Content warnings when talking about disasters on social media

Posted on November 10, 2022 by Chris Rowan

Like many others as Twitter continues its apparent spiral towards death eternally gridlocked dysfunction, I have been testing the waters on the distributed social network Mastodon. So far, I’ve been quite enjoying it, but it has been a big system shock for the people already there, both in terms of the physical demands of handling so many more people, and in terms of having to deal with a large new population who are more habituated to the way things work on “the bird site” than the norms and practices that have emerged over many years on Mastodon.

One particular point of friction in this clash of cultures seems to be the use of “content warnings”. The ability to do this, which hides most of your posts under a description until the user clicks, is built right in, and there seems to be a general attitude amongst longer-term users that you should take advantage of this functionality whenever your content could potentially upset someone.

Essentially, you are giving people the choice about seeing something potentially upsetting that pops up in your feed, versus forcing them to see it. As some have pointed out, there is certainly potential for abusing content warnings, by insisting on them to stifle ideas or experiences you don’t want to engage with. But this is not the case when I am posting about the death toll and effects of deadly disasters. To be honest, I am rather disappointed in myself that it took moving a social network to have a discussion about when content warnings might be appropriate when talking about earthquakes, volcanoes and other disasters.

Proposed content warning policy for Mastodon

  1. When discussing any natural disaster, I will use a content warning when:
    • Posting a picture or video showing significant damage or destruction, particularly where significant death or injury has likely resulted.
    • Discussing death and/or widespread destruction due to a disaster.
  2. When I am discussing the causes of a geological disaster, or other scientific information about it, whilst that disaster is ongoing, and in the immediate aftermath, I will also use a content warning. Hashtags will either be generic (#earthquake) or a modified version of the public hashtag for that event (#HoodEruptionScience). This is to prevent these discussions drowning out more urgent information about the disaster – emergency response information, for example.
  3. In both cases, the content warning will be as specific as possible, for example “Discussion of deadly earthquake in Indonesia in 2004”, or “Scientific discussion of ongoing volcanic eruption in…”.

With regard to item 2., it may be that Mastodon, because of its different organization, does not become a real-time news feed in the way that Twitter has become. But it is best to err on the side of caution, at least for now.

Content warning policy for Twitter(?)

Since I am still nominally active on Twitter, I have also considered what such a policy might look like there, where you can give pictures content warnings but not entire tweets. Making the first tweet in a thread a content warning might quasi-work, because sometimes only the first tweet in a thread is made visible in someones timeline, but in my experience it doesn’t always work that way. I will see what happens if the circumstances arise.

Categories: bloggery, geohazards, public science, society

Juno reveals Europa’s evolving surface

Posted on November 8, 2022 by Chris Rowan

About a month ago, NASA’s Juno probe buzzed the Jovian moon Jupiter, and we got this cool picture, taken from a distance of about 400 km away.

The icy surface of the Jovian moon Europa, criss-crossed by often darker colored ridges that record fracturing of the surface.
The icy, fractured surface of the Jovian moon Europa as pictured by the Juno probe during its flyby on September 29 2022. Source: NASA/JPL-Caltech/SwRI.

The grooves and ridges criss-crossing Europa’s icy shell are thought to record water from Europa’s subsurface ocean reaching the surface through fractures in the crust. Even cooler, one of the oldest rules in the geological book – the principle of cross-cutting relationships – can be applied to this image to demonstrate exactly why Europa is such an exciting world.

The principle of cross-cutting relationships basically states that if one geological feature cuts through another, then the feature doing the cutting is younger than the feature being cut (which has to exist first, in order to be cut through). It’s commonly applied to igneous intrusions:

A vertical sheet of dark igneous rock cutting through horizontal layers in the cliff of pale sandstone
Dike intruding the Late Cretaceous Eagle Sandstone in Montana. Source: Montana Earth Science Picture of the Week

But you can also apply it to features like faults:

Wall of a quarry with three rock units - white at the base, black in the middle, yellow at the top - that tilt to the right. These formations have all been displaced downwards across two faults in the centre of the picture.
A sandstone and shale sequence disrupted by 2 normals faults in the wall of a quarry in Lancashire, UK. Source: Fault Analysis Group, University College Dublin.

And erosion surfaces:

A mountainside with horizontal red rock layers on the peak, with steeply tilted grey rocks making up the lower slopes.
A spectacular angular unconformity in Peru. Source: unknown, let me know if you know!

and, importantly, mysterious grooves on other planets. Starting with the wider purple grooved terrain (purple), we can build up a sequence of shell-cracking events by tracing the network and observing which ridges cut through which others. Green cuts purple. Blue cuts green. Red cuts blue. Orange then cuts red – and so does that weird region that looks like some sort of landslide (shaded yellow). Because blue and yellow do not cross each other, it’s not possible to get their relative timings.

Surface of Europa progressively filled in with colored lines to illustrate how earlier forming ridges are disrupted by the formation of later ones.

These observations of feature being overprinted by feature, which is then overprinted by yet another feature, is some of the key evidence of Europa being an active world, with a surface that is being reshaped over and extended period of time. I’ve quickly sketched out a sequence of six distinct events where Europa’s shell has fractured, but there are more: for instance, the wide grooved terrain I shaded purple actually cuts across several generations of older ridges.

As on Earth, the power of relative dating is that you can use simple observations to show which events happened in what order. The weakness is that it doesn’t giving you absolute ages or durations. But knowing how the story goes is pretty important, even if you don’t know the tempo – and it is how geologists in the 19th and early 20th centuries unravelled the fundamentals of the history of our planet, way before radiometric dating could put absolute ages on things.

Categories: geology, planets, structures, tectonics

The beautiful geological info-art of John Emslie

Posted on November 2, 2022 by Chris Rowan

Look at this beautiful 19th century infographic, courtesy of the History of Geology on Twitter:

Here it is in all it’s glory:

Old fashioned plate of land around an ocean, with various geological processes depicted

Except for the somewhat interesting landscape associated with label 12 – “Earthquakes and elevations of the land by subterranean forces”, there’s much in this picture of the forces shaping the Earth’s surface that would still fit into a modern physical geology class.

As you can see, this gem was presented in response to another of Emslie’s engravings, a graphical depiction of the history of life on Earth which would not fit very well into a modern paleontology class (in some versions, it is titled the ‘Antediluvian World’).

But the reference to “12 geological cards” sent me down the internet rabbit hole, since I couldn’t help but wonder – what are the other 10?

It was hard to get to a definitive list, but here are some of the cooler ones I found, mostly through the Internet Archive, which also introduced me to the dangerous potential time sink of the David Rumsey Map Collection.

Popular Geology (1849)

A stratigraphic column depicting rock units found in the UK in order of formation, surrounded by sketches of fossils and geological exposures and phenomena.
Published by James Reynolds, 174, Strand. Oct, 1st. 1849. Drawn & Engraved by John Emslie. From the David Rumsey Map Collection at the Internet Archive.

A stratigraphic column for the the rocks exposed in the UK, with other geological tidbits around it. Shedding some light on the controversies of the time, the ‘Fossils’ section on the right succinctly outlines the uniformitarian/Deep Time view of Earth history, then ends with

The results of geological investigations are in perfect harmony with the statements of Revelation, and tend to exalt our ideas of that Almighty Being who formed the earth, and all things therein.

Geological Map of England (1849)

Old geological Map of England, with different rock units marked with different colors.
Drawn & Engraved by John Emslie. London, Published by James Reynolds, 174, Strand. Decr. 13th. 1849. From the David Rumsey Map Collection at the Internet Archive.

Not quite up the standards of William Smith’s 1815 map, but I was rather tickled by the curvy cross-section line across Southern England. There are also maps of Scotland and Ireland.

Phenomena of Volcanoes and Earthquakes, showing the influence exerted by the heated interior of the Earth upon its external surface (1852).

19th Century map showing known events of earthquake and volcanic activity
Drawn and engraved by John Emslie. London, Published by James Reynolds 174 Strand. June 3, 1852. From the David Rumsey Map Collection at the Internet Archive.

I love this one, especially how it shows how the association of volcanoes and earthquake regions around the Pacific was already known. The 1755 Lisbon earthquake is given huge prominence, even a century later – the New Madrid earthquakes in the US are also marked. No sign of the East African Rift Valley, though!

Geological Map of the World

A map of the world subdivided according to the types of rocks exposed on the surface (at least as understood in the mid-19th century)
Published by James Reynolds, 174, Strand. London.

This is certainly ambitious for its time! It also uses the Primary-Secondary-Tertiary division of geological time, which has long been superseded.

Mountains (1851)

The highest mountains from every continent drawn on the same plate so their heights can be compared.
Drawn and engraved by John Emslie. London. Published by James Reynolds 174 Strand. Published by James Reynolds, 174, Strand. From the David Rumsey Map Collection.

Enslie draws his mountains with an extremely high degree of vertical exaggeration – I’m not sure if it’s a stylistic choice because they look cooler that way, a pragmatic choice to squeeze more into a confined space, or a combination of the two. Also – smoking volcanoes!

Another thing of note is that the highest mountains in Asia excluded Everest (only confirmed as higher than Kangchenjunga in 1852) and K2.

Waterfalls (1846)

A print of many different waterfalls around the world.
The highest waterfall shown is “Cataract of Gavarny (Pyrenees)”, and the lowest is the “Last cataract of the Nile”. Drawn and engraved by John Emslie. London. Published by James Reynolds 174 Strand. Published by James Reynolds, 174, Strand. Oct, 1st. 1849. From the David Rumsey Map Collection.

Had to include this one for Anne, but I give it high marks for artistry. There is also “A panoramic plan of principal rivers and lakes” where she can mutter about the inclusion of the Black and Caspian Seas.

I don’t know if all of these count as part of the 10 “geological cards”, but they are all very interesting examples of what we would now call “infographics” from the mid-19th century.

Categories: geology

The moment for nuclear power to save us was twenty years ago – and it didn’t happen

Posted on September 17, 2022 by Chris Rowan

Via Dr. Jonathan Foley on Twitter, a recent opinion piece in the NYT argues that despite it remaining popular amongst some advocates, “Nuclear power still doesn’t make much sense”.

The problem with nuclear is that we’ve been having the same conversation for 20 years or more. In the absence of heavy government subsidy, no one has built much. And we seem no closer to working out how to build nuclear plants more quickly and cheaply.

Is an alternative reality where massive oil & gas subsidies were shifted to nuclear in the 1990s and 2000s one where we’d be in a better climate & emissions situation? Maybe. However, the need in that parallel universe to overcome strong environmental & petrobusiness headwinds seem to make it a rather unlikely counterfactual.

In our actual reality, as the NYT piece argues, other solutions have now emerged with compelling speed and cost advantages, and less environmental baggage – however unfair you think the latter is. And because we’ve left our response so late, speed matters most of all.

[collated from this Twitter thread]

Categories: environment, society

A deep origin for the Tohoku earthquake?

Posted on September 14, 2022 by Chris Rowan

So if I’m reading this summary in Eos right, there is a new study suggesting that there was significant deformation of the subducted plate in the lead up to the M9 2011 Tohoku earthquake occurred – enough mass was redistributed to measurably change the local gravity field.

There is a mechanical connection between the sinking/subducting plate and the surface – that’s what generates the ‘slab pull’ force that is one of the main drivers of plate tectonics. So a connection – whereby deformation deeper beneath Japan influenced the behavior of the the megathrust near the trench – is not implausible.

Cross-section through subduction zone at Japan Trench, illustrating the proposed sequence of events suggested by gravity data ahead of the 2010 Tohoku earthquake, where deformation in the deep slab preceded the shallow rupture at the trench.

However, the normal caveats about stuff like this apply:

  • finding a signal after the fact for one earthquake does not mean that we can reliably detect such signals before other earthquakes.
  • finding a potential signal does not mean we can predictably understand what it means.

In other words, we still can’t predict earthquakes.

[post collated from this Twitter thread]

Categories: earthquakes, geohazards, geophysics, tectonics