A broad deglacial δ13C minimum event in planktonic foraminiferal records in the Okinawa Trough
A broad deglacial δ13C minimum event in planktonic foraminiferal records in the Okinawa Trough
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DOI：
10.1360/02tb9159
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发表时间：
2002-04
影响因子：
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通讯作者：
L. Tiegang;Liu Zhenxia;M. Hall;Y. Saito;S. Berné;Cang Shuxi;Cheng Zhenbo
中科院分区：
文献类型：
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作者：
L. Tiegang;Liu Zhenxia;M. Hall;Y. Saito;S. Berné;Cang Shuxi;Cheng Zhenbo
赤道太平洋上升流区在全球大气CO2变化中扮演着重要的角色。为探讨热带低纬太平洋表层水冰消期δ 13 C最小值的影响范围，对冲绳海槽中部DGKS 9603孔样的浮游有孔虫N. dutertrei和G.鲁伯。南极有孔虫δ ~（13）C记录显示20 ~ 6cal.kaBP有明显的下降事件，其特征是持续时间长，约为14 ka，振幅漂移为0.4 × 10 - 3。其最小值出现在15.7 cal kaBP。该事件与热带太平洋及其边缘海表层水冰消期δ 13 C最小值具有相当的同步性。DGKS 9603孔样中的浮游有孔虫动物群和δ 18 O记录均未显示上升流和河流径流增强的迹象，因此，DGKS 9603孔样中浮游有孔虫记录中广泛的冰消期δ 13 C极小值事件可能是热带太平洋冰消期地表水直接影响的结果。此次冲绳海槽事件的确认为热带低纬太平洋水演化在大区域乃至全球碳循环中起着关键作用提供了新的证据。
The equatorial Pacific upwelling zone has been suspected of playing an important role in the global atmospheric CO2 changes associated with glacial-interglacial cycles. In order to assess the influencing scope of the surface water deglacial δ13C minimum in the tropical low-latitude Pacific, the core DGKS9603, collected from the middle Okinawa Trough, was examined for δ13C records of planktonic foraminifera N. dutertrei and G. ruber. The planktonic foraminiferal δ13C records show a clear decreasing event from 20 to 6 cal. kaBP., which is characterized by long duration of about 14 ka and amplitude shift of 0.4 × 10−3. Its minimum value occurred at 15.7 cal kaBP. The event shows fairly synchrony with the surface water deglacial δ13C minimum identified in the tropical Pacific and its marginal seas. Because there is no evidence in planktonic foraminiferal fauna and δ18O records for upwelling and river runoff enhancement, the broad deglacial δ13C minimum event in planktonic foraminiferal records revealed in core DGKS9603 might have been the direct influencing result of the deglacial surface water of the tropical Pacific. The identification for the event in the Okinawa Trough provides new evidence that the water evolution in the tropical low-latitude Pacific plays a key role in large regional, even global carbon cycle.