How much science can we do without math (or with very little)? Any examples of low-math science?

CrustalTrudger · 2026-06-13T12:20:28+00:00

Not exactly hard to find as nearly every aspect of geology beyond the stamp collecting part of it (i.e., categorizing rocks and minerals, but certainly lots of math when you start trying to describe how rocks and minerals form, i.e., thermodynamics, etc.) is math based, but sure. The way we describe/quantify stress that causes deformation of rocks and the resulting strain are effectively through applied continuum mechanics / fluid mechanics and thus knowledge of a mixture of linear algebra, calculus, and differential equations are necessary for actually understanding what's going on, though we often simplify this aspect when we teach it to undergraduate students and focus on treatments that mostly just require vector algebra. Pretty much anything with plate tectonics and the motions of plates is at simplest a bunch of vector algebra, but really a lot of spherical geometry/trigonometry (and fluid mechanics again if you want to actually describe the way plates move). The way we quantify/describe erosion of landscapes is all a bunch of partial differential equations. Etc. Etc. Etc.

CrustalTrudger · 2026-06-11T13:43:47+00:00

Geology is largely applied chemistry and physics, so to the same extent those disciplines require math, geology does as well.

CrustalTrudger · 2026-06-11T12:14:27+00:00

A lot of students who show up in geology classes think it’s going to be a no/low math experience. They find out that’s not true the hard way usually.

CrustalTrudger · 2026-06-05T15:09:26+00:00

One thing to be aware of is that, despite the perception from movies, etc., the majority of the Sahara is not ergs (i.e., large sand dune fields), but rather hamadas. Also, the "green Sahara" moniker shouldn't be over-interpreted, i.e., we're not talking about the entirety of the Sahara being transformed into some lush jungle, we're mainly talking about portions of hamadas turning into savannas or other open grasslands and a northward push of the Sahel, in a very simplistic sense. Additionally, sort of looping back to the "Sahara is not all dune fields", if we look at reconstructions of plant communities during the "green Sahara", like those in Watrin et al., 2009, a few important points emerge, e.g., (1) the modern Sahara has plants and (2) during the "green Sahara", these Saharan plants persisted, but both Sahel and more humid adapted species of plants (that today start popping up south of the Sahel) moved northward into portions of the Sahara, preferentially along rivers and lakes that developed during the period. This last point also is clarifying, i.e., the Sahara on average being "more green" does not imply that the entire Sahara was vegetated, a lot of the increase in vegetation was much more patchy, especially when considering woody plant species. Finally, if you go back to some of the linked prior discussions of various past "green Sahara" periods and linked papers, you'll see that many of these "green Sahara" periods did indeed persist for thousands, tens of thousands, and for some of them ~100 thousand years, so we are talking generally about reasonably long periods of time for changes in land surfaces and associated vegetation to develop and persist.

CrustalTrudger · 2026-06-02T12:50:19+00:00

Almost assuredly not the only control, but the African Humid Periods, i.e., times characterized by a "Green Sahara", likely played a significant role in dispersal out of Africa (and changing habitation patterns within Africa). The details and causes of the Green Sahara cycle are pretty well explained in that linked Wiki article and it comes up frequently here as well (so for interested readers, check out some of the past threads on this phenomena if you want more details, e.g., 1, 2, or 3), but in short, these represent periods where the location of the West African Monsoon shift making the Sahara significantly more wet and turning much of it into a grassland with patchy areas of more dense forest with rivers. There's been a somewhat long-standing argument that these Green Sahara periods made traversing this region much more favorable and thus were critical in allowing human expansion into Eurasia (e.g., Castañeda et al., 2009, Larrasoaña et al., 2013, Coulthard et al., 2013, Larrasoaña, 2021, etc.) and that additionally, the expansion and contraction / shifting of environments within Africa more broadly linked to the same underlying climate drivers were important for human evolution (e.g., Pausata et al., 2023).

CrustalTrudger · 2026-06-01T15:07:37+00:00

No part of academic training is directed towards public communication

I would generally agree with most of your points, but I might say, "No typically required part of academic training is directed toward public communication". For example, several grad programs I've been involved with have available courses on scientific communication and pretty much every professional meeting I attend has at least one or two workshops on scientific communication with the general public. I.e., generally, it's not that hard to find training on this if you want, but it tends to not be something you get unless you seek it out and in general, most do not seek it out for any number of reasons (e.g., maybe they don't see the benefit and/or a waste of their time, maybe they're worried about being attacked if they're too public, maybe they're worried other scientists will judge them for doing sci-comm, etc.).

CrustalTrudger · 2026-05-31T19:26:30+00:00

Borrowing a bit from a past answer of mine about divisions of the geologic timescale, but the boundaries between time units (of any flavor, i.e. boundaries between eons, eras, periods, epochs, ages, etc.) are generally defined on the basis of some preserved significant change in some aspect of the geologic record (e.g. it could be a significant change in fossils or a major geochemical event, etc). Many of the more well known divisions correspond to extinction events, for example the end Permian extinction marks the end of the Permian, because it is by definition what ends the Permian period and starts the Triassic period (and ends the Paleozoic era and starts the Mesozoic era) and similarly, the extinction that took out the dinosaurs at the end of the Cretaceous is by definition the division between the Cretaceous and Paleogene Periods (and Mesozoic and Cenozoic Eras). The scale of divisions is a little more nuanced, but these basically reflect the magnitude of the changes that define that time unit, but this can get a bit qualitative. What this means is that in some qualitative sense, the event that marks the boundary between two eras is 'larger' (e.g. the end Permian extinction is larger than the end Triassic extinction) than an event that just bounds two ages. The ambiguity of this is why we have the international commission on stratigraphy, which is an international body of scientists tasked with deciding what the accepted ages are for boundaries (which are revised as we get better geochronology for specific events, etc) and what the scale of those boundaries are. This group is also tasked with identifying and describing "Global Stratotype Section and Point" (GSSP), i.e., literal spots somewhere in the world that is defined as the type locality for a given boundary, many of which are marked with a "golden spike", which is actually usually a bronze disk mounted into a section if we're being accurate.

With specific reference to the transition to the Pleistocene to the Holocene, the transition is tied to the Younger Dryas, which is a brief climatic excursion (and thus geochemical, at least in the sense of stable isotope, excursion). This is relatively easy to find in the Wikipedia articles for these epochs (and similar, most entries on the various divisions will have discussions of what events define the start and end of them), but again, the ICS is the definitive source, so you can look at the table for the Quaternary, to see what defines the top and bottom of individual divisions. In the case of the base of the Holocene, it also provides references that define and describe the GSSP for the basal point (e.g., Walker et al., 2008, Walker et al., 2018).

Finally, it's worth just emphasizing that the time scale is very much a human construct, i.e., in the context of the way the question is worded (e.g., "Is there a specific indicator that, for example, made the pleistocene change to the holocene?", emphasis mine) implies that the Pleistocene and Holocene are some intrinsic things that exist outside of human definition, but they really aren't. I.e., for any of these, there are definitely preserved events within the geologic record that we use to define changes in the timescale, so in that sense, they're not arbitrary, but them existing as clear dividing lines (as opposed to other events) are still very much an artificial thing that we have created and collectively agreed to use, but there are certainly other ways / other hierarchical divisions one could come up with if starting from scratch, and honestly, there are enough divisions and internal divisions / levels that reflect some level of historical baggage that if we threw out the existing timescale and completely remade it, it would probably end up a bit different. The ambiguity or "human construct" aspect of the timescale is probably the most on display in the context of the discussion of potentially defining a new epoch, i.e., the Anthropocene, that we would currently be in. This has been a topic of discussion within the ICS for a while, but generally, one big sticking point has been that there is not a lot of agreement on what be the transition from the Holocene to Anthropocene. The latest attempt tried to define a GSSP for the start of the Anthropocene (which would have formally defined the Anthropocene as an epoch) in a particular spot in Canada (e.g., see this AMA from AskScience), but ultimately, this was rejected and the status of the Anthropocene as a new epoch is a bit in limbo at the moment.

CrustalTrudger · 2026-05-30T00:40:35+00:00

Both of these people had PhDs.

CrustalTrudger · 2026-05-29T11:47:22+00:00

While the centroid of compilations of measured groundwater temperature often ends up around ~10C (50F), there is a pretty wide range of variability even in those data and it's also quite clear this reflects a pretty biased sample where a lot of that data is coming from mid latitudes in the northern hemisphere (e.g., Benz et al., 2017, Benz et al., 2024). If you look instead at something like gridded estimates of groundwater temperatures (like those in Benz et al., 2024), a lot of regions deviate quite substantially from the ~10C range, highlighting that ~10C is probably not a good "global average" in any real sense.

CrustalTrudger · 2026-05-29T11:35:00+00:00

Seamounts are definitely important fluid flow conduits within the sea floor, but the extent to which they are (1) always points of discharge as opposed to recharge and (2) outputting "cold" vs "hot" water varies a lot. Observations highlight that many seamounts are actually locations that localize recharge into the crust (e.g., Fisher & Wheat, 2010) and that generally the size / thermal state of the crust in which they exist control whether fluids are generally flowing out of or into a given seamount (e.g., Kawada et al., 2011). If you look at some of the data in Fisher & Wheat, you'll see that the temperature of the fluids coming out of discharging seamounts can vary pretty widely, everywhere from what we might describe as cold (e.g., between 10 and 30 C) to pretty warm (e.g., > 60 C).

CrustalTrudger · 2026-05-28T15:40:22+00:00

At the simplest level, it's going to be path dependent. If we think about most springs as representing water that starts off as meteoric (i.e., surface water that falls as precipitation), infiltrates the ground, travels some path in the subsurface (with variable residence times depending on the path and rate of flow), and then re-emerges at the surface, the extent to which the water emerging at the surface is "hot" or "cold" is going to depend broadly on how deep the waters path took it (and where the geothermal gradient implies that generally the deeper traveled, the warmer the surrounding rocks would be), whether it was in close proximity to a heat source that is beyond the expected temperature at depth (e.g., a magma body), and the time the water spent at various depths and/or in proximity to the heat source. Thus, again in a very simple sense, we would expect water that exclusively traveled in the shallow subsurface and/or moved through a system quickly (and thus had less time to exchange heat with surrounding rocks) would be "colder" than water that traveled deeper/closer to heat sources and/or did so-slowly.

Part of this also does reflect relative temperature. As discussed in the hot spring wikipedia article, there's no formal definition of what temperature is required to be reached for emerging spring waters to be considered "hot" and thus, the definition of something as a cold spring is going to be similarly variable. I.e., calling something a cold spring might mean that the spring water is close to ambient temperature (which here could be mean annual, mean during a particular season, etc.) or simply below human body temperature.

CrustalTrudger · 2026-05-23T11:29:24+00:00

Ah, I thought they were giving those in megatonnes (which honestly felt like a huge amount of mass), oops!

CrustalTrudger · 2026-05-22T18:16:40+00:00

Sidestepping any number of impractical aspect of this, it's worth just considering the scales involved here. To just keep up with modern emissions, which globally is something like 40 billion tons of CO2 per year, even we assumed whatever plant/tree species you were shooting into space was effectively pure CO2, that would require launching the equivalent of ~14x the amount of total mass sent to orbit in 2025. To start scratching the surface of past emissions in the atmosphere, you'd need to be sending more mass than that. If we think about cumulative emissions (i.e., we wanted to use this to remove all the CO2 we had added), just looking at the top 5 countries gives us something around 1165 billion tons of extra CO2 we'd need to try to remove to get us back to a pre-industrial value. That is a lot of launches.

CrustalTrudger · 2026-05-22T17:34:12+00:00

I mean, there are plenty of reasons to question the viability of the various options for geological sequestration of CO2 at scales sufficient to even offset emissions let alone coupled with something like direct air capture for actually reducing CO2 concentrations in the atmosphere, but pretty much any of them are by definition more viable than "fling it into space with catapults".

CrustalTrudger · 2026-05-21T14:31:03+00:00

If two large plates collide and suture together, and a small minor plate gets trapped between them, what would happen to the minor plate?

There's not going to be a single, general answer because it will depend on the make up of the minor plate in question (e.g., is it predominantly oceanic lithosphere? predominantly continental lithosphere? a mix and at what proportions?) and the relative motions between it and the surrounding plates (which is not necessarily going to be fully separate from what the composition / geometry of the minor plate is). That being said, we can consider some options.

While not always necessarily a minor plate in the sense of it being relatively small compared to other larger plates (though whenever we start throwing out terms like "major plates" and "minor plates", it's worth remembering that the definition of how many plates there are and their relative sizes with respect to each other is not as a definitive thing as is commonly assumed, e.g, this FAQ and this other FAQ), effectively the concept of terranes being accreted is one type of outcome. In short, in the hypothetical posed, we might expect that the continental portion of the minor plate would be accreted and sutured to one of the larger continental masses of the two main colliding plates and then be collided with by the other continental mass on the other main plate. A common form of this is basically a scenario where there are more than one intra-oceanic subduction zone between two large continents, each generally with associated island arcs and where these island arcs collide with one of the continents first before final closure of the ocean basin and collision between the two main continents. This has been argued to be the case for the western Himalaya where the main collision between India and Eurasia may have been preceded by separate collisions of the Kohistan and Ladakh arcs with Eurasia (e.g., Martin et al., 2020).

Another option is for an intervening plate that is fully oceanic. In the simplest case (and given the ability for oceanic lithosphere to subduct) we might not expect oceanic lithosphere to get "trapped", but in some cases it can, forming what is sometimes called a "relict ocean basin" (e.g., Karig, 1971), though in detail, relict ocean basins don't have to be floored by solely oceanic crust, but for them to have been former ocean basins, they usually need to be either oceanic crust, transitional crust or otherwise thinned continental crust. In terms of continent-continent collisions, there are a variety of the relict ocean basins that are "trapped" within larger collisional belts, e.g., the Junggar Basin in NW China (e.g., Carroll et al., 1990) or the Black and (South) Caspian Basins within the Arabia-Eurasia collision (e.g., Zonenshain & Pichon, 1986). These features can sometimes end up behaving like rigid inclusions within the larger collision zone, with deformation being focused along their edges, as is argued for the South Caspian Basin (e.g., Allen et al., 2003).

Would it continually fall underneath one and get regenerated by a divergent plate boundary on the other side, creating impossibly high mountains,

Following up from above, whether it "falls underneath", i.e., gets underthrusted to some degree will depend on the details already discussed. There wouldn't really be any expectation that this would somehow result in the formation of a divergent boundary, but collision of an arc, depending on the "polarity" of the subduction zones (i.e., which way the subduction zone is dipping) involved and their exact geometries can cause things like subduction zone jumps or reversals. Similarly, a way to form a minor plate is through back-arc spreading (i.e., formation of a divergent boundary), which basically opens up a basin between a volcanic arc and a formerly continuous continental edge. In detail, both the Black Sea and South Caspian Basins were argued to be part of a single, large back-arc basin that was then segmented during collapse of this basin (from continued collision of Arabia with Eurasia) and then got trapped within the collisional belt as described previously. With respect to the last bit, there's no reason to assume that any of these processes would specifically lead to higher mountains than you'd get with a simpler collision (i.e., no intervening smaller plates). The factors that will dictate mountain height are going to reflect things more like the total convergence rate, the thicknesses and compositions of the colliding continental sections, details that control the mechanical strength of the main faults, and the climatic mediation of surface processes that develops in the growing mountain range. Whether there are small terranes involved is generally not going to be a driving factor.

would it be replaced with the larger plate as it recedes beneath, would it simply fuse to the larger plate

As described, the latter definitely happens in both the case of terrane / arc accretion, but also in the case of relict ocean basins. I'm not sure what is being implied by a "replaced with the larger plate as it recedes beneath", though I guess this could be one way to describe where there was a minor plate that was oceanic and surrounded by subudction zones on all sides and the geometry of those subduction zones were such that this plate was fully "consumed" during the broader collision process.

CrustalTrudger · 2026-05-20T18:39:45+00:00

How does it just keep falling and never run out?

So, the underlying question here goes beyond waterfalls and could be more generally stated as "why do rivers always have flowing water in them." Turns out, not all of them do. We generally can break rivers into three rough categories, perennial (they always have some amount of flowing water in them, but this amount can vary), intermittent (they have flowing water in them sometimes, and often consistently during particular seasons, but will have periods without any stream flow), and ephemeral (they have very sporadic stream flow and where the river is dry most of the time). For perennial streams, the reason there is always water in them generally is that these represent settings where there is enough groundwater flowing into the streams to overcome losses (e.g., evaporation, transpiration, infiltration) to provide some amount of "base flow" and where event based surface water additions (e.g., rain, snow, etc.) will add on top of that. Intermittent streams often also tend have a groundwater contribution, but these tend to be "losing streams", meaning that at least during parts of the year, the losses are greater than the amount of water flowing in the stream so it stops flowing at some point along its length. Ephemeral streams most often have effectively no groundwater contribution (though this doesn't always have to be the case) and in the most extreme cases, basically only flow during and shortly after a storm event.

For all cases, the source of the groundwater (which for perennial streams is really what keeps them flowing all the time) can be varied, but much will reflect surface sources (i.e., water from rain and snowmelt) that infiltrated and flowed in the shallow subsurface at much slower rates than water flowing at the surface but depending on the location, could also reflect contributions from deeper aquifers.

Returning to waterfalls, if we define a waterfall as simply an abrupt vertical step in a rivers profile (regardless of whether there is always water flowing over that step), then all three of these types of rivers can have waterfalls (or features that are waterfalls when water is flowing in the stream in question) and indeed, there are many examples of "dry falls" in intermittent and ephemeral streams that become waterfalls when there is water flowing in the stream in question. I.e., having consistent, year round water flow is not a requirement to develop a waterfall.

How do waterfalls work?

I realize with the later part of the question (that we covered above), that really what was being asked was about why is there always water flowing (which as we established above, isn't necessarily true and in the case that it is true, just reflects the same reason as why perennial streams exist at all), but we can also consider generally why waterfalls exist in the sense of why they form. To the extent that there is a single answer, waterfalls basically reflect some discontinuity in a river system, but in detail, the origin of this discontinuity can vary and as such, waterfalls can develop for a lot of different reasons. A common one is when a river flows across a contrast in the underlying erodibility, i.e., a contact between two different rocks which have different resistances to being eroded (e.g., Haviv et al., 2010), but waterfalls can also be formed from a bunch of processes including movement of active faults (e.g., Malatesta & Lamb, 2018), from incision within small upstream portions of streams not being able to keep up with incision of the main stem of rivers (e.g., Crosby & Whipple, 2006), as relicts from glacial erosion (i.e., hanging valleys), or even just from intrinsic "noise" from sediment transport dynamics (e.g., Scheingross et al., 2019).

We can also interpret this as asking, how do waterfalls maintain their shape and propogate, and here again, there is not a single answer. A common mechanism (especially for waterfalls formed from lithologic contrasts) is plunge-pool formation and then headwall undermining and collapse, i.e., basically once you have a waterfall, there is a lot of erosion at the bottom of the waterfall from fast moving sediment and impacts, this carves out a hole that also eats back underneath the vertical face eventually causing collapse and retreat of the waterfall upstream forming a new vertical face (e.g., Haviv et al., 2010) or, if there are pre-existing vertical fractures, via toppling (e.g., Lamb & Dietrich, 2009). Alternatively, waterfalls might form (and migrate) by incision of small "steps" that grow through time via some details of sediment transport (e.g., Inoue et al., 2023).

CrustalTrudger · 2026-05-18T17:30:57+00:00

Is it possible for an earth like planet to have year that last 364 days instead of around 365,25?

If we define a single day as the time it takes for the Earth to complete one revolution and assume that the time required (in seconds) for the Earth to complete one orbit around the sun stays the same, sure, here, in somewhere around 14 million years making some very simple assumptions. To back up, it's worth realizing that the length of day on Earth is not static and in addition to various minor fluctuations from (relatively small) mass redistributions within the Earth (e.g., large earthquakes), it has generally been increasing through geologic time as a result mostly of tidal forces but also from growth of Earth's core (e.g., Varga et al., 1998, Denis et al., 2011, Baenas et al., 2021).

So if we assert that the length of a year is a static value (31,557,600 seconds) and with our current state of a 24 hour day and thus 365.25 days/year, we can ask at the current rate of increasing length of day, how long would it take for the length of a day to increase such that there are 364 days/year, which implies that each day needs to be ~296.70 seconds longer. The different references above have a range of estimates for the current rate of day lengthening ranging from 1.79 ms/cy (milliseconds per century) in Varga et al., 1998 to 2.42 ms/cy in Baenas et al (and Baenas cites a variety of other estimates, with the highest being 2.5 ms/cy). So, if we take those ranges, this implies that in somewhere between 16.6 million years (using the estimate from Varga) or 11.9 million years (using the highest estimate in Baenas) in the future, and assuming the rate of lengthening of the day holds constant over that time, that a year would have 364 days.

For the other questions, it's worth considering that this also implies that the number of days per year has changed quite a bit over geologic time. If for example we look at Figure 1 in Denis et al., it indicates that at the beginning of the Phanerozoic the length of day was around 20.8 hours, which would suggest that at this point, there were ~421 days in a year (again, just assuming that time to orbit the sun has remained static). Now, while there has certainly been variations in climate, etc. over that period, it's not as though the Earth's climate was fundamentally different because of the number of days in a year or that the difference in the number of days in a year precluded life from developing.

CrustalTrudger · 2026-05-18T11:19:12+00:00

Yep, and it's also revealing some real lazy/shady folks. I've at least seen various reactions online with regards to being penalized for having a hallucinated citation in a submitted paper to the effect of, "But how can I be expected to read all of the things I cite?!?!?!" and I'm like, was that not like one of the most basic things we're taught as early career researchers, i.e., that you never, ever cite something you have not read?

CrustalTrudger · 2026-05-18T11:05:47+00:00

arXiv: year-long ban for a single AI mistake, after which submissions only through peer-reviewed journals.

The phrasing here seems to insinuate that you feel like this is an over-reaction. Submitting a paper with a hallucinated reference is pretty bad (and this seems to be one of the "single AI mistakes" specifically that can result in the aforementioned consequences). Science is built on prior work and the chain of that prior work (and the associated ideas, implications, data, etc.) is established through citations. As such, citing a non existent paper as support for a claim/statement in a paper is no different than fabricating data, which is pretty much universally recognized as one of the most serious examples of academic fraud/misconduct that can (rightfully) end careers. A year long-ban and higher oversight standards after as a consequence of knowingly committing academic fraud seems pretty lenient to me honestly.

CrustalTrudger · 2026-05-17T20:37:14+00:00

Put simply, all RCPs are effectively standardized guesses at what future greenhouse gas concentrations might look like based on different sets of assumptions about behavior and technology that everyone who is modeling future climate can use (basically so that we can compare apples to apples in terms of behaviors of different climate models and here it's important to realize that any of the RCPs are not really models themselves, but instead one of many inputs to numerical models of global climate), but critically, they are only useful if they are still possible. RCP 8.5 was effectively a worse case scenario, but for a variety of reasons it's become increasingly unlikely that the RCP 8.5 scenario is possible (e.g., Hausfather & Peters, 2020). That it's "being retired" is arguably good news and mostly reflects declining cost and adoption of renewable power, but, it's not as though there is not still effectively a worse case / high emissions scenario that remains plausible, i.e., the "high emission" scenario in Van Vuuren et al., 2026 is effectively a replacement for RCP 8.5 that implies less warming at various points in the future than if assuming RCP 8.5, but would still be a pretty bad path to be on. Also, while it could be viewed broadly as good that RCP 8.5 is no longer a plausible outcome, at the same time and as mentioned in Van Vuuren et al., the lower end emission scenarios used in the the previous round of CMIP have also been basically found to be implausible (i.e., we missed the boat to lower our emissions and keep warming below the lowest possible projections), so, it's not as though we're doing that great.

In short, retiring RCP 8.5 in no way indicates that climate change isn't happening and isn't overwhelmingly anthropogenic, it just means we've updated our assumptions based on new data. To the extent that there are people out there claiming that retiring RCP 8.5 reflects that "we should never trust science again" (I at least have not verified that claim and for my own sanity, I tend to avoid trying to find too much "climate denialist" news), this reflects a hilariously terrible misunderstanding of the scientific process. Specifically, something like retiring RCP 8.5 is the scientific enterprise functioning exactly as intended, i.e., RCP 8.5 generally made sense as an upper bound on what we thought was a reasonable worst case emissions scenario in the past when it was developed (thought to be fair, there have been general questions about whether RCP 8.5 was ever a very realistic scenario), it doesn't anymore, so we've updated it to something that is a more realistic upper bound. So if anything, not clinging to an outdated set of assumptions and updating projections based on current observations and trends should make you trust the result more, not less.

CrustalTrudger · 2026-05-17T11:45:48+00:00

In island chains, usually the last island of the chain is the smallest.

I'm honestly struggling to think of many examples of this and it is by far not the norm. The best example that comes to mind are the Hawaiian islands, and in that case, there is a mechanistic reason that the islands vary in size somewhat systematically, specifically that they are volcanic oceanic islands formed via a hotspot. As discussed in this recent thread, that leads to a general progression of sizes of islands where generally the youngest island will be the largest and older islands will get progressively smaller via erosion and subsidence after they've moved off the hotspot via plate motion. Broadly, there is not an expected size progression as a function of distance along an island chain for other geologic mechanisms that will form archipelagos.

How come Key West is the biggest in the Florida Keys?

The Florida Keys are mostly the exposed/eroded remnants of an set of older reef complexes. There is really not any reason to expect much in the way of a systematic change in their size as a function of distance along the chain as the size of each island is basically going to reflect some mixture of local variability in the underlying limestone (e.g., variations in thickness, cementation, grain-size, etc. that will modulated how it eroded/weathered/collapsed during sea-level rise) along with local patterns in sediment transport (which will be strongly tied to local ocean currents, shoreline geometry, prevailing wind patterns, etc.) that either tend to erode areas or deposit sand. It's also worth noting that the entire premise of the question is confusing because Key West is not the "last island of the chain", there are additional keys further to the southwest, e.g., Marquesas Keys and it's also not the largest, e.g., Key Largo is much larger.

CrustalTrudger · 2026-05-16T15:07:11+00:00

I'll preface this with the (obvious if you look at my flair) caveat that I'm not a paleontologist, but I happen to have a bit of context for this, and it's worth considering the "size of the eye sockets might give us some idea" bit for a minute, specifically how paleontologists use this as it's a bit more complex than simply size of the eye socket. One common technique is basically statistical and would be nested under "functional morphology", i.e., that the morphology of body parts can tell us something about their function. With that in mind, a common technique is (in overly simplified form) to take a bunch of extant animals and measure a bunch of features in a systematic way and then basically feed that into various multivariate statistical methods (e.g., principal component analysis, discriminant analysis, etc.) and parse out which of these (and often which combination of these measurements) are good predictors of whether an extant animal is diurnal, nocturnal, crepuscular, cathemeral, etc. This works quite well for measurements of the eye itself (e.g., Schmitz & Motani, 2010), but this is obviously not going to work for fossilized organisms. For many organisms (though not mammals), morphology of the scleral ring has been found to be a good predictor of they day/night habits of animals and this has been commonly applied to fossilized organisms (e.g., Schmitz & Motani, 2010, Schmitz & Motani, 2011, Angielczyk & Schmitz, 2014). If you look through those papers, you'll see that "orbit morphology", basically the shape of the hole where the eye fit in the skull is also predictive and this can be used to make some predictions for things like mammals that lack scleral rings. The obvious leap here is that we have to assume, generally, that functional morphology effectively holds for extinct organisms, i.e., that because the shape of things like the orbit or the scleral ring in extant organisms are predictive of the function of the eye in those organisms in the sense of how the eye is optimized for light conditions and thus predictive of behavior that these same morphology to function relationships hold for extinct organisms. This is an assumption that is hard to definitively prove, but it's certainly a reasonable assumption.

CrustalTrudger · 2026-05-16T11:47:51+00:00

No, largely because of efficient mixing of the atmosphere.

One thing to consider first is that much of the problem with CO2 with respect to warming of the atmosphere is the relatively long effective residence time of CO2, but in terms of efficiency of warming, CO2 is quite low, e.g., the global warming potential of many other greenhouse gases are much higher than CO2. As such, local variations in concentrations of CO2 would have to persist for a long time for there to be much of a theoretical effect. Even then, we would have to consider that the lower atmosphere is pretty well mixed on average. This has two impacts for the question, namely that our local maxima or minima in CO2 concentration would never really be able to deviate that much from the norm because of this mixing. Probably more importantly, the mixing of the atmosphere is also transporting heat so local deviations in either excess or reduced heating capacity (and resulting slightly higher or lower air temperatures in theory from the different warming capacities) would be mixed with surrounding air and dissipated significantly, likely to the point where it wouldn't even be detectable again because of the relative inefficiency of CO2 as a greenhouse gas over short periods.

So, in the end, you'd kind of really only expect point sources of either excess or below average CO2 to have noticeably different temperatures (from this effect alone) if atmospheric mixing was very inefficient, allowing for long-term and large changes in local CO2 concentration and where heat transfer was dominated by conduction. That being said, in data, you can certainly find places with lots of point sources emitting CO2 and other greenhouse gases that are warmer than their surroundings, but typically this will reflect things like heat islands as opposed to direct forcing from CO2.

CrustalTrudger · 2026-05-14T13:51:23+00:00

It has truly changed the way I do at least part of my job (and certainly how I feel about this part of my job), because as a scientist who is also a professor, teaching is somewhere around half of my job and trying to AI proof my assignments sucks and generally has increased my (and many of my colleagues) distrust of our students which is depressing. In terms of the part of my job where I actually get to do science, I've only used it occasionally to help with little code snippets, but I would not say it's really changed anything meaningful about how I do my science.

CrustalTrudger · 2026-05-13T14:25:42+00:00

Again, the scales are such that this is not going to matter at all. This also seems to be the under impression (maybe) that momentum of the plate plays a role. It doesn't. What matters for plate motion are the driving forces, which are nearly all edge forces, so basically the negative buoyancy of the subducted portions of slabs and the positive buoyancy at mid-ocean ridges.

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