Summary

The quality of seismic images varies with several parameters. Fundamentally, the signal strength plays a major role in the clarity of seismic images. By analyzing the signal quality quantitatively as opposed to qualitatively, we can correct the loss of signal strength over a distance and time. The Q factor is a mathematical representation of signal degeneration. It can be used to evaluate the original seismic wavelet from a distorted wavelet. There are several methods to derive the value of Q. But currently, there is no consensus among the geophysicists on which method is more accurate. In this particular study (Lupiancci, Andriano, Oliveira, 2015), researchers evaluated three methods; amplitude decay versus time decay, spectral ratio-based, and Wang’s method. After several iterations of the data, they found the Wang method to be more accurate and provided the most consistent dataset. However, it should be highlighted the spectral ratio-based method also provided very accurate results.

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Abstract

The Late Heavy Bombardment (LHB) is a hypothetical astrophysical event which occurred in our Solar System 4.1 to 3.8 billion years ago. At this time, an increased flux of impacting materials hit the Earth, Moon and other terrestrial planets of the inner Solar System. This has been suggested as the source for the increased number of crater impacts seen on the lunar surface, Venus, and Mars, and inferred to have struck all the inner terrestrial planets; preserved evidence has yet to be discovered on Earth. Several theories have been proposed to explain the crater formations, however the focus will be on the two most accepted theories: the Nice Model and Planet V Hypothesis. The preservation of craters from the LHB is best seen on the Moon due to the lack of plate tectonics, minimal erosion and deposition. Analyzing the surface of the Moon can help us understand the impact that the LHB had on the inner solar system. A lunar timescale is currently being modified, and when calibrated with radiometric dates from Martian samples, a timescale for Mars and other planetary bodies could be developed to verify if the LHB was a synchronous event. The LHB was early in Earth’s evolution and the contribution of extraterrestrial material to the planet is thought to have affected it in different ways; this includes the development of the atmosphere, biosphere and hydrosphere. The LHB is important not only to explain the sudden increase in crater evidence but also to help confirm the current geochemical properties of the terrestrial planetary system as seen today.

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Thin section sketches are drawings that represent what you observed. But most of us (students, researchers and professors) are not artistically inclined. Even if you are good at drawing diagrams, you still have to empathize key features when drawing a thin section sketch. Here are some tips and tricks for making a good (if not perfect) thin section sketch.