Two EPICA ice cores revealing 800,000 years of climate history: An overview. Hans Oerter & EPICA team

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

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

JARE

3029m, >700 ka

Russia, F, US

3700m, 420 ka

China, ^planned

EPICA-DC,

3270m, 800 ka

I, F, D, UK Weddell Sea

Ross Sea Antarctic

Peninsula

Deep ice cores in Antarctica

Neumayer

Mario Zuchelli

10° W 0° 10°E

10° W 0° 10°E

20°W 30°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 1500 2000

2500 3000

Neumayer

SANAE IV

Troll

Wasa

Kottas

Camp DML05

Amundsenisen

Wegenerisen

Brunt Ice Shelf

Riiser- Isen

Larsen-

Heimefrontf.

Kirwanv.

H.U.Sverdrupf.

Dronning-Maud-Land

Ritscherflya

Weddell Sea^Ekström-_isen

Jutulstraumen

0 km 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

a

) Dronning Maud Land (DML, Kohnen) (75 ° 0.10' S, 0° 4.07' E, 2892 m;

ice 2782 ±10m, -44.6 °C, 64 kg m

a

)

Dome C:

21. Dec. 2004 3272m ca. 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 for

Antarctica

Summit

Equilibrium line mean: 2078 m max: 4775 m

100 - 700 km ca. 2000 km

500 - 1000 km

Iceberg calving

Ocean

Inland ice / Ice sheet

Ice shelf

subglacial melting

Accumulation Ice thickness

Ablation Melting

Ablation Accumulation

Schematic Cross Section Through an Ice Sheet

mean: 1667 m mean: 3080 m Grounding line

Greenland

Accumulation

Iceberg calving

Ice thickness

Rock

The drill trench

Cutting scheme for EPICA ice cores

33 x 33 mm

15 mm 24 mm

54 mm 44 mm

55 mm

98mm

foto: hans oerter, 2006

10 mm Thin sections

CFA δ ¹⁸ O, δ ² H

10 Be Archive

Gases, dust

CO 2 , CH 4 , N 2 O

& 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

δ

O

[°/ ] °°

EDML age [yrs BP]

du st [p pb]

MIS1

EDC EDML

δ D

[°/ °° ] T

[° C]

DO1

2 3456789101112 13

141516 1718

1920 21

22 2324 25

Dome F EDC

δ

O [°/ °° ]

NGRIP

MIS3 MIS4

MIS5.5 LGM

25-50

synchronized by Methane concentrations

Antarctic stable isotope records show synchronous millennial variations during the last glacial, whereas rapid variations are encountered in Greenland.

a) EDML δ¹⁸O record (purple, 0.5-m resolution; grey, 15-m running

mean) after sea level and

upstream correctionover the past 150 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 that

EDML and EDC are plotted on the new common

EDC3 timescale while Dome F is plotted on its individual

timescale. The temperature axis on the right side indicates

approximate surface

temperatures at EDML as derived from the

spatial δ¹⁸O/temperature gradient.

b) δ¹⁸O record of

the NGRIP ice core (grey).

c) Mineral dust

records of the EDML (red) and EDC (pink) ice cores at 1,000-yr resolution; these dust records were 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

100 50

-10 -5

0

450 400

350 300

250 200

150

-45 -40 -35

-10 -5

0

800 750

700 650

600 550

500

D O events

2 3 4

4.1 5

6 8 7

9 10

1112 13

1415 16

17

1818.1

19 20 21 22 23 24 25

N orth G R IP

A C R

T_I

T_II

T_III T_IV T_V

T_{V I}

T_{V II} T_{V III} T_IX

d ¹⁸

O in ‰

°C

°C

°C A ge (ky BP)

A ge (ky BP)

A ge (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 IS 19.3 M IS 5.5

M IS 5.4 M IS

5.1

M IS 5.2 M IS 5.3

M IS M IS 7.5

M IS 7.3 7.1

M IS 7.2

M IS 7.4

M IS 9.3

M IS 9.2

M IS 11.3 M 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 13.3

M IS 14.3

M IS 14.4

M IS

15.1 M IS

15.5 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 0 1

Age (ky B.P.)

Antar ctic temperatur e change (°C) Antar ctic temperatur e change (°C) Antar ctic temperatur e change (°C) North GRIP δ

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 and

AIM 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 CO

, CH

and D D

Petit et al., 1999 (Vostok), Siegenthaler et al., 2005 (Dome C - CO₂), Spahni et al., 2005 (Dome C - CH₄), EPICA community members, 2004 (DD)

180 210 240 270 300

CO

(ppmv)

-450 -420 -390

Cold Warm

D D ice (‰)

300 400 500 600 700

0 200 400 600 800

Age / kyr BP CH

(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 (CO 2 , CH 4 , N 2 O) are now at their highest concentrations of the past 650,000 years.

CO 2 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: hans oerter, 2008

Summary