Quantitative Distribution of Deep-water Benthos in Western Central Pacific

Altogether 10 surfaces and 8 cores were sampled quantitatively from the Western Central Pacific(4°00′S—5°00′N, 160°00′—165°00′E and 2°00′—10°00′S, 170°00′—173°20′E) in 1978 and 1979. The results of preliminary analysis show that the faunal composition was quite simlpe, only eight species of macrobenthic invertebrates, four species of Polychaete, two     

The physical properties of primordial intergalactic gas — re-examination of self-gravitating models of lyman-alpha forest

The physical state of optically thin, primordial gas in intergalactic space at redshift about Z=2.5 is re-examined, assuming the gas is in ionzation and thermal equilibrium by the integrated UV flux from QSOs. For densities in the range 10^–5–10^–2 cm^–3, the structure of the gas can be well described by an isothermal polytrope of infinite index. The L absorbing clouds observed in the spectra of distant QSOs may arise in such self-gravitating intergalactic clouds. Some properties of the clouds are discussed with reference to recent observations and equilibrium models.This work is partially supported by CNSF.     

Intensification of decadal and multi-decadal sea level variability in the western tropical Pacific during recent decades

Previous studies have linked the rapid sea level rise (SLR) in the western tropical Pacific (WTP) since the early 1990s to the Pacific decadal climate modes, notably the Pacific Decadal Oscillation in the north Pacific or Interdecadal Pacific Oscillation (IPO) considering its basin wide signature. Here, the authors investigate the changing patterns of decadal (10–20 years) and multidecadal (>20 years) sea level variability (global mean SLR removed) in the Pacific associated with the IPO, by analyzing satellite and in situ observations, together with reconstructed and reanalysis products, and performing ocean and atmosphere model experiments. Robust intensification is detected for both decadal and multidecadal sea level variability in the WTP since the early 1990s. The IPO intensity, however, did not increase and thus cannot explain the faster SLR. The observed, accelerated WTP SLR results from the combined effects of Indian Ocean and WTP warming and central-eastern tropical Pacific cooling associated with the IPO cold transition. The warm Indian Ocean acts in concert with the warm WTP and cold central-eastern tropical Pacific to drive intensified easterlies and negative Ekman pumping velocity in western-central tropical Pacific, thereby enhancing the western tropical Pacific SLR. On decadal timescales, the intensified sea level variability since the late 1980s or early 1990s results from the “out of phase” relationship of sea surface temperature anomalies between the Indian and central-eastern tropical Pacific since 1985, which produces “in phase” effects on the WTP sea level variability.     

The influences of mining subsidence on the ecological environment and public infrastructure: a case study at the Haolaigou Iron Ore Mine in Baotou,China

The scope and extent of mine subsidence caused by exploitation of metal ores are usually low. However, in some cases, owing to such factors as special geological conditions in ore body, backward mining technology and unsound management systems, exploitation of metal ores would also lead to a large area of mine subsidence, causing great damages to the mining environment and infrastructure. A serious mine subsidence happened in January 2007 at the Haolaigou Iron Ore Mine has caused a huge collapse pit on the earth’s surfaces. This provides a suitable place to study the influence of mine subsidence. Based on former research results, a 3D geological model is constructed using the ROCK MODEL software developed by authors’ group. Based on in situ geological conditions, the range of orebody mining and the physical and mechanical parameters of rock and soil mass were determined by inverse analysis. Creep analysis of the collapse pit was also performed. Furthermore, the elastoplastic and creep of the secondary collapse were computed, and the final range of the collapse pit was predicted. Finally, the influences of mining subsidence on the ecological environment and public infrastructure are discussed and control measures were proposed. The results indicate that the collapse pit would not affect the road even if creep is considered; however, the secondary collapse would influence the road. So the collapse pit should be dealt with as soon as possible.