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Adsorption behavior of CO_(2) in magnesite micro-pores at high temperature and pressure

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Geoscience Frontiers 2021年第2期12卷 991-999页

作者： Longxing Yang Lei Liu Hong Liu Li Yi Xiaoyu Gu Haibo Liu Hanyu Wang United laboratory of High-Pressure Physics and earthquake science Key Laboratory of Earthquake PredictionInstitute of Earthquake ForecastingCEABeijing100036China

The fluid inclusions in mantle rocks and melt indicated that a large amount of CO_(2)fluid exists in the deep earth,which is of great significance for understanding the deep carbon cycle and the composition of ***,it was also suggested that carbonate minerals were likely to be the main host of mantle *** the same time,the distribution and behavior of carbon in the mantle still remain a *** this paper,the adsorption behavior and occurrence characteristics of supercritical CO_(2)in magnesite(MgCO3)pores were studied by the Grand Canonical Monte Carlo method(GCMC)under the different conditions of CO_(2)pressures(0–100 MPa),temperatures(350–1500 K)and the pore sizes(7.5–30Å).The simulated results showed that the adsorption of CO_(2)in magnesite was a physical adsorption,which was mainly controlled by the intermolecular *** gas adsorption became more stable when the adsorption site shifted from the high energy site to the low energy site with increasing pressure(P)and decreasing temperature(T)and pore *** the same time,the variations of excess adsorption amounts of CO_(2)in the pores of magnesite(Nexcess)under the different conditions were quantitatively *** was found that the Nexcess decreased with increasing T,but increased with increasing P and pore *** results favor understanding the CO_(2)migration,seismic precursor observations,and heat transfer process in the deep earth.

关键词： CO_(2) Magnesite Adsorption Nexcess GCMC Carbon cycle

Characteristics of Late-Quaternary Activity and Seismic Risk of the Northeastern Section of the Longmenshan Fault Zone

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Acta Geologica Sinica(English Edition) 2013年第6期87卷 1674-1689页

作者： WANG Mingming ZHOU Bengang YANG Xiaoping XIE Chao GAO Xianglin key laboratory of Active Tectonics and Volcano Institute of Geology CEA Sichuan Seistech Corporation Ltd. key laboratory of earthquake prediction Institute of Earthquake Science CEA institute of Geology CEA

Following the 2008 Wenchuan M8 earthquake,the seismic risk of the northeastern section of the Longmenshan fault zone and the adjacent Hanzhong basin has become an issue that receives much *** is facing,however,the problem of a lack of sufficient data because of little previous work in these *** northeastern section of the Longmenshan fault zone includes three major faults：the Qingchuan fault,Chaba-Lin＇ansi fault,and Liangshan south margin fault,with the Hanzhong basin at the northern *** paper presents investigations of the geometry,motion nature,and activity ages of these three faults,and reveals that they are strike slip with normal faulting,with latest activity in the Late *** implies that this section of the Longmenshan fault zone has been in an extensional setting,probably associated with the influence of the Hanzhong *** analysis of the tectonic relationship between the Longmenshan fault zone and the Hanzhong basin,this work verifies that the Qingchuan fault played an important role in the evolution of the Hanzhong basin,and further studies the evolution model of this ***,with consideration of the tectonic setting of the Longmenshan fault zone and the Hanzhong basin as well as seismicity of surrounding areas,this work suggests that this region has no tectonic conditions for great earthquakes and only potential strong events in the future.

关键词： Seismic risk northeastern Longmenshan fault zone Hanzhong basin Late-Quaternary activity

First-principles simulation of Raman spectra and structural properties of quartz up to 5 GPa

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Chinese Physics B 2015年第12期24卷 517-525页

作者：刘雷吕超甲庄春强易丽刘红杜建国 key laboratory of earthquake prediction Institute of Earthquake ScienceChina Earthquake Administration institute of Microstructure and Properties of Advanced Materials Beijing University of Technology

The crystal structure and Raman spectra of quartz are calculated by using first-principles method in a pressure range from 0 to 5 GPa. The results show that the lattice constants（a, c, and V） decrease with increasing pressure and the a-axis is more compressible than the c axis. The Si–O bond distance decreases with increasing pressure, which is in contrast to experimental results reported by Hazen et al. [Hazen R M, Finger L W, Hemley R J and Mao H K 1989 Solid State Communications 725 507–511], and Glinnemann et al. [Glinnemann J, King H E Jr, Schulz H, Hahn T, La Placa S J and Dacol F 1992 Z. Kristallogr. 198 177–212]. The most striking changes are of inter-tetrahedral O–O distances and Si–O–Si angles. The volume of the SiO4^4- tetrahedron decreased by 0.9%（from 0 to 5 GPa）, which suggests that it is relatively *** models of the quartz modes are identified by visualizing the associated atomic motions. Raman vibrations are mainly controlled by the deformation of the Si O4-4tetrahedron and the changes in the Si–O–Si bonds. Vibrational directions and intensities of atoms in all Raman modes just show little deviations when pressure increases from 0 to 5 *** pressure derivatives（dνi/d P） of the 12 Raman frequencies are obtained at 0 GPa–5 GPa. The calculated results show that first-principles methods can well describe the high-pressure structural properties and Raman spectra of quartz. The combination of first-principles simulations of the Raman frequencies of minerals and Raman spectroscopy experiments is a useful tool for exploring the stress conditions within the Earth.

关键词： structural properties Raman mode quartz first principles

Impact of ocean data assimilation on the seasonal forecast of the 2014/15 marine heatwave in the Northeast Pacific Ocean

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Atmospheric and Oceanic science Letters 2025年第1期18卷 24-31页

作者： Tiantian Tang Jiaying He Huihang Sun Jingjia Luo institute for Climate and Application Research(ICAR)/key laboratory of Meteorological Disaster Nanjing University of Information Science and TechnologyNanjingChina

A remarkable marine heatwave,known as the“Blob”,occurred in the Northeast Pacific Ocean from late 2013 to early 2016,which displayed strong warm anomalies extending from the surface to a depth of 300 *** study employed two assimilation schemes based on the global Climate Forecast System of Nanjing University of Information science(NUIST-CFS 1.0)to investigate the impact of ocean data assimilation on the seasonal prediction of this extreme marine *** sea surface temperature(SST)nudging scheme assimilates SST only,while the deterministic ensemble Kalman filter(EnKF)scheme assimilates observations from the surface to the deep *** latter notably improves the forecasting skill for subsurface temperature anomalies,especially at the depth of 100-300 m(the lower layer),outperforming the SST nudging *** excels in predicting both horizontal and vertical heat transport in the lower layer,contributing to improved forecasts of the lower-layer warming during the *** improvements stem from the assimilation of subsurface observational data,which are important in predicting the upper-ocean *** results suggest that assimilating ocean data with the EnKF scheme significantly enhances the accuracy in predicting subsurface temperature anomalies during the Blob and offers better understanding of its underlying mechanisms.

关键词： Seasonal forecast Ocean data assimilation Marine heatwave Subsurface temperature

SEM Numerical Simulation of Vertical and Inclined Fault Zone Trapped Waves and Comparison of Their Wave Fields

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earthquake Research in China 2015年第2期29卷 176-189页

作者： Xu Hongwei Wang Weijun key laboratory of earthquake prediction institute of earthquake science CEA

Fault zone trapped waves （FZTWs） mainly travel along the fractured fault zone （FZ） which is of low velocity and high attenuation. FZTWs often carry significant information about a fault＇s internal structure, so it is important to understand their wave field characteristics for FZ structure inversion. Most previous simulations are based on vertical faults, while in this paper we implement the FZTW simulations on vertical or inclined faults and compare their wave fields in both time and frequency domains. The results show that the existence of fault zone and inclined angle of fault can significantly influence the features of waves near faults. In amplitude, a fault zone can generate a larger amplitude of waves. The velocity contrast between two wails of fault may lead to amplification of amplitudes in the low velocity fault wall. In frequency, a fault zone tends to influence the waves in the low frequency range. In a pattern of particle polarization of FZTWs, it tends to be single direction for vertical faults but fork to multiple directions for inclined faults, which might provide a new way to study the fault zone with FZTWs. These conclusions may be valuable for FZ structure inversion, and will enhance the knowledge on near-fault strong ground motions.

关键词： Fault zone trapped waves SEM simulation inclined fault Wave fieldcharacteristic

The focal depths of the 2008 Panzhihua earthquake sequence and the stress field in the source region

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science China Earth sciences 2020年第3期63卷 439-451页

作者： Yan LUO Li ZHAO Jianhui TIAN key laboratory of earthquake prediction Institute of Earthquake ForecastingCEABeijing 100036China School of Earth and Space sciences Peking UniversityBeijing 100871China

Focal depths of the 2008 Ms6.1 Panzhihua earthquake sequence and tectonic stress field in the source area are *** depths of 24 earthquakes in Panzhihua earthquake sequence with a magnitude M≥3.0 were determined using the seismic depth phase sPL;additionally,the focal depths of 232 earthquakes were measured by fitting the threecomponent waveforms of the P and S *** source depth of the main shock is^12 *** majority of the aftershocks with magnitude M≥3.0 occurred in the brittle upper crust at the depths range of 12-18 ***,the Source mechanisms of the 232events around the Panzhihua earthquake source area were determined,and the results show that the earthquakes have predominantly strike-slip mechanisms in the Dianzhong Block,but display complexity of the focal mechanisms outside and near the boundary of the Dianzhong *** 232 earthquake mechanisms from this study are combined with the solutions from the Global Centroid Moment Tensor (GCMT) catalog to derive 2D stress *** inversion results show that the Dianzhong block is predominantly under a strike slip faulting regime and the direction of the maximum principal compressionσ1 is northwestsoutheast (NW-SE)-*** distribution is coincide with GPS velocity ***,orientations of principal stress axes as well as the faulting types change outside and near the Dianzhong *** results show that the tectonic stress field in the study area is predominantly controlled by the southeast (SE)-trending horizontal movement and clockwise rotation of the Dianzhong block as a result of the eastward movement of eastern Tibetan meeting the old and rigid South China block (SCB).The Panzhihua earthquake ruptured at^12 km depth where the tectonic stress regime is under the SE-direction horizontal compression and the NE-direction horizontal extension.

关键词： Panzhihua earthquake sequence Depth phase Focal mechanism solution Tectonic stress field

Anisotropic zoning in the upper crust of the Tianshan Tectonic Belt

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science China Earth sciences 2021年第4期64卷 651-666页

作者： Jin LI Yuan GAO Qiong WANG earthquake Administration of Xinjiang Uygur Autonomous Region Urumqi 830011China key laboratory of earthquake prediction Institute of Earthquake ForecastingChina Earthquake AdministrationBeijing 100036China

The Tianshan Tectonic Belt is an intracontinental orogenic belt formed by continental convergence that has undergone long-term tectonic evolution. The reactivation that began during the Cenozoic Period has led to complex structural changes. The goals of this study are to review the seismic observational data obtained during 2009–2019 in the Xinjiang regional seismic network and analyze the anisotropy of the upper crust in the Tianshan area. Therefore, a shear-wave splitting system was adopted to collect and analyze shear-wave splitting parameters of 33 stations in the study area. The anisotropy of the upper crust of the Tianshan is spatially diverse, and the dominant polarization directions of fast shear-wave reflect the spatial variations of regional tectonic stress. In addition, the time delays of slow waves are proportional to the intensities of anisotropy in the upper crustal medium. The dominant polarization direction of the fast waves in the western segment of the North Tianshan Mountain,northwestern corner of the Tarim Basin, and northeastern edge of Pamir is consistent with the tectonic stress fields in the area. In the northern part of the Keping Block, the dominant polarization directions of the fast waves are consistent with the fault trends;however, they are at a high angle to the dominant directions of the regional tectonic stress field indicating that the anisotropy is affected by the faults in the area. The anisotropy of the eastern segment of the South Tianshan Mountains and the surrounding area of Urumqi are affected by the local stress field and fault structure. The polarization directions at some of the stations are subparallel to the directions of the regional principal stress. However, for other stations, the polarization directions are aligned with the neighboring faults. The polarization directions of the fast waves in most of the study area are consistent with the local tectonic stress fields. Thus, stress compression phenomena such as the Ta

关键词： Tianshan Tectonic Belt Seismic anisotropy Shear-wave splitting Tectonic stress

Gravity pattern in southeast margin of Tibetan Plateau and its implications to tectonics and large earthquakes

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Earth and Planetary Physics 2019年第5期3卷 425-434页

作者： Yue Wu Yuan Gao key laboratory of earthquake prediction Institute of Earthquake ForecastingChina Earthquake Administration

There are many active faults in the southeast margin of Tibetan Plateau,where three large active faults zones,the Longmenshan,Xianshuihe and Anninghe,merge to form a"Y"*** crustal deformation and a complicated fault distribution accompany strong earthquake activity in this *** this paper,we investigate a multi-scale gravity anomaly in the southeastern margin of the Tibetan Plateau using the wavelet transform;we find that the pattern of the gravity field is closely related to the fault system in the study *** the characteristics of this Bouguer gravity anomaly at different orders indicates that the eastern Himalayan syntaxis has produced a strong eastward push during its northward movement,resulting in a shortening of the crust from west to east and a rapid uplift of the Tibetan *** Songpan–Garzêand Sichuan–Yunnan blocks have been forced to slip and extrude southward and eastward *** distributions of seven large earthquakes from 1970 to 2018 reflects the relationship between large earthquakes and characteristics of the gravity *** the tectonic backgrounds of several earthquakes reveals that the large earthquakes occur usually in the high gravity anomaly gradient zone,which corresponds in general to the boundary zones of the *** infer that large earthquakes occur primarily in high Bouguer gravity anomaly zones in the upper crust,while low Bouguer gravity anomalies encompass the lower crust and the uppermost mantle.

关键词： southeast margin of Tibetan Plateau Bouguer gravity anomaly(BA) wavelet transform(WT)and multiscale analysis(MA) focal mechanism of earthquake gradient zone

Research of the Differential Uplifting in the Palongzangbu Region Based on the Synthesis of the Watershed Index and Seismic Data

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earthquake Research in China 2018年第1期32卷 64-79页

作者： Wang Lin Zhao Yan Tian Qinjian Li Wenqiao Xu Yueren key laboratory of earthquake prediction Institute of Earthquake ForecastingCEA

Research on the differential uplifting in the Palongzangbu region is crucial to understanding the tectonic deformation mechanism and establishing the model of the faulted blocks in the region of the east structural *** this paper,based on the ASTER-30m DEM,we calculate the hypsometry index(HI)of 19 watersheds in the Palongzangbu region,and study the differential uplifting in this region combining with seismic data,the ground deposition and erosion *** result shows that the spatial distribution of the HI value can reflect the differential uplifting in the study *** uplifting exists within different zones,and there are 2 relative strong uplifting *** center is near the east structural knot,and the other lies between the Lhari fault and Nujiang fault at their converging ***,the watershed evolution,seismic activity,and ground deposition and erosion process are closely related to each other,and they constitute a chain of evidence which reveals the whole process from the tectonic movement underground to the landform evolution on the surface.

关键词： Watershed Hypsometry Index GIS DEM Differential Tectonic Uplifting East Structural Knot