Details

Autor(en) / Beteiligte

• Jochum, K. P.
• Schuessler, J. A.
• Wang, X.‐H.
• Stoll, B.
• Weis, U.
• Müller, W. E. G.
• Haug, G. H.
• Andreae, M. O.
• Froelich, P. N.

Titel

Whole‐Ocean Changes in Silica and Ge/Si Ratios During the Last Deglacial Deduced From Long‐Lived Giant Glass Sponges

Ist Teil von

• Geophysical research letters, 2017-11, Vol.44 (22), p.11,555-11,564

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Silicon is a keystone nutrient in the ocean for understanding climate change because of the importance of Southern Ocean diatoms in taking up CO2 from the surface ocean‐atmosphere system and sequestering carbon into the deep sea. Here we report on silicon isotopes and germanium‐to‐silicon ratios in giant glass spicules of deep‐sea sponge Monorhaphis chuni over the past 17,000 years. In situ measurements of Si isotopes and Ge concentrations show systematic variations from rim to center of the cross sections. When calibrated against seawater concentrations using data from modern spicule rims, sponge data indicate that dissolved silica concentrations in the deep Pacific were ~12% higher during the early deglacial. These deep Pacific Ocean data help to fill an important global gap in paleo‐nutrient records. Either continental sources supplied more silica to the deglacial ocean and/or biogenic silica burial was lower, both of which may have affected atmospheric CO2. Key Points Si isotope and Ge measurements in the deep‐sea sponge Monorhaphis chuni provide an archive of climate change, reaching back to at least 17 ka B.P. Our data suggest that at the onset of the last deglaciation, deep Pacific Ocean dissolved silica was higher and Ge/Si lower than at present