Teleseismic tomography: Equation one is wrong

ABSTRACT Seismic tomography methods that use waves originating outside the volume being studied are subject to bias caused by unknown structure outside this volume. The bias is of the same mathematical order and similar magnitude as the local-structure effects being studied; failure to account for it can significantly corrupt derived structural models. This bias can be eliminated by adding to the inverse problem three unknown parameters specifying the direction and time for each incident wave, a procedure analogous to solving for event locations in local-earthquake and whole-mantle tomography. The forward problem is particularly simple: The first-order change in the arrival time at an observation point resulting from a perturbation to the incident-wave direction and time equals the change in the time of the perturbed incident wave at the point where the unperturbed ray entered the study volume. This consequence of Fermat’s principle apparently has not previously been recognized. Published teleseismic tomography models probably contain significant artifacts and need to be recomputed using the more complete theory.

Analisis Alih Fungsi Lahan Menggunakan Regresi Logistik Ordinal

The occurrence of landslides can not be separated from conditions that are prone to landslide movements such as steep slopes and high rainfall. The occurrence of landslides is also exacerbated by the indiscipline of the community in using land according to its function, which is called land conversion which can be a trigger factor for landslides. Conducting research on land use change is important to see the impact caused by human activities. The purpose of this study was to analyze the effect of land conversion on landslide hazard levels in Samigaluh District, Kulon Progo Regency. The method in this research was descriptive quantitative using primary data, namely field surveys and secondary data collection. The steps on this research were conducting field observations about the occurrence of land conversion and then retrieving level of landslide hazard at the observation point of land use change. Data analysis was performed using ordinal logistic regression. The result of the analysis showed that the p value (0.036) <0.05 which meant H0 was rejected. Thus, at the 95% confidence level it could be said that the variable of land use change affected the level of landslide hazard in Samigaluh District, Kulon Progo Regency. This output could be considered for the community to use the land according to its function. Key words: Land Function Change; Landslide; Ordinal

Registros de mamíferos presentes en el Área Marina Costera Protegida de Múltiples Usos Lafken Mapu Lahual, sur de Chile

The Lafken Mapu Lahual Coastal Marine Protected Area of Multiple Uses (Lafken Mapu Lahual), Osorno coast, southern Chile, is one of the first protected areas created in Chile during 2006, but only in 2019 its Management Plan was presented. This study provides information on its marine mammal species to be used in future biodiversity monitoring plans. The sighted mammals were recorded and counted through 18 navigation tracks and one observation point in the 2014-2015 austral breeding season. Five species were recorded systematically (one whale species, two dolphin species, one marine otter species and a one sea lion species). Two of them (Lontra felina and Balaenoptera musculus) are classified by the IUCN in the conservation category corresponding to Endangered. Laken Mapu Lahual is an important area for the species of whales that use it for their migratory route to the south of Chile.

Hydrological Analysis In Selecting Flood Discharge Method In Watershed Of Kelara River

For Engineers involved in planning and construction of water resources building, hydrology becomes very important data. In terms of planning stage in water resources especially waterworks, it is known that design flood discharge closed to field realistic conditions is often needed in order that a planned construction is able to control flood discharge. Several previous researches in choosing flood discharge selection method have diverse depending on observed watershed. One method in determining selected flood discharge by verification using Creager diagram, by comparing discharge calculation results of several Synthetic Unit Hydrograph (SUH) with infrastructure flood discharge (AWLR result) in observation point. This research aims to obtain the most suitable synthetic unit hydrograph and close to analysis result of measured discharge frequency, and Creager diagram in Kelara watershed (DAS). Based on the calculation of design flood discharge according to rainfall data using synthetic unit hydrograph of Nakayasu, ITB I, ITB II, and SCS (HEC-HMS) as well as the calculation of design flood discharge according to collected data, it is concluded that the synthetic unit hydrograph method closest to design flood discharge with measured discharge rate and Q1000 rate of Creager diagram is SCS. Flood discharge rate obtained according to HSS SCS method using HEC-HMS 4.8 application in period of 2 years is 658,40 m3/s, 25 years is 682,70 m3/s, 50 years is 787,00 m3/s, 100 years is 885,70 m3/det, and 1000 years is 1202,60 m3/s

Research the Integration of Geodetic and Geotechnical Methods in Monitoring the Horizontal Displacement of Diaphragm Walls

This article investigates the integration of geodetic and geotechnical methods for monitoringthe horizontal displacement of diaphragm walls. The results show that when the horizontal displacementis measured by the geotechnical method using an inclinometer sensor, the center point at the bottom ofthe guide pipe is usually chosen to be the origin to calculate displacements of the upper points. However,it is challenging to survey the bottom point for checking its stability directly. If this bottom point moves,the observation results will be incorrect. Thus, the guide pipe must be installed in the stable rock layer.But in the soft ground, this rock layer locates more deeply than the diaphragm walls, so the guide pipecannot be laid out at the required location. Geodetic methods can directly observe the displacement of thecenter point on the top of the guide pipe with absolute displacement values at high accuracy. Because thedisplacements of observation points are determined at stable benchmarks, these values are considered thepipe's displacement. Thus, an integrated solution allows the center point on the top of the pipe to be theorigin to calculate the displacements of different points located inside the diaphragm wall. Then, thecalculated values are calibrated back to the inclinometer observed values to achieve highly reliabledisplacement, which reflects the moving of diaphragm walls. An experiment integrating the geodetic andgeotechnical methods is conducted with an observation point at a depth of 20 meters at a construction sitein Ho Chi Minh city. The deviations of the top point that are observed by the two methods are -4.37millimeters and -3.69 millimeters on the X-axis and the Y-axis, respectively. The corrected observedresults prove that the integrated solution has a good efficiency in monitoring the horizontal displacementof diaphragm walls. The bottom point observed by an inclinometer is unconfident enough to choose to bea reference point.

Outcomes of Early Surgery in Children under Four Years Old with Large Angle Intermittent Exotropia

Purpose: To find out the significance of early surgery in children of 4 years old and under with large angle intermittent exotropia of 35 prism diopters (PD) and more by examining the results of bilateral lateral rectus recession surgery and factors influencing the surgical outcome.Methods: It was a retrospective study of patients who underwent bilateral lateral rectus muscle recession surgery between 2006 to 2016 with intermittent exotropia greater than or equal to 35 PD and who were able to follow-up for at least 2 years after surgery were divided into two groups based on age of 4 years old. The surgical motor success was defined as exodeviation less than 10 PD, esodeviation less than 8 PD. The angle of deviation, binocular function, best corrected visual acuity, and amount of corrected PD per lateral recession (PD/mm) were compared at each observation point after surgery.Results: The motor success of bilateral rectus muscle recession surgery was 85% in children of age 4 years and under, 65.5% in age over 4 years. Success rate of early surgery was 1.3 times higher in younger age group, but there was no statistical meaning. The complication of surgery after 2 years of follow up was less in younger group-the rate of recurrent exotropia was 15% in younger group, 31.3% in older group and the rate of consecutive esotropia was 0% and 3.1%, respectively. Stereoacuity after 2 years of surgery was not fall behind in younger group compared to older group.Conclusions: It is possible to obtain good surgical results by performing early surgery rather than hesitating to operate due to the younger age in patients younger than 4 years old with large angle exotropia of 35 PD and more for long-term follow up and efficient patient management.

Analysis of air pollution in the City of Odesa using automated observation data

The work presents the analysis of air pollution in the City of Odesa using, among others, the data of automated observations. The air basin state was also evaluated using individual parameters of sustainable development. According to the official data of the recent years the City of Odesa belongs to the most polluted cities of Ukraine in terms of air pollution. Based on the ranking results it was established that the level of atmospheric pollution in the City of Odesa can be classified as high for the most of pollutants. It is classified as acceptable for some substances (sulfur dioxide and nitrogen oxide) and as extremely high for formaldehyde concentration. After comparing the observational data related to content of individual pollutants at the OSENU's observation point and the data of long-term observations in the city it was found that the content of nitrogen dioxide generally corresponds to the average long-term values. The observations conducted at the points of the city network indicated that the content of carbon monoxide is two orders of magnitude lower and the content of PM10 is one order of magnitude lower than dust concentrations. The increased content of certain pollutants in the air (nitrogen dioxide, carbon monoxide, etc.) is observed in the summer-autumn period and caused by the traffic intensification. The evaluation of the city's air basin state using individual parameters of the environmental measurement index showed that we observed better conditions in 2014 and 2016. The conditions for sustainable development are characterized by average indicators, however, towards worsening of the situation. The results obtained in this paper form a basis for extending the implementation of the Resolution of the Cabinet of Ministers of Ukraine on introducing a new procedure for state monitoring of the atmospheric air in Ukraine. The existing laboratory base of the observation points requires radical re-equipment. It is also necessary to conduct an air pollution survey for identification of high priority pollutants and, based thereon, development of monitoring programs with consideration of the necessity for keeping certain impurities under control.

SEISMICITY of the CRIMEAN-BLACK SEA REGION in 2015

In 2015, 58 earthquakes were registered in Crimea in the range of energy classes КП=5.2–10.8. The bulk of the epicenters refers to the Black Sea. The maximum density of epicenters can be traced in Alushta (№ 3) area and in the Kerch-Anapa area (№ 5). Spectral and dynamic parameters of their foci were obtained for 16 events in the region; and for 1 of them a focal mechanism solution was obtained. Seismic processes in the Crimean-Black Sea region were monitored by seven stationary digital seismic stations. In February, the «Tarkhankut» observation point was closed. Representative registration of earthquakes with Кп=9.0 is still provided for main part of the Crimean-Black Sea region. A peculiarity of spatial distribution of earthquakes is the occurrence of two strongest earthquakes in the year under consideration with КП=10.8 in the Kerch-Anapa (№ 5) and Azovo-Kuban (№ 7) areas. The maximum (Кп=10.8, MLWSG=3.8, Mw=3.8) earthquake occurred on August 16 at 22h38m in the Kerch-Anapa region at the depth of h=7 km. This shock caused tremors in Anapa with the intensity of I=2 according the MSK-64 scale. 2015 is characterized by weak seismic activity. The total number of registered earthquakes, ΣN=58, decreased against ΣN=119 in 2014 and is below than the average Nav=69 for the ten-year observation period (2004–2013). The annual seismic energy is ΣE=1.491011J, that is 5.6 times less than the average value ΣEav=8.41011J for the ten-year period. This suggests that we can expect increased seismicity in the region in subsequent years.

Equations of Electrodynamics

Maxwell&rsquo;s equations are valid only for a stationary observation point, therefore, to adequately describe real processes so far we have had to move to a moving reference frame. This paper presents the equations of electrodynamics for the moving observation point, it is shown that plane and spherical electromagnetic waves are their solutions, while the spherical wave propagates only outward, which cannot be said about Maxwell&rsquo;s equations. The fields of uniformly moving charges are also solutions of the equations. Now there is no need to move to a moving reference frame, to use four-dimensional space and covariant form of equations. The question of finding a universal form of the equations that allows a solution in the form of the field of an arbitrarily moving charge remains open. This raises the question of the existence of a two-parameter group of transformations of electromagnetic fields along with the known one-parameter group has been posed. The phenomena derived from the equations, which make an additional contribution to the phase overrun in the Aharonov-Bohm effect are considered. The equation of motion of a charged particle in an electromagnetic field without simplifying approximations is considered, which allows us to take into account the radiation effects. It is shown that the fields in a moving observation point depend on its velocity and acceleration. In particular, although in a constant uniform electric field a force qE acts on a motionless charged particle, but on the same motionless but not fixed particle the force 4/3qE acts already, because it has a nonzero acceleration and the electric field at this point is larger. As the speed increases, the field decreases, and when it reaches the speed of light, when the particle stops accelerating, the force again becomes equal to qE The principle of operation of an unconventional alternator in a constant electric field and its corresponding engine, as well as new types of direct and impulse current generators, predicted by the equations, are described.

Preliminary Study of Probolinggo Active Fault in East Java Based on Gravity Method

The Gravity Method based on TOPEX satellite data is a one of geophysical method which from satellite observations. The gravity method investigate the gravitational field from one to another observation point. The principle of this method has the ability to distinguish the mass material density from its environment, so that the subsurface structure can be identified. In this research, gravity method is used to identify subsurface structures that are suspected of Probolinggo Fault and identify the rock lithology. From TOPEX we get free air anomaly and then applied the correction process to obtain Complete Bouguer Anomaly (CBA) value. The CBA value is processed interpolation to create CBA map, and then the map is filtered by butterworth to obtain regional and residual maps. The value of high gravity acceleration is 0.076 - 19.74 mGal indicating compact rocks. Meanwhile, based on the residual anomaly map, the value of smaller gravity acceleration is -0.92 - 0.9 mGal indicates lower compacting rocks with smaller mass. The gravity acceleration contrast on the residual anomaly, on the north side of fault line (0.12 mGal to 0.45 mGal) and on the south side (-0.92 mGal to -0.043 mGal), is interpreted as normal fault. Furthermore, 3D modelling shows density value less than 2 gr/cm3 we can interpret as pyroclastic fall, in between 2 gr/cm3 until 2.4 gr/cm3 is sandstone and more than 2.4 gr/cm3 is igneous rock such as andesit. 2D slicing modelling show presence the shear fault, so we can suspect this area have oblique fault with west-east direction.