Post on 22-Mar-2016
description
A TEMPERATURE REGULATED ORGANIC CARBON CAPACITOR
ON EARTH’S SURFACE
Gerald R. DickensRice University
(and Nemanja Komar, Benjamin Slotnick, Christopher Hollis, Richard Zeebe )
Glomar Challenger
Lower PaleogeneDSDP Site 577
[Dickens & Backman, News. Strat., 2013]
[ Hollis et al., 2004 ]
~100m
Mead Stream, New Zealand
Late Paleocene-Early Eocene
Carbon Isotope Records
[Slotnick et al., Journal of Geology, 2012]
PETM at Mead Stream, New Zealand
[Nicolo et al., Paleoceanography, 2010]
Ocean
Atmosphere BiosphereVolcanoes
dVol = -5.0FVol = 0.072
Weathering
dWeat = -22FWeat = 0.12
Rivers
dRiv = 0.0FRiv = 0.408
Inputs
dIn = -5.0FIn = 0.60
Organics
dOrg = -28.5 = 0.13
Carbonate
= 1.5 = 0.47
Outputs
dOut = -5.0FOut = 0.60
FOrg
dCarbFCarb
dEx = -1.45MEx = 56000
dBio = -28.5MBio = 3400
dAtm = -7MAtm = 1400
dOc = 0.5MOc = 51200
Anthropogenic
dAnt = -30.0FAnt = 8.00
A Carbon Input to the Phanerozoic Carbon Cycle
[adapted from Kump & Arthur, Chem. Geol., 1999 ]
Exo
geni
c C
ompo
sitio
n, d
Ex (
‰) 0
-1
-2
-3
-4 100
1,000
10,000
100,000
0 100 200 300Time (kyr)
0 100 200 300Time (kyr)
Car
bon
Inje
ctio
n, M
Ex (
Gt)
Theoretical Carbon Inputs forRapid, Global Negative d13C Excursions
dAdd = -60 ‰
dAdd = -5 ‰
dAdd = -22 ‰
dAdd = -5 ‰
dAdd = -60 ‰
dAdd = -22 ‰
[ Dickens, Geol. Soc. London, 2001 ]
IPCC
Ken Caldeira
Dickens, Bull. Soc. Geol. France, 2000
Zachos et al., Proc ODP Inti. Repts., 208, 2004
PETM at Walvis Ridge
[ Hollis et al., 2004 ]
Predicted Change in Pacific Dissolved Oxygen by AD 2680
[ Matear & Hirst, Global Biogeochemical Cycles, 2003 ]
(mmol/km3)
[Nicolo et al., Paleoceanography, 2010]
PETM at Mead Stream
[ IPCC, 2007 ]
[Slotnick et al., Journal of Geology, 2012]
Figure 7.3: Global Carbon Cycle
[ IPCC, 2007 ]
A Simple Capacitor for Global Carbon Isotope Excursions
Seafloor Methane (Peat/Permafrost)
[ adapted from Dickens, EPSL, 2003 ]
[Dickens and Backman, News. Strat., 2013 ]
Carbon Storage (long-term)
Carbon Release(long-term & short-term)
Carbon Isotope Records at DSDP Site 577
Sulfur Isotopes (Correct Age)
[original sulfur data from Paytan et al., 1996]
Gas Hydrate, AOM and Sulfur Cycling
[ Snyder et al., Deep-Sea Res., 2007 ]
12CH4 + SO42- --->
H12CO3- + HS- + H2O
2CH2O ---> 12CH4 + 13CO2
Alkalinity (HCO3-)
SO42-
Solid S
[ Snyder et al., Deep-Sea Res., 2007 ]
Welcome to the Dark Side: Lee’s Paleogene Machine
[Dickens, Climate of Past, 2011]
[Komar et al., Paleoceanography, in press ]
Long-termModel Results
[Hancock et al., 2007 ]
DSDP Site 259(Indian Ocean)
[Expedition 346 Scientists, 2014]
Back to the Future?
Absolutely. The Eocene is forcingfuture science forward.