Saulo Siqueira Martins

Saulo Siqueira Martins
Federal University of Pará | UFPA · Faculty of Geophysics

Ph.D. in Geophysics
Professor of Geophysics at Universidade Federal do Pará

About

24
Publications
684
Reads
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20
Citations
Additional affiliations
July 2014 - June 2015
University of Alberta
Position
  • PostDoc Position

Publications

Publications (24)
Article
Full-text available
We have estimated a 1-D permittivity model from a 100m long variable offset GPR in the West Antarctic ice sheet. That model inherits the inaccuracies in depth from the velocity model, which should be corrected before attempting to correlate it with the density log from a close-by borehole. We performed that correction by aligning a synthetic ice de...
Article
Full-text available
This work deals with reconstructing firn layer thicknesses at the deposition time from the firn's observed thickness in ice cores, thus reconstructing the annual accumulation, yielding a timescale and an ice-core chronology. We employed a dynamic time warping algorithm to find an optimal, non-linear alignment between an H2O2 concentration data seri...
Preprint
Full-text available
This work deals with two distinct datasets, a well preserved hydrogen peroxide, H 2 O 2 , concentration data from firn cores at a high deposition location and a temperature time series, estimated from the daily records from four Antarctic stations around the Antarctic Peninsula. With them we have produced a time scale, an ice-core chronology, for t...
Article
Between Marambaia spit and Jacarepagua barrier island system, two major coastal plains in Rio de Janeiro State, Grumari's type of evolution remains unknown, since it was anthropologically modified from the 1960s, where all superficial sedimentary deposits were devastated, intensively changing its natural landscape, and hiding how it has been formed...
Article
We show high quality images of constructed multi-offset radar data along a shore-normal profile on Marambaia Barrier Island. The multi-offset data is constructed assembling traces from seven collinear fixed-offset passes with a 100MHz bistatic equipment. The traces are binned and stacked as sparse 7-trace common-source gathers along the profile. We...
Article
Full-text available
We focus here on three horizons conspicuously embedded in the rich radar stratigraphy revealed on the fixed-offset radar data obtained Plateau Detroit, Antarctic Peninsula. Spatial filtering removed the more energetic reflection field and the surface wave arrivals at the earlier time, leaving only the diffracted field. This is particularly striking...
Article
Ground Penetrating Radar data are often acquired along profiles employing bistatic equipment with a fixed distance between the transmitter (Tx) and receiver (Rx) antennae. Even in cases where more than two antennae are used, the number of channels tends to be relatively small, resulting in either a limited number of offsets or gathers with inadequa...
Conference Paper
In this work, the GPR mono-channel data is acquired in Marambaia barrier island. These data are processed to simulate multi-channels and thus allow the estimation of the 2D velocity model in time of the subsurface area data. The imaging data obtained from these reflectors focused best shown with greater number of refractions being collapsed, when c...
Article
Most of the data acquisition in ground-penetrating radar is done along fixed-offset profiles, in which velocity is known only at isolated points in the survey area, at the locations of variable offset gathers such as a common midpoint. We have constructed sparse, heavily aliased, variable offset gathers from several fixed-offset, collinear, profile...
Conference Paper
Full-text available
This work addresses the almost unavoidable aliasing that lingers on wide-aperture multichannel GPR data. That arises from a practical limitation imposed by the currently available instrumentation. Here we present a feasible methodology in which we assemble a limited number of collinear fixed-offset profiles into sparse end-on gathers followed by tr...
Conference Paper
Full-text available
Traditionally, first-arrival travel-time tomographic problems are treated as nonlinear inverse problems solved by deterministic optimization methods. These methods minimize the objective function by taking its derivatives. In some problems these derivatives are slow to compute and the method becomes inefficient. Another limitation inherent to deter...
Conference Paper
Full-text available
It is well known that a 3-D survey can provide the best visualization of the subsurface. But the common practice in 3-D GPR is very poor in comparison with the corresponding for the land 3-D seismic. The usual deployment of closed-spaced fixed-offset profiles have limited azimuthal information and restricts processing to post-stack. In this paper w...
Poster
Near-Surface Geophysics General Contributions Posters. ’Some examples of EM phase velocity dispersion in near-surface layers’.
Conference Paper
Full-text available
This paper is in Portuguese. Several structures are observed in Paleozoic, Mesozoic, and Cenozoic of Guiana Shield. The structures have a NW-SE trend, representing shear belts. Many of the structures suffered reactivation during those periods. In this study we applied two geophysical methods, gravimetry and ground penetrating radar, in order to und...