7 ms·

Earthquake in Japan yesterday may have shifted land 1.3 meters

119 points by ronyclau 3y ago

sandworm101 3y ago
The amount of energy released in such events boggles the mind. Shifting cubic-kilometers of rock, in this case several hundred or even thousands of cubic-kilometers, even a few inches requires more energy than all the worlds nukes many times over. We live atop an immense heat engine, every little vibration of which could power our entire civilization for years.
- cm2187 3y ago
  It's even harder than harvesting lightnings.
  - sandworm101 3y ago
    I'm not sure about that. Drill some holes, pump some water, and geothermal power straight to the grid can be done. Harvesting lighting would require innumerable towers and even would require some trickery to get it hooked up to our power grids.
    - borgunit2 3y ago
      That’s not kinetic earthquake energy, though. I think in an apples-to-apples comparison, you would need to attach some kind of device to absorb the kinetic energy from the fault.
      - rzzzt 3y ago
        A building-sized piezo crystal?
        lawlessone 3y ago
        Country sized.
    - squirtle24 3y ago
      Or one clock tower and a flux capacitor...
    - cm2187 3y ago
      ...and wait for the next major earthquake to even test it.
  - barbariangrunge 3y ago
    A friend, back when he was a physics student, looked into harvesting lightning. He calculated that it wasn't economically viable: tons of wattage, but for such brief timespans, that it doesn't actually amount to that much on a comparative scale. The cost of building the collectors and transporting the electricity (from ocean platforms) was much higher than the cost of using other energy sources. Iirc. It wasn't exactly a serious investigation by a team of engineers, but I basically trust his conclusion. Maybe it will be more attractive in the future after we stop using hydrocarbons?
    - kulahan 3y ago
      I know embarrassingly little about electricity, but wouldn't this also likely require significant advances in semiconductors to even be feasible?
  - manarth 3y ago
    For starters, the scythe keeps melting
- IKantRead 3y ago
  I've always found it fascinating that geophysicist and earlier advocate for Bayesian methods, Sir Harold Jeffreys, didn't believe in continental drift and plate tectonics because he felt there was no known source of energy on the Earth massive enough to explain this movement. [0] He remained an opponent until death (at which point continental drift was widely accepted) which is both a testament to the literally unbelievable energy behind seismic activity and the importance of updating your Bayesian priors as you gain new information. 0. https://en.wikipedia.org/wiki/Harold_Jeffreys#Opposition_to_continental_drift_and_plate_tectonics https://en.wikipedia.org/wiki/Harold_Jeffreys#Opposition_to_...
  - thehours 3y ago
    Actually the lesson I take away is the importance of not having a 0% (or 100%) prior, since it leaves no room to update with new information.
    - roenxi 3y ago
      It is also suspicious because it means someone has assigned a 0% prior to their being insane or in some sort of Plato's-cave scenario - which is hard to justify. The minimum possible Baysian prior is a base rate of "my senses are just not picking up reality and/or my memory is catastrophically compromised and/or I cannot process logic right now due to some reason" which while low is never going to be 0%. There are too many known ways for human brains to fall over. 0% priors are unjustifiable.
  - throwup238 3y ago
    Another great illustration of Planck’s law: > Max Planck, surveying his own career in his Scientific Autobiography, sadly remarked that “a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.“ -The Structure of Scientific Revolutions
    - blackbear_ 3y ago
- barbariangrunge 3y ago
  I think we sort of have the tech to use geological energy, but I imagine the hardest part is not having your equipment destroyed all the time by quakes? You'd probably want to put your collectors deep underground where there's more activity
  - sandworm101 3y ago
    At a theoretical level, it could be done with ropes. You don't need to wait for earthquakes. Setup two anchors on either side of a fault. String ropes between them. As the two plates slowly more, the stretching ropes can be tied to generators. Totally theoretical but, no new physics is required to extract energy from two slowly moving things.
throw0101d 3y ago
Australia updated its latitude and longitude somewhat recently because of continental drift: > The Geocentric Datum of Australia, the country’s local coordinate system, was last updated in 1994, and Australia is now about 1.5m further north-north-east (or, to give the metric used in a BBC infographic: about the height of a kangaroo). * https://www.theguardian.com/science/2016/aug/03/mind-the-gap-australias-latitude-and-longitude-to-shift-2m-next-year https://www.theguardian.com/science/2016/aug/03/mind-the-gap... * https://www.ga.gov.au/scientific-topics/positioning-navigation/geodesy/datums-projections/gda2020 https://www.ga.gov.au/scientific-topics/positioning-navigati... * https://www.australiangeographic.com.au/topics/science-environment/2017/02/how-gps-keeps-up-with-australias-continental-drift/ https://www.australiangeographic.com.au/topics/science-envir... To anyone working in the GIS industry: how would one go about doing a 'mass update' of locations of an entire country in maps and firmware and such?
- dboreham 3y ago
  Locations inside a country (e.g. plat map boundaries) don't use latitude/longitude.
  - taeric 3y ago
    They didn't used to. And, of course you are correct that survey markers are to landmarks. But, more and more people are using data from online mapping services, that largely think they can store locations in lat/lng. People seem to trust that as "the UTC of location data." That said, those can be just as fraught, no? Since movement will not be fully uniform for the entire continent? And landmarks aren't static things, either? I'm curious how landmarks are done to preserve this, long term?
    - tmm 3y ago
      > And landmarks aren't static things, either? I'm curious how landmarks are done to preserve this, long term? At least in the US, the people in charge of this (the National Geodetic Survey) take movement into account. This[1] is the datasheet for the reference monument nearest my house. It has data for 3D velocity of the reference point. VX = -0.0150 m/yr northward = 0.0040 m/yr VY = -0.0008 m/yr eastward = -0.0148 m/yr VZ = 0.0030 m/yr upward = -0.0002 m/yr I'm not sure what the difference is between VX/VY/VZ and northward/eastward/upward, but those numbers are bigger than I thought they'd be. 15 mm/yr seems like a lot! The official coordinates get updated from time to time, and in-between, perhaps you're supposed to adjust your measurements using that movement data (IANAS)? If there is a significant measured change in location due to an earthquake, I'm sure that data would be included in the monument datasheet or a new set of coordinates would be published. FWIW, I went looking to see when the last earthquake was here in Maryland and it turns out there was one today[2]. [1] https://www.ngs.noaa.gov/cgi-cors/CorsSidebarSelect.prl?site=baco&option=Coordinates14 https://www.ngs.noaa.gov/cgi-cors/CorsSidebarSelect.prl?site... [2] https://www.abc27.com/news/top-stories/2-3-magnitude-earthquake-shakes-portion-of-maryland/ https://www.abc27.com/news/top-stories/2-3-magnitude-earthqu...
badcppdev 3y ago
This is a very sad example of land movement and it's a tragedy that people have died in the aftermath and recovery effort. But it's also an important reminder that our super accurate GPS measurements are not 100% reliable over time. The earth moves. Either in jumps like this or fairly constantly if it's somewhere like Australia [0] 0 -https://www.nytimes.com/2016/09/24/world/what-in-the-world/australia-continental-drift-location-gps.html https://www.nytimes.com/2016/09/24/world/what-in-the-world/a...
- dataflow 3y ago
  I'm confused, how does moving 2.7 inches a year translate into 656 feet over 25 years? Was it moving tens or hundreds of times faster a few decades ago?
  - badcppdev 3y ago
    I assume that should be 6.56 feet or some similar miscalculation converting from metric to imperial measurements
    - throw0101d 3y ago
      > 6.56 feet Statute feet or survey feet? * https://www.nist.gov/pml/us-surveyfoot https://www.nist.gov/pml/us-surveyfoot * https://oceanservice.noaa.gov/geodesy/international-foot.html https://oceanservice.noaa.gov/geodesy/international-foot.htm... * https://en.wikipedia.org/wiki/Foot_(unit)#U.S._survey_foot https://en.wikipedia.org/wiki/Foot_(unit)#U.S._survey_foot
      - manarth 3y ago
        Or Swedish feet (29.69 cm), perhaps an Amsterdam foot (28.3133 cm)? Perhaps make it half and half (and undocumented) so that neighbours can embark on generational land feuds. https://en.wikipedia.org/wiki/Swedish_units_of_measurement#Old_length_units https://en.wikipedia.org/wiki/Swedish_units_of_measurement#O... https://en.wikipedia.org/wiki/Dutch_units_of_measurement#Voet https://en.wikipedia.org/wiki/Dutch_units_of_measurement#Voe...
philip1209 3y ago
How property rights work when land shifts?
- intrasight 3y ago
  Land could grow or shrink. I'd think split the difference.
- falcolas 3y ago
  As I understand it (at least in the US), your land rights are based off of relative measurements from a static (to the land) point. They often look like medallions on the ground, anchored in place by fairly sizable stakes to ensure they don't easily move. The positions of those medallions... not as sure, but I imagine they are in turn positioned according to other static points. If the land cracks, well, I have no idea. That would be a legal battle no doubt. EDIT: These fixed points are called "common points" or "points of beginning (POB)", and there's usually one per neighborhood. There are also apparently buried iron rods (survey pins) that define property lines that can be found using a metal detector or such, but they are not foolproof.
  - Symbiote 3y ago
    The more common points are called trigonometrical points or triangulation stations. https://en.wikipedia.org/wiki/Triangulation_station https://en.wikipedia.org/wiki/Triangulation_station https://en.wikipedia.org/wiki/Point_of_beginning https://en.wikipedia.org/wiki/Point_of_beginning (I'm surprised there's no link between these two articles.) https://en.wikipedia.org/wiki/Initial_point https://en.wikipedia.org/wiki/Initial_point
  - foobarian 3y ago
    Reminds me of this marker story: "Belgian farmer accidentally moves French border" [1] [1] https://www.bbc.com/news/world-europe-56978344 https://www.bbc.com/news/world-europe-56978344
- rwmj 3y ago
  In Japan property boundaries are (often) marked with physical markers embedded into the ground: https://www.japantimes.co.jp/community/2015/01/02/how-tos/property-borders-where-to-draw-the-line/ https://www.japantimes.co.jp/community/2015/01/02/how-tos/pr... https://japanpropertycentral.com/real-estate-faq/land-boundary-surveys/ https://japanpropertycentral.com/real-estate-faq/land-bounda...
dang 3y ago
Related: Magnitude 7.6 earthquake strikes Japan, tsunami warning issued for Ishikawa - https://news.ycombinator.com/item?id=38830281 https://news.ycombinator.com/item?id=38830281 - Jan 2024 (64 comments)
aptitude_moo 3y ago
Obligatory XKCD: https://xkcd.com/2029/ https://xkcd.com/2029/
baron816 3y ago
xkcd’s what if had a video about the earthquake scale last month that was interesting https://youtu.be/e3uk7jU3RHo?si=RULnWlFTqUMqgWZe https://youtu.be/e3uk7jU3RHo?si=RULnWlFTqUMqgWZe
1letterunixname 3y ago
4' in Freedom Units. I'm wondering how well utilities and megastructures on the Noto Peninsula are able to cope with gradual and sudden shifts, even in Japan where earthquakes are assumed. It looks like Noto is being ripped and stretched NW from the mainland. --- Also, I re-read the Fukushima Daiichi report summaries yesterday. It's an almost universal human condition that plays out again and again: corporate risk management for large projects is done improperly, especially when there are constraints and cognitive dissonance imposed by the business culture, and it leads to a major failure. Points of the failure chain include: - Failure to account for known unknown risks such as the land subsidence combined with a large tsunami (based on the coastal geomorphology of the specific site). - Failure to protect critical EDGs from flooding, e.g., seawater intrusion. If trying to run a diesel motor near the ocean, it must be buttoned-up tighter than a Jeep with a snorkel including waterproofing sensors, wiring, and control systems. In general, sites should be chosen on very high ground with a large safety factor. If that's not possible, they should be placed on elevated, reinforced structures. - GE BWR-3/-4 (Mark I) core design is such that they can overheat and self-destruct, even if scrammed, because cooling is an absolute requirement at all times. - A lack of redundant, auxiliary, passive cooling ability, such as a gravity-fed reservoir that can be operated manually. - Regulators did insufficient due-diligence to prevent these risks. - "Made in Japan" failure of culture (this was part of the final report). - Using radionuclides that are inherently dangerous and produce forever waste rather than cheaper alternatives like solar with PES. Japan's solar just overtook nuclear, but still relies heavily on coal and gas. BWRs are inherently nastier than PWRs. Non-problems at FD: - Scramming worked properly, but the primary loops were still hot. Disclaimer: Worked in the nuclear industry where hostnames were Simpsons' character names.
shagie 3y ago
Out There Learning - The Greatest Ever On-Land Fault Movement - https://youtu.be/LUsIIJwxPYU https://youtu.be/LUsIIJwxPYU (length: 4m 25s) > Where is the world's greatest known on-land fault movement of any individual earthquake? It's at a place called Pigeon Bush near Wellington New Zealand. It is the surface trace of the Wairarapa Fault. In 1855 a magnitude 8.2 earthquake offset a small stream bed by about 18.5 metres which is the greatest single-event fault movement of any on-land fault in the globe!
londons_explore 3y ago
Can this be measured using optical flow of satellite images? Optical flow can easily measure displacements far smaller than 1 pixel over a large area.

119 points by ronyclau 3y ago

The amount of energy released in such events boggles the mind. Shifting cubic-kilometers of rock, in this case several hundred or even thousands of cubic-kilometers, even a few inches requires more energy than all the worlds nukes many times over. We live atop an immense heat engine, every little vibration of which could power our entire civilization for years.

cm2187 3y ago
It's even harder than harvesting lightnings.
- sandworm101 3y ago
  I'm not sure about that. Drill some holes, pump some water, and geothermal power straight to the grid can be done. Harvesting lighting would require innumerable towers and even would require some trickery to get it hooked up to our power grids.
  - borgunit2 3y ago
    That’s not kinetic earthquake energy, though. I think in an apples-to-apples comparison, you would need to attach some kind of device to absorb the kinetic energy from the fault.
    - rzzzt 3y ago
      A building-sized piezo crystal?
      - lawlessone 3y ago
        Country sized.
  - squirtle24 3y ago
    Or one clock tower and a flux capacitor...
  - cm2187 3y ago
    ...and wait for the next major earthquake to even test it.
- barbariangrunge 3y ago
  A friend, back when he was a physics student, looked into harvesting lightning. He calculated that it wasn't economically viable: tons of wattage, but for such brief timespans, that it doesn't actually amount to that much on a comparative scale. The cost of building the collectors and transporting the electricity (from ocean platforms) was much higher than the cost of using other energy sources. Iirc. It wasn't exactly a serious investigation by a team of engineers, but I basically trust his conclusion. Maybe it will be more attractive in the future after we stop using hydrocarbons?
  - kulahan 3y ago
    I know embarrassingly little about electricity, but wouldn't this also likely require significant advances in semiconductors to even be feasible?
- manarth 3y ago
  For starters, the scythe keeps melting
IKantRead 3y ago
I've always found it fascinating that geophysicist and earlier advocate for Bayesian methods, Sir Harold Jeffreys, didn't believe in continental drift and plate tectonics because he felt there was no known source of energy on the Earth massive enough to explain this movement. [0] He remained an opponent until death (at which point continental drift was widely accepted) which is both a testament to the literally unbelievable energy behind seismic activity and the importance of updating your Bayesian priors as you gain new information. 0. https://en.wikipedia.org/wiki/Harold_Jeffreys#Opposition_to_continental_drift_and_plate_tectonics https://en.wikipedia.org/wiki/Harold_Jeffreys#Opposition_to_...
- thehours 3y ago
  Actually the lesson I take away is the importance of not having a 0% (or 100%) prior, since it leaves no room to update with new information.
  - roenxi 3y ago
    It is also suspicious because it means someone has assigned a 0% prior to their being insane or in some sort of Plato's-cave scenario - which is hard to justify. The minimum possible Baysian prior is a base rate of "my senses are just not picking up reality and/or my memory is catastrophically compromised and/or I cannot process logic right now due to some reason" which while low is never going to be 0%. There are too many known ways for human brains to fall over. 0% priors are unjustifiable.
- throwup238 3y ago
  Another great illustration of Planck’s law: > Max Planck, surveying his own career in his Scientific Autobiography, sadly remarked that “a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.“ -The Structure of Scientific Revolutions
  - blackbear_ 3y ago
barbariangrunge 3y ago
I think we sort of have the tech to use geological energy, but I imagine the hardest part is not having your equipment destroyed all the time by quakes? You'd probably want to put your collectors deep underground where there's more activity
- sandworm101 3y ago
  At a theoretical level, it could be done with ropes. You don't need to wait for earthquakes. Setup two anchors on either side of a fault. String ropes between them. As the two plates slowly more, the stretching ropes can be tied to generators. Totally theoretical but, no new physics is required to extract energy from two slowly moving things.

throw0101d 3y ago

Australia updated its latitude and longitude somewhat recently because of continental drift: > The Geocentric Datum of Australia, the country’s local coordinate system, was last updated in 1994, and Australia is now about 1.5m further north-north-east (or, to give the metric used in a BBC infographic: about the height of a kangaroo). * https://www.theguardian.com/science/2016/aug/03/mind-the-gap-australias-latitude-and-longitude-to-shift-2m-next-year https://www.theguardian.com/science/2016/aug/03/mind-the-gap... * https://www.ga.gov.au/scientific-topics/positioning-navigation/geodesy/datums-projections/gda2020 https://www.ga.gov.au/scientific-topics/positioning-navigati... * https://www.australiangeographic.com.au/topics/science-environment/2017/02/how-gps-keeps-up-with-australias-continental-drift/ https://www.australiangeographic.com.au/topics/science-envir... To anyone working in the GIS industry: how would one go about doing a 'mass update' of locations of an entire country in maps and firmware and such?

dboreham 3y ago
Locations inside a country (e.g. plat map boundaries) don't use latitude/longitude.
- taeric 3y ago
  They didn't used to. And, of course you are correct that survey markers are to landmarks. But, more and more people are using data from online mapping services, that largely think they can store locations in lat/lng. People seem to trust that as "the UTC of location data." That said, those can be just as fraught, no? Since movement will not be fully uniform for the entire continent? And landmarks aren't static things, either? I'm curious how landmarks are done to preserve this, long term?
  - tmm 3y ago
    > And landmarks aren't static things, either? I'm curious how landmarks are done to preserve this, long term? At least in the US, the people in charge of this (the National Geodetic Survey) take movement into account. This[1] is the datasheet for the reference monument nearest my house. It has data for 3D velocity of the reference point. VX = -0.0150 m/yr northward = 0.0040 m/yr VY = -0.0008 m/yr eastward = -0.0148 m/yr VZ = 0.0030 m/yr upward = -0.0002 m/yr I'm not sure what the difference is between VX/VY/VZ and northward/eastward/upward, but those numbers are bigger than I thought they'd be. 15 mm/yr seems like a lot! The official coordinates get updated from time to time, and in-between, perhaps you're supposed to adjust your measurements using that movement data (IANAS)? If there is a significant measured change in location due to an earthquake, I'm sure that data would be included in the monument datasheet or a new set of coordinates would be published. FWIW, I went looking to see when the last earthquake was here in Maryland and it turns out there was one today[2]. [1] https://www.ngs.noaa.gov/cgi-cors/CorsSidebarSelect.prl?site=baco&option=Coordinates14 https://www.ngs.noaa.gov/cgi-cors/CorsSidebarSelect.prl?site... [2] https://www.abc27.com/news/top-stories/2-3-magnitude-earthquake-shakes-portion-of-maryland/ https://www.abc27.com/news/top-stories/2-3-magnitude-earthqu...

badcppdev 3y ago

This is a very sad example of land movement and it's a tragedy that people have died in the aftermath and recovery effort. But it's also an important reminder that our super accurate GPS measurements are not 100% reliable over time. The earth moves. Either in jumps like this or fairly constantly if it's somewhere like Australia [0] 0 -https://www.nytimes.com/2016/09/24/world/what-in-the-world/australia-continental-drift-location-gps.html https://www.nytimes.com/2016/09/24/world/what-in-the-world/a...

dataflow 3y ago
I'm confused, how does moving 2.7 inches a year translate into 656 feet over 25 years? Was it moving tens or hundreds of times faster a few decades ago?
- badcppdev 3y ago
  I assume that should be 6.56 feet or some similar miscalculation converting from metric to imperial measurements
  - throw0101d 3y ago
    > 6.56 feet Statute feet or survey feet? * https://www.nist.gov/pml/us-surveyfoot https://www.nist.gov/pml/us-surveyfoot * https://oceanservice.noaa.gov/geodesy/international-foot.html https://oceanservice.noaa.gov/geodesy/international-foot.htm... * https://en.wikipedia.org/wiki/Foot_(unit)#U.S._survey_foot https://en.wikipedia.org/wiki/Foot_(unit)#U.S._survey_foot
    - manarth 3y ago
      Or Swedish feet (29.69 cm), perhaps an Amsterdam foot (28.3133 cm)? Perhaps make it half and half (and undocumented) so that neighbours can embark on generational land feuds. https://en.wikipedia.org/wiki/Swedish_units_of_measurement#Old_length_units https://en.wikipedia.org/wiki/Swedish_units_of_measurement#O... https://en.wikipedia.org/wiki/Dutch_units_of_measurement#Voet https://en.wikipedia.org/wiki/Dutch_units_of_measurement#Voe...

philip1209 3y ago

How property rights work when land shifts?

intrasight 3y ago
Land could grow or shrink. I'd think split the difference.
falcolas 3y ago
As I understand it (at least in the US), your land rights are based off of relative measurements from a static (to the land) point. They often look like medallions on the ground, anchored in place by fairly sizable stakes to ensure they don't easily move. The positions of those medallions... not as sure, but I imagine they are in turn positioned according to other static points. If the land cracks, well, I have no idea. That would be a legal battle no doubt. EDIT: These fixed points are called "common points" or "points of beginning (POB)", and there's usually one per neighborhood. There are also apparently buried iron rods (survey pins) that define property lines that can be found using a metal detector or such, but they are not foolproof.
- Symbiote 3y ago
  The more common points are called trigonometrical points or triangulation stations. https://en.wikipedia.org/wiki/Triangulation_station https://en.wikipedia.org/wiki/Triangulation_station https://en.wikipedia.org/wiki/Point_of_beginning https://en.wikipedia.org/wiki/Point_of_beginning (I'm surprised there's no link between these two articles.) https://en.wikipedia.org/wiki/Initial_point https://en.wikipedia.org/wiki/Initial_point
- foobarian 3y ago
  Reminds me of this marker story: "Belgian farmer accidentally moves French border" [1] [1] https://www.bbc.com/news/world-europe-56978344 https://www.bbc.com/news/world-europe-56978344
rwmj 3y ago
In Japan property boundaries are (often) marked with physical markers embedded into the ground: https://www.japantimes.co.jp/community/2015/01/02/how-tos/property-borders-where-to-draw-the-line/ https://www.japantimes.co.jp/community/2015/01/02/how-tos/pr... https://japanpropertycentral.com/real-estate-faq/land-boundary-surveys/ https://japanpropertycentral.com/real-estate-faq/land-bounda...

dang 3y ago

Related: Magnitude 7.6 earthquake strikes Japan, tsunami warning issued for Ishikawa - https://news.ycombinator.com/item?id=38830281 https://news.ycombinator.com/item?id=38830281 - Jan 2024 (64 comments)

aptitude_moo 3y ago

Obligatory XKCD: https://xkcd.com/2029/ https://xkcd.com/2029/

baron816 3y ago

xkcd’s what if had a video about the earthquake scale last month that was interesting https://youtu.be/e3uk7jU3RHo?si=RULnWlFTqUMqgWZe https://youtu.be/e3uk7jU3RHo?si=RULnWlFTqUMqgWZe

1letterunixname 3y ago

4' in Freedom Units. I'm wondering how well utilities and megastructures on the Noto Peninsula are able to cope with gradual and sudden shifts, even in Japan where earthquakes are assumed. It looks like Noto is being ripped and stretched NW from the mainland. --- Also, I re-read the Fukushima Daiichi report summaries yesterday. It's an almost universal human condition that plays out again and again: corporate risk management for large projects is done improperly, especially when there are constraints and cognitive dissonance imposed by the business culture, and it leads to a major failure. Points of the failure chain include: - Failure to account for known unknown risks such as the land subsidence combined with a large tsunami (based on the coastal geomorphology of the specific site). - Failure to protect critical EDGs from flooding, e.g., seawater intrusion. If trying to run a diesel motor near the ocean, it must be buttoned-up tighter than a Jeep with a snorkel including waterproofing sensors, wiring, and control systems. In general, sites should be chosen on very high ground with a large safety factor. If that's not possible, they should be placed on elevated, reinforced structures. - GE BWR-3/-4 (Mark I) core design is such that they can overheat and self-destruct, even if scrammed, because cooling is an absolute requirement at all times. - A lack of redundant, auxiliary, passive cooling ability, such as a gravity-fed reservoir that can be operated manually. - Regulators did insufficient due-diligence to prevent these risks. - "Made in Japan" failure of culture (this was part of the final report). - Using radionuclides that are inherently dangerous and produce forever waste rather than cheaper alternatives like solar with PES. Japan's solar just overtook nuclear, but still relies heavily on coal and gas. BWRs are inherently nastier than PWRs. Non-problems at FD: - Scramming worked properly, but the primary loops were still hot. Disclaimer: Worked in the nuclear industry where hostnames were Simpsons' character names.

shagie 3y ago

Out There Learning - The Greatest Ever On-Land Fault Movement - https://youtu.be/LUsIIJwxPYU https://youtu.be/LUsIIJwxPYU (length: 4m 25s) > Where is the world's greatest known on-land fault movement of any individual earthquake? It's at a place called Pigeon Bush near Wellington New Zealand. It is the surface trace of the Wairarapa Fault. In 1855 a magnitude 8.2 earthquake offset a small stream bed by about 18.5 metres which is the greatest single-event fault movement of any on-land fault in the globe!

londons_explore 3y ago

Can this be measured using optical flow of satellite images? Optical flow can easily measure displacements far smaller than 1 pixel over a large area.