Geophysics, Python and More…
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Create Globes with Basemap and Cartopy
In this short post, I am showing how to create maps in the orthographic projection, which, to most of us, corresponds to the globe as seen from outer space. As usual, the code and some additional examples are available in a jupyter notebook in the interpies repository. Python libraries for plotting 2D data on maps […]
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Colormaps and Colorbars
Every now and then, the geophysics community debates furiously about which colormap is best to display geophysical data. This is not a new issue and the starting point for this discussion seems to be roughly 1996 when Rogowitz and Treinish started to question the use of rainbow-like colormaps for scientific visualisation. Despite its obvious flaws, the […]
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How to Load Sandwell & Smith Gravity Data in Python?
Introduction Mapping the depth of the oceans globally was one of the greatest successes of geophysics in the 20th century. Without bathymetry, we would not know the locations of mid-ocean ridges, volcanic seamounts, and transform faults, to name a few, all of which are key elements of plate tectonics. But mapping the seafloor is hard, […]
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Three notebooks to jump start a data science project
Introduction I was in Paris last week for the 2017 Subsurface Hackathon. It was superbly organised by Agile Scientific and Total. Together, they managed to draw a large (about 60 persons) and diverse crowd to participate to the challenge of producing some working and usable software in only two days. The event took place over […]
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How to add cross-sections to OpendTect?
Introduction This post is associated with a Jupyter notebook available on GitHub. In a previous post, I explained how to add colour maps to the 3D environment of OpendTect. The method is simply to convert the RGB image of the map into an indexed colour image. The resulting grid can be loaded as any other horizon […]
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How to add maps to OpendTect?
Introduction This post is associated with a couple of Jupyter notebooks available on GitHub. OpendTect is a great piece of software that allows you to load, process and interpret seismic data. In OpendTect, 2D lines and 3D volumes are displayed in a nice 3D environment that is easy to manipulate. Horizons, either 2D (lines) or 3D […]
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Hillshading with matplotlib
Summary Hillshading simulates the variable illumination of a surface by a directional light source. It is a great method to represent relief on a map and it works very well with potential field data too, not only with topographic data. Creating shaded maps in Python with matplotlib is easy and a few examples are provided here. However, a simple transparency […]
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Histogram Equalization in Python and matplotlib
Summary When displaying geophysical data in a map, one may find it difficult to show both the presence of extremes and the subtle variations in the background signal. Histogram equalization is there to help, as it redistributes intensities and increases the contrast. In this new implementation for Python and matplotlib, the equalization is applied to the colormap rather than […]
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Basic statistics with Parkrun data
Summary This post might not have much to do with geophysics but it is another way to share information and ideas about my interests. I am comparing in a basic and simple way the results of a 5 km run at several locations in and around Leeds. In the process, I have learnt a couple of things about […]
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Manipulate SEGY files with segy2segy
Working with seismic data is great but sometimes technical issues such as loading and converting files come in the way of the more interesting part of the job. One of the most common problems I have encountered in my career is the mismatch between the coordinate system of seismic data and the coordinate system of the […]