How Groundwater Extraction & Replenishing Causes Surface Deformation & Subsidence

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Researchers at Caltech made the animations below which show the seasonal deformation and subsidence of Earth’s surface, respectively,  as a result of groundwater extraction and refilling. This occurs when soil and earth layers are compacted and undergo subsidence due to the decrease of upward hydrostatic pressure balancing the weight of the layers.

Surface deformation and subsidence of Earth’s surface is measured using Interferometric Synthetic Aperture Radar (ISAR). ISAR is also used for natural hazard assessment. This includes applications to regions of volcanic, tectonic (e.g. faults and mountains), and construction activities.

 

source: Caltech

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Seeking an PhD or R&D job in Remote Sensing for Geophysics or Oceanography|Cherche une Thèse ou une poste R&D en Télédétection ou Géophysique

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Seeking a PhD or R&D job in Remote Sensing with applications in Geophysics or Oceanography starting from October 2018. Your help is very much appreciated. You can contact me. Thank you

Je cherche une thèse ou une poste R&D en Télédétection avec des applications en Géophysique ou Océanographie a partir d’Octobre’18. Votre aide est très appréciée. Vous pouvez me contacter. Merci

Insight, a mission to explore Mars’ Interior

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So far the only way to get any information about the interior of rocky planets was from the moment of inertia which is related to a planets mass distribution. This only allowed to estimate if a planet has a mantle and what the estimated thicknesses of the core and mantle are. Of course, other (remote sensing) methods like potential (gravity and magnetic) fields can also give more information about a planets interior. However, the only solid way to determine the layer interface and their depth and thicknesses is seismic imaging, a popular technique used to image Earth’s subsurface and interior.

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A Close-up Look at a Rare Underwater Eruption

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via: Woods Hole scientists took close look at largest underwater volcanic eruption in 100 years

Borehole NMR – an MRI for Earth’s subsurface

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source: Borehole Nuclear Magnetic Resonance (NMR): a valuable tool for environmental site management, doi:10.5066/F73J3BW0, USGS

Python wrappers for the Generic Mapping Tools on the way

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An interface for interoperability between the Generic Mapping Tools (GMT), a tool used by geophysicists to create research-quality figures, and Matlab has recently been developed that allows GMT users to interact with Matlab and Matlab users to make use of GMT.

GMT wrappers are currently also being developed for the Python programming language, particularly to be used in the IPython/Jupyter notebook due to an initiative by Leonardo Uieda (and his professor Paul Wessel) whose Postdoc is being funded by the NSF. You can watch his talk at the SciPy 2017 conference below.

Some of the mentioned advantages to which I attest  include:

  • Begin and End statements are introduced to eliminate the need to pipe postscript results into a file in each line of code being written. This also eliminates the need to use the -K and -O flags which keep the file open and updates it, respectively. The -K and -O flags are a major confusion for newcomers to GMT.
  • temporary files are created under the /tmp directory, in Linux, so they will automatically be cleaned once the jupyter notebook is closed or the operating system is rebooted. Moreover, every project will have its own  directory so files from different projects don’t get mixed up.
  • GMT documentation straight in the Jupyter notebook
  • Matplotlib- & Basemap-like behaviour, particularly inline viewing of figures, using gmt.show()
  • Pythonic aliases make the compact GMT flags

To contribute: github.com/GenericMappingTools

Reference

Cook, T. (2017), A powerful new tool for research, Eos, 98, https://doi.org/10.1029/2017EO077489. Published on 17 July 2017.

Converting Greenhouse Gases to Rocks

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One of the ways scientists are attempting to reduce greenhouse gases is to inject these gases into the ground. Specifically, they are testing injecting them, into basalt which is type of igneous rocks usually forming the first (rock) layer (sandwiched between the sedimentary & gabbro layers) in the oceanic crust basalt and in volcanic regions.

The above video features Iceland and its geothermal plants. Iceland is a heaven for geothermal energy as it lies along the Mid-Atlantic Ridge (MAR) (i.e. where Mid-Atlantic ocean floor is spreading apart in opposite directions forming a ridge). Most notably Iceland lies along the V-Shaped Reykjavik ridge (figure below; Google maps) which is part of the Norther MAR.

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