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

Transcrição

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
Neumayer
Antarctic
Peninsula
EPICA-DML,
2774m, >250 ka
Kohnen
Weddell Sea
JARE
3029m, >700 ka
Dome F
Dyer Pl.
B15 Berkner Is.
South Pole
Siple St.
China, planned
Dome A
Russia, F, US
3700m, 420 ka
Vostok
Byrd
EPICA-DC,
Siple D.
3270m, 800 ka
Dome C
Deep ice
cores in
Antarctica
Law Dome
Taylor D.
Ross Sea
I, F, D, UK
Talos D.
layout: w. rack, h. oerter, AWI
2
European Project for Ice Coring in Antarctica (EPICA)
Dronning-Maud-Land
Dome C:
68°S
Neumayer
Ekströmisen
W
SANAE IV
70°S
a
rfly
H.
500
1000
1500
200
0
25
00
Troll
f.
up
r
rd
We
72°S
3000
ge
ne
ve
.S
ris
en
74°S
DM
L
on
tf.
05
Kohnen
efr
Kohnen
76°S
Amundsenisen
He
Brunt
Ice Shelf
70°S
.
Kottas
Camp
Wasa
72°S
U
he
itsc
Kir
wa
nv
R
Riiser- Larsen- I
se
n
17. Jan. 2006
2774 m
> 250 ka
Novolazerevskaja
S
DML:
Mario Zuchelli
SANAE III
ea
ed
10°E
Jutulstraumen
ll
de
0°
im
21. Dec. 2004
3272m
ca. 800 ka
( 2x Vostok)
10° W
00
2000
1500
00
10
0
50
Traverse routes:
Ice shelf
25
Inland ice, grounded ice
U.K.
Sweden
00
Sea
30
74°S
EPICA comprises two ice cores:
Halley
km
500
0
Dome C
30°W
20°W
10° W
0°
10°E
(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;
10 European nations working together:
ice 2782 ±10m, -44.6 °C, 64 kg m-2 a-1)
Belgium, Denmark, France, Germany, Italy, The Netherlands, Norway, Sweden,
Switzerland, United Kingdom
2000
contour line
Germany
grounding line
Norway
Funding by the European Commission and by national contributions. For Germany AWI & DFG
3
Accumulation
Antarctica
Summit
Accumulation
Inland ice /
Ice sheet
Melting
Ablation
Iceberg
calving
Iceberg
calving
max: 4775 m
Greenland
Ice thickness
typical for
mean: 2078 m
Grounding line
Ice shelf
Rock
subglacial melting
500 - 1000 km
Ablation
ca. 2000 km
Ocean
100 - 700 km
grafic: AWI / hans oerter, 2004
Equilibrium line
mean: 3080 m
mean: 1667 m
Ice thickness
Schematic Cross Section Through an Ice Sheet
Accumulation
4
foto: hans oerter, 2006
The drill trench
5
10 mm
33 x 33 mm
15 mm
54 mm
24 mm
Thin sections
CFA
18
2
δ O, δ H
10Be
44 mm
55 mm
Archive
Gases, dust
CO2, CH4, N2O
& isotopes
98mm
Cutting scheme for EPICA ice cores
6
-38
δ18Ocorr [°/ ]
°°
a)
MIS1
-43
LGM
-48
EDML
MIS4
MIS3
MIS5.5
-36
-40
-44
-48
-52
-330
Dome F
-53
-58
δDcorr [°/°°]
-410
-32
-450
DO1
δ18O [°/ ]
°°
b)
-370
EDC
-63
Tsurf [°C]
-36
-40
1112 14 16
34 6 7 810
1517
5
13
18
2
9
19
20 21
22
23 24 25
NGRIP
-44
-48
-490
synchronized by
Methane
concentrations
-530
1000
EDML
c)
100
25-50
0
EDC
50000
100000
10
dust [ppb]
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.
150000
EDML age [yrs BP]
EPICA Community Members: nature 444, 9 November 2006. doi:10.038/nature06301
The EPICA EDML-ice core
7
Each Antarctic
Isotope Maximum
(AIM) in the EDMLice 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)
AMOC: Atlantic
Meridional Overturning
Circulation
Bipolar seesaw depending on AMOC
AIM
D/O
Age on new NGRIP time scale (kyrs BP)
Source: EPICA community members: Nature ,Vol. 444 , November 9, 2006)
Comparison Antarctica (EDML) - Greenland (NGRIP)
8
16
6 810 12
19 20
14
17
4
11
7
5
13 15 18
3
9
4.
1
18.1
2
23 24
21 22
25
-35
-40
M IS 5.5
TI
-5
M IS 4
A C R M IS
2
M IS
7.5
M IS
M IS 7.3
7.1
M IS 6
M IS 5.3
M IS 5.2
M IS
9.3
50
M IS
7.4
°C
M IS
11.1
M IS
7.2
150
200
0
M IS 11.3
0
M IS
14.3
M IS 13.3
M IS
12.3
M IS
M IS
12.4
12.2
-5
TV I
M IS
13.1
M IS
13.2
-10
500
A ge (ky BP)
M IS
M IS 14.2 14.4
550
300
350
400
M IS
15.5
T V II
M IS
16.4
M IS
16.2
M IS M IS
15.2 15.4
600
M IS
16.3
-5
M IS
17.3
A ge (ky BP)
650
700
Age (ky B.P.)
-10
450
M IS
15.3
M IS
15.1
TV
M IS 11.2
M IS 9.2
250
-45
M IS 5.4 A ge (ky BP)
100
T IV
T III
M IS 8
T II
M IS
5.1
M IS 3
-10
Antarctic temperature
change (°C)
in ‰
0
M IS 10
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 superimposed 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 temperature 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.
N orth
G R IP
North GRIP δ18O (‰)
D O events
01
5
d18O
T V III
M IS
18.2
change (°C)
Strength of
interglacials
depending on
whether obliquity
and precession
peak in phase or
not
change (°C)
AIMs appear also in
earlier glacials
°C
M IS
18.3
M IS
19.3
750
T IX
800
Jouzel, J. et al.:, Science 317, 793-796 (2007)
Dome C temperature anomaly over 810 ky
9
Antarctic ice core records: Vostok and EPICA CO2, CH4 and DD
at present 375
CO2 (ppmv)
300
Vostok (black) and Dome C (blue) data
270
240
210
180
EPICA Dome C data
DD ice (‰)
Warm
-390
Cold
-420
-450
CH4 (ppbv)
vor 1850 AD
Vostok (black) and Dome C (blue) data
700
600
500
400
300
0
today
100
200
300
400
Age / kyr BP
500
600
700
800
EPICA data are plotted on EDC2, Vostok data on GT4 timescale
Petit et al., 1999 (Vostok), Siegenthaler et al., 2005 (Dome C - CO2),
Spahni et al., 2005 (Dome C - CH4), EPICA community members, 2004 (DD)
10
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.
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).
Summary
11

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

Transcrição

Documentos relacionados

Apresentação do PowerPoint

Ice Crystals Conditions

McDonald`s Junior Open 2004-2016: Siegerlisten

SRK-3040S