Physical Sciences and Mathematics Commons^™

Simulation Of A Salt Dome Using 2d Linear And Nonlinear Inverse Modeling Of Residual Gravity Field Data, Soheyl Pourreza, Farnush Hajizadeh

Bulletin of the Mineral Research and Exploration

In gravity field inversion we usually dealing with underdetermined problems and for obtaining realistic solutions can introduce a depth-weighting function to the inversion algorithm. We employ a linear inversion method for determining the underground density distribution of the gravity causative mass. The validation and accuracy of method is tested on two synthetic gravity anomaly from different models, while the data are noise- free and corrupted with noise. In this paper, We also invert the 2D gravity anomaly produced by a salt dome from the northwest of Iran. The salt domes in the region under investigation are a rich source of …

Earthquake-Rotated Headstones As A Means Of Re-Evaluating Epicentral Location Of The 1944 Massena-Cornwall Earthquake: New York, United States And Ontario, Canada, Sandra L. Walser, Alexander K. Stewart

The Compass: Earth Science Journal of Sigma Gamma Epsilon

The Massena-Cornwall earthquake (September 5th, 1944) is the largest earthquake in New York state history. Two epicenters have been previously proposed (Milne, 1949; Dewey and Gordon, 1984); however, they are separated by 15 km, an error that could associate each proposed epicenter with two different local faults. Due to the lack of standardized seismic-array data, there is value in approaching this event using an unconventional data set. The methodology of MacDonald and Wentworth (1952) was executed through ArcMap 10.5.1 to yield an area most likely to contain the epicenter. One-hundred fifty-four earthquake-rotated headstones from 15 cemeteries within ~35 km of …

Orientation Of Paleostress Of Raplee Ridge Anticline, Loren Randall Holyoak, John S. Maclean

The Compass: Earth Science Journal of Sigma Gamma Epsilon

During the Laramide Orogeny several major folds were formed in Southern Utah, one of those being the Raplee Ridge anticline. Raplee Ridge is approximately eight miles from Mexican Hat, Utah. The San Juan River cuts through the anticline, exposing the Honaker Trail Formation’s beds of shale and limestone with chert nodules. Accompanying the mountain-scale ductile deformation of the Raplee Ridge anticline are decimeter-scale brittle conjugate fractures in the limestone’s chert nodules. The objective of this study is to compare the orientation of paleostress that formed the Raplee Ridge anticline with the conjugate fractures within the chert nodules to see if …

Machine Learning Predicts Aperiodic Laboratory Earthquakes, Olha Tanyuk, Daniel Davieau, Charles South, Daniel W. Engels

SMU Data Science Review

In this paper we find a pattern of aperiodic seismic signals that precede earthquakes at any time in a laboratory earthquake’s cycle using a small window of time. We use a data set that comes from a classic laboratory experiment having several stick-slip displacements (earthquakes), a type of experiment which has been studied as a simulation of seismologic faults for decades. This data exhibits similar behavior to natural earthquakes, so the same approach may work in predicting the timing of them. Here we show that by applying random forest machine learning technique to the acoustic signal emitted by a laboratory …

A Brief Note On The Effects Of Floating Standard Deviation (Non- Derivative) And Horizontal Gradient (Derivative) Filters, Ceyhan Ertan Toker

Bulletin of the Mineral Research and Exploration

When processing gravity data, the filters are used in space and frequency environments. The filters allow more selectable parameter estimations than raw data about the structure being examined. Filtering in a broad sense means monitoring the data under the constraints we want. While the filters allow some information to become more noticeable, they allow some information to be lost or become less noticeable from data. In this case, the losses in the data make the interpretation difficult and can cause errors. Derivative and phase filters provide quantitative information about the variation of data in different directions. The display of the …

Paleoseismological Catalog Of Pre-2012 Trench Studies On The Active Faults In Turkey, Şule Gürboğa, Oktay Gökçe

Bulletin of the Mineral Research and Exploration

Instrumental and historical earthquake catalogues have to be examined and evaluated to understand the long-term seismic behaviour of active faults. Although the instrumental records have been determined from the national and international observatories, the historical seismic catalogues are very limited in Turkey. For the reason, we aimed to compile paleoseismological trench studies carried out before 2012 in the areas of onshore and offshore sections of Turkey. In terms of a Turkey Paleoseismological Project (TURKPAP) posted by General Directorate of Mineral Research and Exploration (MTA) in the 2012 year, a number of paleoseismological investigations have been initiated and documented for archiving …

The Use Of Electromagnetic And Vertical Electrical Sounding Methods In Groundwater Exploration, Hafiz Mohammed Nazi̇fi̇, Levent Gülen

Bulletin of the Mineral Research and Exploration

Electromagnetic (EM) profiling and Vertical Electrical Sounding (VES) studies were carried out for groundwater exploration in the Twifo – Hemang Lower Denkyira Districts of Ghana. These two geophysical methods were used for exploring the groundwater potentials beneath Achiase, Mbaa Mpe Hia Community and Moseaso Community. This paper seeks to encourage the use of inversion for interpreting electromagnetic data rather than the usual qualitative interpretation method using line graphs and also the use of apparent resistivity maps as 2D pseudo resistivity maps to support interpretations of the 1D inversion results (in cases where the available budget could not permit 2D and …

An Approach To Obtain The Structural Information From The Electrical Resistivity Well Logging Curves, Doğan Can Karataş, Emi̇n Uğur Ulugergerli̇, Uğur Zaman

Bulletin of the Mineral Research and Exploration

In well logging measurements, the effect of the fluid in the well on the resistivity log curves and the investigation depth/distance for 16 and 64 inches logs were investigated in two-dimensional numerical modeling with the assumption that underground structures are symmetrical. Structural information was obtained via recovering the real resistivity values by using the inversion rather than empirical approaches. Generally, in the case of using the conductive fluid (1 ohm.m<) depending on the ratio of unit thickness (k) with respect to the length of log (l) (i.e. k/l), the insulating formations produce an “M” shaped signs for k/l<1 and appears as the conductive unit that cause fictitious structures in the data. The depth/distance of the research on the other hand causes deviations in the resistivity of structure due to tool length and distance. By the help of the inversion study one of the possible models is obtained. Contribution of this method to such studies is the reveal of compatibility of the resistivity model and data that usually neglected in other approaches.

https://doi.org/10.19111/bulletinofmre.451546