Modeling Groundwater Inflow to the New Crater Lake at Kīlauea Volcano,Hawai'i     

S. E. Ingebritsen  A. F. Flinders  J. P. Kauahikaua  P. A. Hsieh 《Ground water》2021,59(1):7-15

During the 2018 eruption of Kīlauea Volcano, Hawai'i, scientists relied heavily on a conceptual model of explosive eruptions triggered when lava-lake levels drop below the water table. Numerical modeling of multiphase groundwater flow and heat transport revealed that, contrary to expectations, liquid water inflow to the drained magma conduit would likely be delayed by months to years, owing to the inability of liquid water to transit a zone of very hot rock. The summit of Kīlauea subsequently experienced an ∼2-month period of consistent repeated collapses, and the crater now extends below the equilibrium position of the water table. Liquid water first emerged into the deepened crater in late July 2019. The timing of first appearance of liquid water (about 14 months postcollapse) and the rate of crater lake filling (currently ∼27 kg/s) were well-predicted by the numerical modeling done in late spring 2018, which forecast liquid inflow after 3 to 24 months at rates of 10 to 100 kg/s. A second-generation groundwater model, reflecting the current crater geometry, forecasts lake filling over the next several years. The successful 2018 to present forecasts with both models are based on unadjusted in situ permeability estimates (1 to 6 × 10⁻¹⁴ m²) and water-table elevations (600 to 800 m) from a nearby research drillhole and geophysical surveys. Important unknowns that affect the reliability of longer-term forecasts include the equilibrium water-table geometry, the rate of evaporation from the hot and growing crater lake (currently ∼29,000 m² at 70-80 °C), and heterogenous permeability changes caused by the 2018 collapse.  相似文献   

64层锥束CT扫描的优化系统     

谢强  Eugene Williams  唐向阳  Brian Grekowicz  Roy Nilsen  Sandeep Dutta  Robert Senzig 《CT理论与应用研究》2005,14(4):59-67

近年来X射线断层成像(CT)技术获得了突飞猛进的发展,自1998年推出4层螺旋CT后,CT扫描设备在容积覆盖,空间分辨率,扫描速度,切片数方面取得了长足进展.这不仅给医学应用带来了深远的影响,同时也给CT系统设计提出了巨大的挑战.容积CT(VCT)的设计过程引入了各种策略来战胜其复杂性.这些方法学包括:理论分析,系统性能预测的图像分析工具,各种基于专家背对背评价的参数优化.本文论述了64层CT系统设计中的一些考虑因素及优化过程.这些设计过程保证了锥束CT的优化性能.首批客户的应用反馈显示了我们设计实践的有效率性.  相似文献   

High frequency site amplification evaluated from Borehole data in the Taipei Basin     

Ming-Wey Huang  Jeen-Hwa Wang  Hung-Hao Hsieh  Kuo-Liang Wen 《Journal of Seismology》2009,13(4):601-611

Based on the quarter-wavelength approximation, the frequency-dependent site amplifications, A(f ), at 18 free-field strong-motion stations in and near the Taipei Basin are evaluated from well-logging data. The V ₃₀, which is the average of the S-wave velocities in the topmost 30 m, is a significant factor in classifying the sites. Results show that the site amplifications at all sites in study are larger than 1 and functions of frequency. Compared with the Haskell method, the quarter-wavelength approximation is almost an average and a good representation of overall amplifications. It is noted that the site amplifications evaluated in this study can apply only to frequencies greater than about 1.1 Hz for class C sites and 3.1 Hz for class D.  相似文献   

Development of a two-stage washing and biodegradation system to remediate octachlorinated dibenzo-<Emphasis Type="Italic">p</Emphasis>-dioxin-contaminated soils     

J. L. Lin  C. D. Dong  C. W. Chen  S. H. Chen  T. E. Hsieh  C. M. Kao 《International Journal of Environmental Science and Technology》2017,14(9):1919-1930

A two-stage system for octachlorinated dibenzo-p-dioxin (OCDD)-contaminated soil remediation was developed. Soil washing using emulsified oil (EO) was applied in the first stage for OCDD extraction followed by the second stage of bioremediation using P. mendocina NSYSU for remaining OCDD biodegradation. The major tasks included (1) determination of optimal soil washing conditions for OCDD extraction by EO, (2) evaluation of feasibility of OCDD biodegradation by P. mendocina NSYSU under aerobic cometabolic conditions using EO as the primary substrate, and (3) assessment of the effectiveness of OCDD removal using the two-stage system. During the soil washing stage, EO with two different oil-to-water ratios (1:50 and 1:200) and pore volumes were tested with initial soil OCDD concentration of 21,000 µg/kg. Results indicate that EO could effectively improve the solubility and desorption of OCDD in soils. Up to 74% of OCDD removal could be obtained after washing with 60 PVs of EO and dilution factor of 50. After the soil washing process, enriched P. mendocina NSYSU solution was added into the reactor to enhance the aerobic biodegradation of remaining OCDD in soils. P. mendocina NSYSU could use adsorbed EO globules as substrates and caused significant OCDD degradation via the aerobic cometabolic mechanism. Approximately 82% of the remaining OCDD could be removed after 50 days of operation, and P. mendocina NSYSU played important roles in OCDD biodegradation. Up to 87% of OCDD was removed through the EO washing and biodegradation process. The two-stage system is a potential technology to remediate dioxin-contaminated soils.  相似文献   

Corrigendum to “Analysis of black carbon in sediments and soils using multi-element scanning thermal analysis (MESTA)” [Org. Geochem. 39 (2008) 1562–1571]     

Y.P. Hsieh  G.C. Bugna 《Organic Geochemistry》2009,40(2):292

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First observation of energetic neutral atoms in the Venus environment     

A. Galli  P. Wurz  S. Barabash  Y. Futaana  H. Gunell  R. Lundin  K. Brinkfeldt  N. Krupp  W. Baumjohann  T.L. Zhang  A.J. Coates  D.O. Kataria  K.C. Hsieh  J.A. Sauvaud  C. Mazelle  M. Grande  T. Sales  P. Riihela  J. Kozyra  S. McKenna-Lawlor  R. Cerulli-Irelli  A. Milillo  E. Roelof  C.T. Russell  D. Winningham  J. Scherrer 《Planetary and Space Science》2008,56(6):807-811

The ASPERA-4 instrument on board the Venus Express spacecraft offers for the first time the possibility to directly measure the emission of energetic neutral atoms (ENAs) in the vicinity of Venus. When the spacecraft is inside the Venus shadow a distinct signal of hydrogen ENAs usually is detected. It is observed as a narrow tailward stream, coming from the dayside exosphere around the Sun direction. The intensity of the signal reaches several , which is consistent with present theories of the plasma and neutral particle distributions around Venus.  相似文献   

On determining magnetohydrodynamic shock parameters θ_Bn and M_A     

J.K. Chao  K.C. Hsieh 《Planetary and Space Science》1984,32(5):641-646

In a collisionless plasma, the magnetohydrodynamic shock structure, the associated waves and turbulence depend strongly on the shock parameters θ_Bn and M_A, where θ_Bn is the angle between the upstream magnetic field and the shock normal and M_A is the upstream Alfvén Mach-number. A method is given to determine θ_Bn and M_A and their estimated errors for all types of shocks without knowing the shock normals. The only measured quantities needed to determine θ_Bn and M_A are the plasma density and magnetic field on both sides of the shock. The estimated error of θ_Bn using our method can be obtained in a straightforward manner and is more reliable than that based on the calculated shock normal and the upstream magnetic field. Its simplicity and ability to handle parallel shocks as well as perpendicular and oblique shocks are illustrated by examples. This method should be useful for characterizing the types of shocks from analyzing the copious amount of data on magnetohydrodynamic (MHD) shocks found in space.  相似文献   

NOTE ON THE GEOMORPHOLOGY OF THE NORTH SHENSI BASIN     

謝家榮 《地质学报》1933,(1)

The geology of the north Shensi basin has been studied to some detail bythe American geologists Fuller,Clapp and others~1 in an oil exploration partysent out in 1914 under the joint auspices of the Chinese National Oil Administra-  相似文献   

EFFECT OF CIRCULATION LOW LATITUDES ON THE WEATHER OF MIDDLE LATITUDES——THE IDEA OF MID-RANGE AND SHORT-RANGE FORECASTS OF RAINSTORMS     

谢义炳  张镡  蒋尚城 《海洋学报》1981,3(4):546-553

There is a close relation between the circulations of the low latitudes over the ocean as well as their. variations and precipitation in China.Rainstorms and droughts which often cause disasters are two extreme cases of precipitation. Therefore it is practically and theoretically significant to forecast both of them. A series of analyses on the predominant rainstorms processes in mid-summer in North China were made from 1975 to 1977[1,2],and the method was used.As a consequence, a preliminary conclusion has been reached.  相似文献   

3-D Shear Wave Velocity Structure of the Crust and Upper Mantle in South China Sea and its Surrounding Regions by Surface Wave Dispersion Analysis   总被引：5，自引：0，他引：5  

Hsin-Hung Wu  Yi-Ben Tsai  Tung-Yi Lee  Ching-Hua Lo  Chao-Hui Hsieh  Dinh Van Toan 《Marine Geophysical Researches》2004,25(1-2):5-27

In this study, we construct a 3-D shear wave velocity structure of the crust and upper mantle in South China Sea and its surrounding regions by surface wave dispersion analysis. We use the multiple filter technique to calculate the group velocity dispersion curves of fundamental mode Rayleigh and Love waves with periods from 14 s to 120 s for earthquakes occurred around the Southeast Asia. We divide the study region (80° E–140° E, 16° S–32° N) into 3° × 3° blocks and use the constrained block inversion method to get the regionalized dispersion curve for each block. At some chosen periods, we put together laterally the regionalized group velocities from different blocks at the same period to get group velocity image maps. These maps show that there is significant heterogeneity in the group velocity of the study region. The dispersion curve of each block was then processed by surface wave inversion method to obtain the shear wave velocity structure. Finally, we put the shear wave velocity structures of all the blocks together to obtain the three-dimensional shear wave velocity structure of crust and upper mantle. The three-dimensional shear wave velocity structure shows that the shear wave velocity distribution in the crust and upper mantle of the South China Sea and its surrounding regions displays significant heterogeneity. There are significant differences among the crustal thickness, the lithospheric thickness and the shear wave velocity of the lid in upper mantle of different structure units. This study shows that the South China Sea Basin, southeast Sulu Sea Basin and Celebes Sea Basin have thinner crust. The thickness of crust in South China Sea Basin is 5–10 km; in Indochina is 25–40 km; in Peninsular Malaysia is 30–35 km; in Borneo is 30–35 km; in Palawan is 35 km; in the Philippine Islands is 30–35 km, in Sunda Shelf is 30–35 km, in Southeast China is 30–40 km, in West Philippine Basin is 5–10 km. The South China Sea Basin has a lithosphere with thickness of about 45–50 km, and the shear wave velocity of its lid is about 4.3–4.7 km/s; Indochina has a lithosphere with thickness of about 55–70 km, and the shear wave velocity of its lid is about 4.3–4.5 km/s; Borneo has a lithosphere with thickness of about 55–60 km, and the shear wave velocity of its lid is about 4.1–4.3 km/s; the Philippine Islands has a lithosphere with thickness of about 55–60 km, and the shear wave velocity of its lid is about 4.2–4.3 km/s, West Philippine Basin has a lithosphere with thickness of about 50–55 km, and the shear wave velocity of its lid is about 4.7–4.8 km/s, Sunda Self has a lithosphere with thickness of about 55–65 km, and the shear wave velocity of its lid is about 4.3 km/s. The Red-River Fault Zone probably penetrates to a depth of at least 200 km and is plausibly the boundary between the South China Block and the Indosinia Block.  相似文献