Open AccessEvidence for preindustrial variations in the marine surface water carbonate system from coralline sponges
Author(s) -
Böhm F.,
HaaseSchramm A.,
Eisenhauer A.,
Dullo W.C.,
Joachimski M. M.,
Lehnert H.,
Reitner J.
Publication year - 2002
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2001gc000264
Subject(s) - geology , carbonate , sponge , period (music) , isotopes of carbon , oceanography , dissolved organic carbon , carbon fibers , carbon cycle , surface water , paleontology , earth science , total organic carbon , environmental science , ecology , environmental chemistry , chemistry , ecosystem , physics , materials science , organic chemistry , environmental engineering , composite number , acoustics , composite material , biology
Coralline sponge skeletons are excellent tools for reconstructing the carbon isotope history of dissolved inorganic carbon (DIC) in tropical surface waters. Carbon isotope records from coralline sponges clearly reflect the industrial 12 C increase in atmospheric CO 2 with a precision that permits quantitative interpretations. We find from a set of δ 13 C records of four Caribbean sponge specimens that the isotopic response of surface water DIC to the changing isotopic composition of atmospheric CO 2 varied dynamically during the last century, depending on the rate of atmospheric change. Three of our sponges provide 600 year long δ 13 C records. For the first time, we can reconstruct surface water δ 13 C DIC for the full history of the industrial CO 2 release as well as the preceding preindustrial period back to the beginning of the Little Ice Age. This provides a well‐founded estimate of the anthropogenically uninfluenced, preindustrial background level of surface water 13 C/ 12 C ratios. Our records show small but systematic variations that appear to be linked to the climate fluctuations of the Little Ice Age.