Image:Epica-vostok-grip-140kyr.png

William M. Connolley on the English Wikipedia project has granted permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License." Subject to disclaimers.

• Suomi: Viime jääkauden lämpötilaa kuvaava happi-isotooppipitoisuuskäyrä Grönlannissa: punainen ja Antarktiksella kahdesta kohtaa: musta ja sininen.

• English: From the Vostok and EPICA (Antarctica) and NGRIP (Greenland) ice cores: d-o-18, last 140kyr.

Horizontal axis: time before 1950 (I think). Vertical axis: delta-O-18.

See-also: en:Image:Epica-vostok-grip-ngrip-o18.png.

Note that d-O-18 is a proxy for temperature: more negative is colder; the period from 20 to 10 kyr shows the rise in temperature at the end of the last ice age. Note the Dansgaard-Oeschger events visible in the NGRIP core but barely, if at all, in the Antarctic cores. The period around 120 kyr is the previous interglacial; before that (140 kyr) is the previous glacial.

Updated version of en:Image:Epica-vostok-40kyr.png including NGRIP, from:

NGRIP: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/ngrip/isotopes/ngrip-d18o-50yr.txt (ss09sea timescale)

EPICA: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/epica_domec/edc_dd.txt (EDC2 timescale)

Vostok: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/vostok/deutnat.txt (GT4 timescale)

Code:

a=readfromfile('edc_dd1.txt',col=6,ign=1)

b=readfromfile('vostok_deutnat1.txt',ign=1,col=4)

c=readfromfile('grip.txt',ign=10,col=2)

!p.multi=[0,1,2]

ep=reform(a(5,*))
vo=reform(b(2,*))
gr=reform(c(1,*))*10

plot,a(4,*),ep,title='delta-o18 vs age',/xs,xr=[0,120000.],ymarg=[2,5],yr=makerange([ep,vo,gr]),th=1
oplot,col=3,b(1,*),vo,th=1
oplot,col=2,c(0,*),gr,th=1
oplot,a(4,*),ep,th=1
add_key,/rig,['EPICA (Antarctic)','Vostok (Antarctic)','GRIP (Greenland)'],[!p.color,3,2],th=3,/top