 3233 m;ice 3250 ±25m, -54.5 °C, 25 kg m-2 a-1)Dronning Maud Land (DML, Kohnen)(75 ° 0.10' S, 0° 4.07' E, 2892 m;ice 2782 ±10m, -44.6 °C, 64 kg m-2 a-1)

Dome C:21. Dec. 2004

3272mca. 800 ka

(~2x Vostok)

DML:17. Jan. 2006

2774 m> 250 ka

European Project for Ice Coring in Antarctica (EPICA)

10 European nations working together:

Belgium, Denmark, France, Germany, Italy, The Netherlands, Norway, Sweden, Switzerland, United Kingdom

Funding by the European Commission and by national contributions. For Germany AWI & DFG

Kohnen


typical forAntarctica

Summit

Equi

libriu

m li

ne

mea

n: 2

078

m

max

: 477

5 m

100 - 700 kmca. 2000 km500 - 1000 km

Icebergcalving

Ocean

Inland ice / Ice sheet

Ice shelf

subglacial melting

Accumulation

Ice

thic

knes

s

AblationMelting

Ablation Accumulation

Schematic Cross Section Through an Ice Sheetm

ean:

166

7 m

mea

n: 3

080

m

Gro

undi

ng li

ne

Greenland

Accumulation

Icebergcalving

Ice

thic

knes

s

graf

ic: A

WI /

han

s oe

rter,

200

4

Rock


The drill trench

foto

: han

s oe

rter

, 200

6


Cutting scheme for EPICA ice cores

33 x 33 mm

15 mm 24 mm

54 mm 44 mm55

mm

98mmfoto: hans oerter, 2006

10 m

m

Thin sectionsCFA

δ18O, δ2H10Be

Archive

Gases, dustCO2, CH4, N2O

& isotopes


The EPICA EDML-ice core

EPICA Community Members: nature 444, 9 November 2006. doi:10.038/nature06301

-63

-58

-53

-48

-43

-38

10

100

1000

0 50000 100000 150000

-530

-490

-450

-410

-370

-330-52-48-44-40-36

-48

-44

-40

-36

-32

EDML

δ18O

corr

[ °/°°

]

EDML age [yrs BP]

dust[ppb]

MIS1

EDC

EDML

δ Dcorr

[°/°° ]T

surf[°C

]

DO1

2345678

9101112

1314

1516

1718

1920 21

222324 25

Dome F

EDC

δ18O

[°/°°

]

NGRIP

MIS3MIS4

MIS5.5

LGM

25-50

synchronized by Methane

concentrations

Antarctic stable isotope records show synchronous millennial variations during the last glacial, whereas rapid variations areencountered in Greenland. a) EDML δ18O record (purple, 0.5-m resolution; grey, 15-m runningmean) after sea level and upstream correctionover the past150 kyr. The record shows features similar tothose of the EDC (blue) and the Dome F(pink) isotope records but with more fine structure during MIS3 and MIS4. We note thatEDML and EDC are plotted on the new commonEDC3 timescale while Dome F is plotted on its individual timescale. The temperature axis on the right side indicates approximate surfacetemperatures at EDML as derived from thespatial δ18O/temperature gradient.b) δ18O record ofthe NGRIP ice core (grey).c) Mineral dustrecords of the EDML (red) and EDC (pink) ice cores at 1,000-yr resolution; these dust recordswere used for synchronization of the cores.

a)

b)

c)


Age on new NGRIP time scale (kyrs BP)

Comparison Antarctica (EDML) - Greenland (NGRIP)

Each Antarctic Isotope Maximum (AIM) in the EDML-ice core corresponds to a D/O event in Greenland (NGRIP)

Warming in Antarctica starts in a cold phase (Stadial) of the North, Cooling in a warm phase (Interstadial)

AIM

D/O

Source: EPICA community members: Nature ,Vol. 444 , November 9, 2006)

Bipolar seesaw depending on AMOC

AMOC: Atlantic Meridional Overturning

Circulation


Dome C temperature anomaly over 810 ky

-10

-5

0

5

10050

-10

-5

0

450400350300250200150

-45

-40

-35

-10

-5

0

800750700650600550500

DO events

2 344.156 87

9

101112

131415

1617

1818.1

19 20 21 22 23 24 25North GRIP

ACR

TI

TII

TIII TIVTV

TVI

TVII TVIII TIX

d 18Oin ‰

°C°C

°C

Age (ky BP)

Age (ky BP)

Age (ky BP)

M IS 2

M IS 3

M IS 4

M IS 6

M IS 8

M IS 10

M IS 12.3

M IS 14.2

M IS 16.2 M IS

18.2

M IS19.3

M IS 5.5

M IS 5.4

M IS 5.1

M IS 5.2M IS 5.3

M IS 7.5M IS

7.3M IS 7.1

M IS 7.2

M IS 7.4

M IS 9.3

M IS 9.2

M IS 11.3M IS 11.1

M IS 11.2

M IS 12.2

M IS 12.4

M IS 13.1

M IS 13.2

M IS 13.3M IS 14.3

M IS 14.4

M IS15.1

M IS15.5

M IS 15.3

M IS 15.2

M IS 15.4 M IS

16.3

M IS 16.4

M IS 17.3

M IS 18.3

10

Age (ky B.P.)

Ant

arct

ic t

emp

erat

ure

chan

ge

(°C

)A

ntar

ctic

tem

per

atur

e ch

ang

e (°

C)

Ant

arct

ic t

emp

erat

ure

chan

ge

(°C

)N

ort

h G

RIP

δ18

O (‰

)

Jouzel, J. et al.:, Science 317, 793-796 (2007)

AIMs appear also in earlier glacials

Strength of interglacials depending on whether obliquity and precession peak in phase or not

Back to 140 ky B.P., 100-year mean values are shown, whereas for earlier periods (middle and lower traces), DTs is calculated from 0.55-m raw data; a smooth curve using a 700-year binomial filter is super-imposed on this detailed record.In the upper trace (which is plotted on a more highly resolved time axis), the correspondence is shown between the DO events as recorded in the North Greenland Ice Core Project isotopic record andAIM events recorded in the EDC tem-perature record during the last glacial period and the last deglaciation. We have indicated the successive MIS, and the transitions are labeled from TI to TIX.


Antarctic ice core records: Vostok and EPICA CO2, CH

4 and D

Petit et al., 1999 (Vostok), Siegenthaler et al., 2005 (Dome C - CO2),

Spahni et al., 2005 (Dome C - CH4), EPICA community members, 2004 ( D)

180

210

240

270

300C

O2 (

ppm

v)

-450

-420

-390

Cold

Warm

D ice (

‰)

300

400

500

600

700

0 200 400 600 800Age / kyr BP

CH

4 (

ppbv)

EPICA Dome C data

Vostok (black) and Dome C (blue) data

Vostok (black) and Dome C (blue) data

EPICA data are plotted on EDC2, Vostok data on GT4 timescale

100 300 500 700

today

vor 1850 AD

at present 375

EPICA has produced the definitive ice-core records of climate and evironmental change from Antarctica. EPICA extended the ice-core records back to 800,000 years BP.Greenhouse gases (CO2, CH4, N2O) are now at their highest concentrations of the past 650,000 years.CO2 and Antarctic climate have been tightly coupled over the entire period (providing great constraints on the role of the Southern Ocean).

Each of the rapid Dansgaard-Oeschger events, has an Antarctic counterpart (AIM), strongly supporting the idea that the mechanism was reorganisation of ocean heat transport.


foto

: han

s oe

rter

, 200

8

Summary

two epica ice cores revealing 800,000 years of climate ... · 23. internationale polartagung der...

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