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A high-resolution history of vegetation and climate history on sunda Shelf since the last glaciation

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Science China Earth Sciences 2007年第1期50卷 75-80页

作者： Karl STATTEGGER Institute of Geosciences University of Kiel Olshausenstrasse 40 Kiel 24118 Germany

This paper presents 16500-year-long high-resolution pollen and spore records from sediments of core 18287 on the continental slope of the southern South China Sea. In the period of 16.5―13.9 ka B.P., the low-mountain rainforest dominated the continental slope of the South China Sea. And in the period of 13.9―10.2 ka B.P., the lowland rainforest and ferns expanded greatly, while the low-mountain rainforest shrank, which indicated a warming at the last deglaciation. Also during this period, the pollen sedi-mentation rates reduced sufficiently. This might imply a rise of the sea level and therefore the sub-mergence of the shelf, resulting in the broadening of the distance between the source area and the slope. After 10.2 ka B.P, decreasing of the fern indicates the early Holocene (10.2―7 ka B.P.) is a cold period, while the increasing of fern marks the rising temperature (7―3.6 ka B.P.).

关键词： sunda Slope pollen and spores vegetation last deglaciation Holocene.

Water Mass Characteristics and Stratification at the Shallow sunda Shelf of Southern South China Sea

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Open Journal of Marine Science 2015年第4期5卷 455-467页

作者： Nur Hidayah Roseli Mohd Fadzil Akhir Mohd Lokman Husain Fredolin Tangang Azizi Ali Institute of Oceanography and Environment Universiti Malaysia Terengganu Kuala Terengganu Malaysia Research Centre for Tropical Climate Change System National University of Malaysia Bangi Malaysia

CTD data obtained from two oceanographic cruises during June and October 2012 were used to define the water mass characteristics and degree of stratification at the shallow sunda shelf located at the southern South China Sea. The water masses during both cruises showed characteristics similar (southwest monsoon) to those observed in the adjacent regions. A clustering method was used in which three water masses were classified from the composite dataset. There are WM1 (T 29°C - 31°C, S 32 - 33.5 psu, & σT, ~19.5 - 20.7 kg/m3), WM2 (T 25°C - 29°C, S 32.8 - 33.8 psu, & σT, ~22.3 - 23 kg/m3) and WM3 (T 23°C - 25°C, S33.5 - 34.0, & σT ~22.3 - 23.3 kg/m3). Even though the water masses found were characterized under southwest monsoon characteristics, the degrees of stratification obtained varied between these cruises. The stability of the stratification also plays roles in the distribution of the water masses in the water column. WM2 was found in thermocline layer and most dominant in June compared to in October. In June, WM3 was found under the thermocline layer and absent in October. The stable thermocline caused the denser WM3 cannot mixed with WM2. Higher temperatures and weaker winds during June may have caused the strong stratification, while decreasing temperature and stronger winds of an upcoming northeast monsoon enhanced the vertical mixing during October.

关键词： Water Masses Stratification Brunt-Vaisala Frequency sunda Shelf South China Sea

The biogenic silica variation and paleoproductivity evolution in the eastern Indian Ocean during the past 20 000 a

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Acta Oceanologica Sinica 2019年第1期38卷 78-84页

作者： Yonghang Xu Liang Wang Zhikun Lai Xiaohui Xu Feng Wang Shengfa Liu Xuefa Shi Rainer Arief Troa Rina Zuraida Eko Triarso Marfasran Hendrizan Laboratory of Ocean and Coast Geology Third Institute of Oceanography Ministry of Natural Resources Laboratory for Marine Geology Pilot National Laboratory for Marine Science and Technology (Qingdao) Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of Oceanography Ministry of Natural Resources Marine Research Center Agency of Research and Human Resources for Marine and Fisheries Marine Geological Institute Agency for Research and Development for Energy and Mineral Resources Research Center for Geotechnology Indonesia Institute of Sciences

The biogenic silica of sediment samples from Core CJ01-185 which is collected from the eastern India Ocean off the sunda Strait is analyzed to evaluate the impact of the opening of the sunda Strait on a paleoproductivity evolution. The new results indicate that the biogenic silica mass values of Core CJ01-185 show the lowest 0.86% in the last glacial period, and reach its maxima of 1.89% in the late Holocene. Furthermore, the biogenic silica mass accumulation rate(MARBSi) values also vary with much higher during the late Holocene than during the last glaciation. The input of additional terrigenous materials from the Java Sea has enhanced the paleoproductivity and increased the biogenic silica mass and MARBSi values after the opening of the sunda Strait. It is suggested that the paleoproductivity in the study area is mainly influenced by the southeast monsoon and upwelling before the opening of the sunda Strait. However, the paleoproductivity is dominated by the terrigenous materials input other than by the southeast monsoon or upwelling in the Holocene.

关键词： biogenic silica paleoproductivity sunda Strait eastern India Ocean

Estimation of the 2010 Mentawai tsunami earthquake rupture process from joint inversion of teleseismic and strong ground motion data

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Geodesy and Geodynamics 2015年第3期6卷 180-186页

作者： Zhang Lifen Liao Wulin Li Jinggang Wang Qiuliang Key Laboratory of Earthquake Geodesy Institute of Seismology China Earthquake Administration Institute of Geophysics China Earthquake Administration Wuhan Base of Institute of Crustal Dynamics China Earthquake Administration

Joint inversion of teleseismic body-wave data and strong ground motion waveforms was applied to determine the rupture process of the 2010 Mentawai earthquake. To obtain stable solutions, smoothing and non-negative constraints were introduced. A total of 33 teleseismic stations and 5 strong ground motion stations supplied data. The teleseismic and strong ground motion data were separately windowed for 150 s and 250 s and bandpass filtered with frequencies of 0.001e1.0 Hz and 0.005e0.5 Hz, respectively. The finitefault model was established with length and width of 190 km and 70 km, and the initial seismic source parameters were set by referring to centroid moment tensor(CMT) solutions. Joint inversion results indicate that the focal mechanism of this earthquake is thrust fault type, and the strike, dip, and rake angles are generally in accordance with CMT results. The seismic moment was determined as 5.814 1020Nm(Mw7.8) and source duration was about 102 s, which is greater than those of other earthquakes of similar magnitude. The rupture nucleated near the hypocenter and then propagated along the strike direction to the northwest, with a maximum slip of 3.9 m. Large uncertainties regarding the amount of slip retrieved using different inversion methods still exist; however, the conclusion that the majority of slip occurred far from the islands at very shallow depths was found to be robust. The 2010 Mentawai earthquake was categorized as a tsunami earthquake because of the long rupture duration and the generation of a tsunami much larger than was expected for an earthquake of its magnitude.

关键词： 2010 Mentawai earthquake Rupture process Tsunami Joint inversion Teleseismic recording Strong ground motion sunda meg