42

If we consider only the magnetic field generated by natural sources, and not the ones generated by human activities. The general trend is that higher intensities of the magnetic field happen close to the magnetic poles. However, this is just a general trend. The southern hemisphere experiences the highest magnetic fields intensities, reaching over 65,000 nT, ...


19

The record the article is referring about seems to be the same as registered at Guiness World Records: On 13 September 2012 the World Meteorological Organisation disqualified the record for the highest recorded temperature, exactly 90 years after it had been established at El Azizia, Libya, with a measurement of 58°C. The official highest recorded ...


13

Since it is not specified in the question (and to complement the other answer), the strongest magnetic fields on Earth are not naturally generated, but artificially. The current world record holder seems to be the National High Magnetic Field Laboratory (NHMFL) in Los Alamos, USA, with a magnetic field strength of about 100T (so about two million times ...


10

I'm the scientist in the article; someone just saw this question and emailed me about it! (I'm on as a guest here since I don't have an account, so you'll hopefully trust it's me. Even if you don't believe it's me, I hope the answer will still be useful.) It's entirely a safety issue. The best way to get around on the surface of the glaciers in this area is ...


5

Short answer: the refraction of light is ultimately dependent on both temperature and exact composition of the medium (e.g., liquid water or ice) through which it passes. Note: strictly speaking, "steam" typically refers to water vapor at temperatures above the boiling point, but in casual usage (and for the purposes of this answer) it is commonly used to ...


5

The Hadean era covers the time from the formation of the Earth until 4bn years ago. It was characterized by a surface of molten rock, due to repeated meteor strikes, volcanism and radioactive decay. "Liquid water oceans existed despite the surface temperature of 230 °C (446 °F) because of the atmospheric pressure of the heavy carbon dioxide atmosphere....


4

In other words where might be a natural place on Earth that would over power a compass and then some Just about anywhere where the rocks are rich in iron. This would occur near iron ore, basalt, gabbro, and similar iron-rich rocks. You really don't need a lot of magnetite in the rock for this to move the compass needle. You don't even need magnetite - ...


4

The wikipedia article List of weather records explicitly states This list does not include remotely sensed observations such as satellite measurements, since those values are not considered official records.[1] Reference 1 in that article, a web archive link to a page on World Meteorological Organization Global Weather & Climate Extremes, adds that (...


4

Are there "transparent" clouds? Yes. One type is called subvisible cirrus clouds. They're essentially clouds that are very, very thin. According to Reverdy et al. (2012): Spaceborne lidar observations have recently revealed a previously undetected significant population of Subvisible Cirrus (SVC). We show them to be colder than −74 °, with an optical ...


4

Tiltmeters placed on the flanks of an active volcano can measure changes in the slope angle of the flank. These changes are often inferred to be related to changes in the shape and activity of the magma chamber. This article provides a quick and dirty example of how these instruments can be used, as well as their limitations. In this case, the tiltmeters ...


4

SEG-D is a specialized format, while SEG-Y is a general-purpose format. In general, SEG-D is intended for field recordings of seismic data, and SEG-Y is intended for 'seismic data exchange'. Having said this, SEG-Y is so general-purpose, and so ubiquitous, that I'm not surprised to hear (anecdotally) that people are using it for data acquisition. Certainly, ...


3

The drag coefficient varies with Reynolds number and hence with wind speed. Most fluid-dynamics textbooks have a graph of the drag coefficient of a sphere versus Reynolds number. Hopefully that could help. (A sphere such as a ping-pong ball is the best shape since its shape is the same in all orientations --- only a sphere has complete omnidirectional ...


2

Yes it is used and it works. I've heard varying viewpoints on it's accuracy and dependability though. I remember my earth science lecturers were in three camps with it: one felt that the dates weren't consistently reliable, the data he'd gotten from astro-dating in the past had very poor independent confidence margins when there was no radiometric ...


2

Try the long game: Start reading up on the research that is being done. For the interesting ones, start corresponding with the authors asking questions about the work. They have to be good questions, showing that you know what you are talking about. Look at who funds each researcher. Check the papers for those 'thank-yous' that give credit to various ...


2

Land that has been heavily disturbed by humans in most developed countries, such as urban and rural regions will have been surveyed for topographical & sub-division purposes. Such data allows for a digital terrain model (DTM) to be created for such regions. When subsidence occurs, the subsided area can be resurveyed & compared to the original DTM to ...


1

Several methods are employed to measure ground subsidence: Spirit leveling, GPS (GNSS), Remote Sensing, Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging to name a few. In the case of modeling subsidence caused by water and oil extraction, the most common measuring methods seem to be Spirit leveling, GPS and Remote Sensing (Interferometric ...


1

As described in the question there are two similar coils, one radiates the AC magnetic field ("transmitter") and the other picks up the weak radiated AC magnetic field produced by subsurface electrical currents induced by the primary field. Sensitivity vs. Depth There are two modes of operation. The following two figures are from Section 4.1 of GEONICS ...


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