detection of subsurface structures by means of gravity method can be used to determine mass distribution and density contrast of rock units. this distribution could be detected by different geophysical methods, especially gravity method. however, gravity techniques have some drawbacks and can't be always successful in distinguishing subsurface structures. performance of the gravity technique co...

Seismic anisotropy has been widely observed in crust and mantle materials and plays a key role in the understanding of structure and flow patterns. Although seismic anisotropy can be explained by the crystal preferred orientation (CPO) of highly anisotropic minerals in the crust, that is, amphibole, experimental studies on the CPO of amphibole are limited. Here we present the results of novel e...

As oil and gas exploration moves into deeper offshore areas, Shallow Water Flow (SWF) from overpressured, unconsolidated/uncemented sands becomes a high profile drilling hazard. Laboratory measurements show that SWF sands have high seismic compressional to shear velocity (Vp/Vs) ratios. Thus, elastic seismic inversion for Vp/Vs provides a quantitative identification of SWF sands, and predrill p...

We have developed an inversion formulation for velocity and attenuation structure using seismic attributes, including envelope amplitude, instantaneous frequency and arrival times of selected seismic phases. We refer to this approach as AFT inversion for amplitude, (instantaneous) frequency and time. Complex trace analysis is used to extract the different seismic attributes. The instantaneous f...

Attributes remain to be of the utmost importance for the characterization of seismic data. Especially in the scale-range where tuning effects play, the understanding of what is happening, and the subsequent technology to extract the proper attributes from the huge seismic data-volumes remains current. This study starts with the analysis of a set of typical petrophysical log shapes. These log sh...

The authors are to be congratulated for a systematic investigation of the accurate and non subjective classifying approach in seismic research. The authors have conducted several clustering algorithms to the seismic event records from Volcanological and Seismological Observatory at Manizales. Their objective was to improve the grouping of seismic data (i.e., volcano-tectonic earthquakes, long-p...

Seismic interpretation has been traditionally based on reflections or amplitudes. However, amplitude alone can also disguise the true nature of subsurface geology and blur stratigraphic boundaries. In many cases important information is carried by singularities that are not necessarily associated to certain amplitude patterns. We present Hölder exponent (α) as a new seismic attribute which capt...

In order to mitigate against possible impacts of seismic surveys on baleen whales it is important to know as much as possible about the presence of whales within the vicinity of seismic operations. This study expands on previous work that analyzes single seismic streamer data to locate nearby calling baleen whales with a grid search method that utilizes the propagation angles and relative arriv...