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>"The study found approximately 793 gigagrams, or more than 15 million gallons, of mercury is frozen in northern permafrost soil. That is roughly 10 times the a

>"The study found approximately 793 gigagrams, or more than 15 million gallons, of mercury is frozen in northern permafrost soil. That is roughly 10 times the amount of all human-caused mercury emissions over the last 30 years, based on emissions estimates from 2016. >The study also found all frozen and unfrozen soil in northern permafrost regions contains a combined 1,656 gigagrams of mercury, making it the largest known reservoir of mercury on the planet. This pool houses nearly twice as much mercury as soils outside of the northern permafrost region, the ocean and the atmosphere combined. Gigagram? Never heard that one before.. uh a billion (US) grams? So.. a million kilos..a thousand tonnes..a kilotonne. or 1,656 gigagrams = 1.656 million tonnes, I think. (Weird that the imperial unit is gallons, a measure of volume I thought) This doesn't sound good. Also I'm surprised that human mercury emissions in the last 30 years were so high. Since the late 80s..sheesh.

userbinator 9y ago
(Weird that the imperial unit is gallons, a measure of volume I thought) It is volume. The density of mercury is 13.69 g/cm3 and thus 793E9 grams is 5.8E7 litres, or 1.5E7 gallons. "more than 15 million gallons" is correct.
infogulch 9y ago
You're recalling correctly, gallon is a measure of volume. I would assume they used density conversions just to make it into a "relatable" measure for US readers. But there is no US-gram. The SI unit for mass is the kilogram, (for which "kilo" is shorthand), where kilo- and giga- are standard SI prefixes. Units and prefixes are designed to be mixed and matched, so gigagram is just as valid as kilogram, even if it's more rare. Edit: thank you userbinator for the base unit correction. I've edited above to not be blatantly wrong.
- userbinator 9y ago
  The SI unit for mass is the gram, (not "kilo" which is just shorthand for kilogram, which is just commonly used because it's relatable) The SI base unit for mass is actually the kilogram. It is memorable and notable for being the only base unit that already has a prefix.
  - infogulch 9y ago
    Oh, thank you for the correction, not sure why I forgot that. > the only base unit that already has a prefix. That is interesting. So is kg actually not designed to work with other prefixes? Is it supposed to be megakilogram vs gigagram? Or are you just supposed to convert to something else or always use scientific notation? Or am I right about gigagram being valid, but for the wrong reasons?
    - freeone3000 9y ago
      The kilogram the SI standard. It's used in kilogram-meter-second reasoning systems as the base of derivative units, such as Newtons (1kg * G) or torque (N*m). (Basing these off of the gram would be... weird. You might protest the gram's the wrong size, but it's too late to change it.) Prefixes are applied as normal to 'gram' despite this (so milligram, microgram, and exotically gigagram) are correct. Gigagram just seems exotic in the same way that megameter does - it's perfectly correct and understandable, it's just rarely necessary.
      - ahoka 9y ago
        Some sciences used to prefer (or still prefer?) doing it the other way and use the CGS system, where you prefix meter instead of gram. https://en.m.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_units https://en.m.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%8...
    - NamTaf 9y ago
      No, it's supposed to be used just like others, it just has a prefix at its 'base' unit. Milligram and Megagram would indeed be technically right, but no one uses it (edit: in the case of megagram, thanks daveguy). I suspect this is because, sort of like length, there's many different names for essentailly different orders of magnitude and you'd first go to the largest (a tonne, 1000 kg) before adding on prefixes. I suspect this many-names factor is in turn because they're such historical things that humans have measured and quantified since prehistory, because distance and mass are the first 'quantities' we begin to encounter. So instead of 793 gigagrams, I'd say 793 thousand tonnes, or 793 kilotonnes.
- yesenadam 9y ago
  Hehe thanks, yeah. I meant US billion (10^9 not 10^12). I'm not saying 'gigagram' isn't valid, just I'd never heard it used before so had no sense how big it is. Amounts that big are usually talked about in millions or billions of tonnes or something like that. (1 tonne = 1000kg) Hmm this is harder than I thought, USA doesn't have the "o" sound in "tonne" either, hehe—it rhymes with "pot" for non-US speakers of English, 'on' with a 't' in front.
  - virusduck 9y ago
    The differing meanings of billion, trillion, etc. drive me crazy. WHY DOES IT HAVE TO BE THIS WAY???
  - infogulch 9y ago
    Ah you're talking about short scale and long scale. Actually most English speaking countries use short scale, even in the UK for official sources. It's unfortunate that there are so many hiccups in communicating numbers and units even with the SI system.
- jboles 9y ago
  US seems to use the kilogram for one and only one thing: reporting the size of drug hauls.
- Turbots 9y ago
  1 kg is the weight of 1 liter of water and has the volume of 1 dm³ (1 cubic decimeter or 1000 cubic centimeters)
- lyk 9y ago
  There is US-gram. See slug, pound-mass.
red75prime 9y ago
1,656 gigagrams = 1,656 10^9 grams = 1,656 10^3 tonnes = 1,656 thousand tonnes
mikejb 9y ago
The "Gigagram" makes me smile. The one thing where the metric system annoys is the "ton" and "kilo-ton" labeling. A ton is 1000 kilograms, hence a megagram, and a gigagram is 1000 megagrams.
- marcosdumay 9y ago
  The "ton" is not strictly an SI unity. It's widely accepted, but it's not an insider :)
- beojan 9y ago
  It's all a bit of a mess because the SI base unit is the kilogram, not the gram.
  - mikejb 9y ago
    Yes, that is a bit annoying as well, but I made my peace with that (Probably also because I'm not affected by it directly). But the "ton" is a constant companion, and when it then gets to "kilo-tons" it just breaks the entire SI-prefix system to bits.
    - beojan 9y ago
      In practice, I just think of it as two base units: grams for small masses (i.e. prefixes smaller than 1 aren't used with tonnes), and tonnes for large ones. (Though terms like kiloton and megaton may well be referring to the US ton (2000 lb) or the Imperial ton (2240 lb) rather than the Metric (1000 kg) one). Hey, it's still simpler than the American system.
- yesenadam 9y ago
  Far as I know (not far), 'tonne' (1000kg) /ton/ is metric and 'ton' (not 1000kg) /tun/ is imperial.
  - mikejb 9y ago
    Yep, you're right, I messed that up.
chrisweekly 9y ago
"tonnes" as a metric unit is new to me. (vs imperial "tons", ie 2,000 lbs)

userbinator 9y ago

(Weird that the imperial unit is gallons, a measure of volume I thought) It is volume. The density of mercury is 13.69 g/cm3 and thus 793E9 grams is 5.8E7 litres, or 1.5E7 gallons. "more than 15 million gallons" is correct.

infogulch 9y ago

You're recalling correctly, gallon is a measure of volume. I would assume they used density conversions just to make it into a "relatable" measure for US readers. But there is no US-gram. The SI unit for mass is the kilogram, (for which "kilo" is shorthand), where kilo- and giga- are standard SI prefixes. Units and prefixes are designed to be mixed and matched, so gigagram is just as valid as kilogram, even if it's more rare. Edit: thank you userbinator for the base unit correction. I've edited above to not be blatantly wrong.

userbinator 9y ago
The SI unit for mass is the gram, (not "kilo" which is just shorthand for kilogram, which is just commonly used because it's relatable) The SI base unit for mass is actually the kilogram. It is memorable and notable for being the only base unit that already has a prefix.
- infogulch 9y ago
  Oh, thank you for the correction, not sure why I forgot that. > the only base unit that already has a prefix. That is interesting. So is kg actually not designed to work with other prefixes? Is it supposed to be megakilogram vs gigagram? Or are you just supposed to convert to something else or always use scientific notation? Or am I right about gigagram being valid, but for the wrong reasons?
  - freeone3000 9y ago
    The kilogram the SI standard. It's used in kilogram-meter-second reasoning systems as the base of derivative units, such as Newtons (1kg * G) or torque (N*m). (Basing these off of the gram would be... weird. You might protest the gram's the wrong size, but it's too late to change it.) Prefixes are applied as normal to 'gram' despite this (so milligram, microgram, and exotically gigagram) are correct. Gigagram just seems exotic in the same way that megameter does - it's perfectly correct and understandable, it's just rarely necessary.
    - ahoka 9y ago
      Some sciences used to prefer (or still prefer?) doing it the other way and use the CGS system, where you prefix meter instead of gram. https://en.m.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%80%93second_system_of_units https://en.m.wikipedia.org/wiki/Centimetre%E2%80%93gram%E2%8...
  - NamTaf 9y ago
    No, it's supposed to be used just like others, it just has a prefix at its 'base' unit. Milligram and Megagram would indeed be technically right, but no one uses it (edit: in the case of megagram, thanks daveguy). I suspect this is because, sort of like length, there's many different names for essentailly different orders of magnitude and you'd first go to the largest (a tonne, 1000 kg) before adding on prefixes. I suspect this many-names factor is in turn because they're such historical things that humans have measured and quantified since prehistory, because distance and mass are the first 'quantities' we begin to encounter. So instead of 793 gigagrams, I'd say 793 thousand tonnes, or 793 kilotonnes.
yesenadam 9y ago
Hehe thanks, yeah. I meant US billion (10^9 not 10^12). I'm not saying 'gigagram' isn't valid, just I'd never heard it used before so had no sense how big it is. Amounts that big are usually talked about in millions or billions of tonnes or something like that. (1 tonne = 1000kg) Hmm this is harder than I thought, USA doesn't have the "o" sound in "tonne" either, hehe—it rhymes with "pot" for non-US speakers of English, 'on' with a 't' in front.
- virusduck 9y ago
  The differing meanings of billion, trillion, etc. drive me crazy. WHY DOES IT HAVE TO BE THIS WAY???
- infogulch 9y ago
  Ah you're talking about short scale and long scale. Actually most English speaking countries use short scale, even in the UK for official sources. It's unfortunate that there are so many hiccups in communicating numbers and units even with the SI system.
jboles 9y ago
US seems to use the kilogram for one and only one thing: reporting the size of drug hauls.
Turbots 9y ago
1 kg is the weight of 1 liter of water and has the volume of 1 dm³ (1 cubic decimeter or 1000 cubic centimeters)
lyk 9y ago
There is US-gram. See slug, pound-mass.

red75prime 9y ago

1,656 gigagrams = 1,656 10^9 grams = 1,656 10^3 tonnes = 1,656 thousand tonnes

mikejb 9y ago

The "Gigagram" makes me smile. The one thing where the metric system annoys is the "ton" and "kilo-ton" labeling. A ton is 1000 kilograms, hence a megagram, and a gigagram is 1000 megagrams.

marcosdumay 9y ago
The "ton" is not strictly an SI unity. It's widely accepted, but it's not an insider :)
beojan 9y ago
It's all a bit of a mess because the SI base unit is the kilogram, not the gram.
- mikejb 9y ago
  Yes, that is a bit annoying as well, but I made my peace with that (Probably also because I'm not affected by it directly). But the "ton" is a constant companion, and when it then gets to "kilo-tons" it just breaks the entire SI-prefix system to bits.
  - beojan 9y ago
    In practice, I just think of it as two base units: grams for small masses (i.e. prefixes smaller than 1 aren't used with tonnes), and tonnes for large ones. (Though terms like kiloton and megaton may well be referring to the US ton (2000 lb) or the Imperial ton (2240 lb) rather than the Metric (1000 kg) one). Hey, it's still simpler than the American system.
yesenadam 9y ago
Far as I know (not far), 'tonne' (1000kg) /ton/ is metric and 'ton' (not 1000kg) /tun/ is imperial.
- mikejb 9y ago
  Yep, you're right, I messed that up.

chrisweekly 9y ago

"tonnes" as a metric unit is new to me. (vs imperial "tons", ie 2,000 lbs)