Geophysical Investigations of the South-Western Wairarapa Region of New Zealand

<p>A model of the sub-surface structure of the south-western part of the Wairarapa sedimentary basin in central New Zealand was constructed from geophysical data obtained by the author during the period 1990-1991. A total of 122 new gravity observations, eight magnetotelluric (MT) stations and approximately two kilometres of seismic refraction lines were established in the study area. All methods complemented each other in the determination of the final result. The gravity data provided the depth for the basement layer of the basin, and determined the position of a fossil fault in the region of the Wharepapa River channel. The MT and seismic data confirmed the fossil nature of the fault. The results for the boundaries determined by the MT surveys were also shown to agree with the upper layers of the gravity model. The final model presented is of a sedimentary basin with thickness of approximately 2km, with a fossil fault dividing the basin near the vicinity of the Wharepapa River. To the west of the study area is a highly anomalous region which could not be fully modelled in this study because of lack of data in this particular area.</p>

Geophysical Investigations of the South-Western Wairarapa Region of New Zealand

<p>A model of the sub-surface structure of the south-western part of the Wairarapa sedimentary basin in central New Zealand was constructed from geophysical data obtained by the author during the period 1990-1991. A total of 122 new gravity observations, eight magnetotelluric (MT) stations and approximately two kilometres of seismic refraction lines were established in the study area. All methods complemented each other in the determination of the final result. The gravity data provided the depth for the basement layer of the basin, and determined the position of a fossil fault in the region of the Wharepapa River channel. The MT and seismic data confirmed the fossil nature of the fault. The results for the boundaries determined by the MT surveys were also shown to agree with the upper layers of the gravity model. The final model presented is of a sedimentary basin with thickness of approximately 2km, with a fossil fault dividing the basin near the vicinity of the Wharepapa River. To the west of the study area is a highly anomalous region which could not be fully modelled in this study because of lack of data in this particular area.</p>

On the connection of the kinematic characteristics of the wind in tropical cyclones and anomalies of force of gravity

The existence of connections between the kinematic characteristics of wind (maximum speed and its acceleration) in a tropical cyclone and the values of gravity anomalies (vertical and horizontal components, respectively, VGA and GGA) along the paths of movement of tropical cyclones. It is shown that the change in VGA values is generally close in antiphase to changes in velocity and, to a certain extent, correlates qualitatively. Analysis of wind accelerations and the corresponding values of VGA did not reveal a clear match in their comparison. Changes in GGA values are close to changes in wind speed and at a qualitative level they correlate well except for the emergence of a shopping center on land and the movement of a shopping center in a highly anomalous region. Comparison of changes in maximum speed and acceleration of wind with changes in GGA values is performed for the first time.

Thermodynamic investigation by heat capacity measurements of κ-type dimer-Mott organic compounds with chemical pressure tuning

Thermodynamic discussion on the physical properties around the Mott boundary of the dimer-Mott system of [Formula: see text]-type (BEDT-TTF)2X system, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene and X denotes monovalent counter anions is performed by heat capacity measurements of the [Formula: see text]-(d[n,n] BEDT-TTF)2Cu[N(CN)2]Br of which donor molecules are partially deuterated. We compare temperature dependences of heat capacity of d[2,2], d[3,3] and d[4,4] compounds (defined as shown in Fig. 1) obtained in rapidly cooled and slowly cooled conditions. While the heat capacity of d[2,2] compound shows cooling rate dependence with the slight change of the absolute values Cp between 25 K and 50 K, the temperature dependences of the other compounds do not give drastic change by changing the cooling rate. The compounds of d[2,2] and d[3,3] located very close to the Mott boundary show peculiar hump structure in the C[Formula: see text]T[Formula: see text] that is related to the existence of a kind of lattice instability region around the first-order phase boundary. The temperature and chemical pressure dependences of the anomalous region are discussed in terms of the phase diagram in which the Mott boundary has peculiar rounding at low-temperature region.

APPLICATION OF THE INDUCED POLARIZATION METHOD IN SEARCH OF GOLD IN BLACK SHALE STRATA MUSHTINSKI ORE FIELD (NORTH CAUCASUS)

Рассмотрены результаты применения импульсной модификации метода вызванной поляризации (ВП) в пределах Муштинского рудного поля при проведении поисковых работ на площадях Малка-Муштинского рудного узла. Охарактеризована наиболее оптимальная система измерений, которая позволила в условиях сильно расчлененного горного рельефа и развития углеродистых сланцев выявить протяженные минерализованные зоны и стратиформноподобные залежи различного минерального типа, включающие потенциальные золоторудные тела. Показано, что наиболее эффективным для регистрации параметром ВП является заряжаемость, которая в силу своего интегрального характера в данных условиях является более помехоустойчивым параметром, чем поляризуемость. Данные по кажущемуся сопротивлению (КС) и заряжаемости проанализированы с помощью метода главных компонент, когда 1-я главная компонента соответствует обратной зависимости между логарифмом КС и заряжаемостью, а ортогональная ей 2-я главная компонента – прямой. Таким образом, аномальные области 1-й компоненты соответствуют участкам предполагаемого развития углеродистых сланцев и зон обводненных разломов, обладающих низким сопротивлением и повышенной заряжаемостью, 2-й компоненты – предполагаемым зонам окварцевания и сульфидно-вкрапленно-прожилковой минерализации, обладающих повышенным КС и повышенной заряжаемостью. The results of application of the pulse modification of the method of induced polarization (IP) within Mushtinski ore field when carrying out prospecting works on the areas of Malka-Mushtinski ore unit. Most optimal system of measurements, which allowed in a strongly dissected mountain relief and development carbonaceous shale to reveal the long, mineralized zones and mineral deposits stateformation different type, including a potential gold ore body is characterized. It is shown that the most effective to register the IP parameter is garagemate, which because of its integral nature in these conditions is a more robust parameter than the polarizability. Data for apparent resistivity (AR) and garagemate analyzed using the principal components method, when the 1st main component corresponds to an inverse relationship between the logarithm of the AR and garagemate and orthogonal her 2nd major components – direct. Thus, the anomalous region of 1-th components correspond to areas of prospective development of carbonaceous shale zones and watered faults, with a low resistance and high garagemate, 2nd components – prospective silicification zones and sulfide-vein mineralization, with high AR and high garagemate.

Moist Formulations of the Eliassen–Palm Flux and Their Connection to the Surface Westerlies

The Eliassen–Palm (EP) flux is an important diagnostic for wave propagation and wave–mean flow interaction in the atmosphere. Here, two moist formulations of the EP flux are compared with the traditional dry EP flux, and their links to the surface westerlies are analyzed using reanalysis data and simulations with GCMs. The first moist formulation of the EP flux modifies only the static stability to account for latent heat release by eddies, while the second moist formulation simply replaces all potential temperatures with equivalent potential temperatures. For reanalysis data, the peak upward EP flux in the lower troposphere is farther equatorward and stronger when the moist formulations are used, with greater changes for the second moist formulation. The moist formulations have the advantage of giving a closer relationship over the seasonal cycle between the latitudes of the peak surface westerlies and the peak upward EP flux. In simulations with a comprehensive GCM, the dry and moist upward EP fluxes shift poleward by a similar amount as the climate warms. In simulations over a wider range of climates with an idealized GCM, the surface westerlies can shift both poleward and equatorward with warming, and they are influenced by an anomalous region of dry EP flux divergence near the subtropical jet. Using moist EP fluxes weakens this anomalous divergence in the idealized GCM simulations, and the shifts in the surface westerlies can then be understood through changes in the preference for equatorward or poleward wave propagation.