Geo-Informative Maps: Ocean Currents

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Geo-Informative Maps: Ocean Currents

Postby BardicFire » Wed Oct 19, 2011 2:51 pm

One of the first things one needs to develop a World and determine worldly climates and life zones is Ocean Currents. Currently me and Birchbeer are working on this project, using both what little information we have canonically on this topic as well as Real World Ocean Currents. Birchbeer has offered to do a Mockup which should be coming along shortly.

Development Team:
* BardicFire - Acting Coordinator
* Birchbeer - Contributor
* Gecko - Passive Contributor

Sources:
* PC3 The Sea People
* Real World Ocean Currents
* Approximation based on Sea Routes on Mystaran maps.
* PWA2 Poor Wizards Almanac AC 1011

Link to Main Discussion & Development Thread:
* viewtopic.php?f=21&t=7346
Last edited by BardicFire on Wed Oct 19, 2011 10:25 pm, edited 2 times in total.
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Re: Geo-Informative Maps: Ocean Currents

Postby Havard » Wed Oct 19, 2011 3:03 pm

Looking forward to seeing it!

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Re: Geo-Informative Maps: Ocean Currents

Postby Birchbeer » Wed Oct 19, 2011 4:27 pm

Here is a very very Rough Draft

I don't have PC3 in the office, so here's my best guess. If anyone sees anything amiss please let me know. I also have this rough version in gimp layers if anyone needs it.
Last edited by Birchbeer on Fri Oct 21, 2011 12:47 pm, edited 1 time in total.
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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Wed Oct 19, 2011 7:46 pm

Awesome Birchbeer. I think we need to ask Thorf personally how far out is official ocean on this map we're using.

The only currents in PC3 that are shown are those in the Sea of Dread, which I'll describe here.

Theres the "Great Southern Warm Current" that flows up through the western half of the Thanegioth Archipelago, up towards Ierendi, then across Ierendi and Minrothad, then gets skinny going "under" (south) of the Thyatian Peninsula, finally splitting in two.

There is a "Northern Deep Water Cold Current" that flows from the north, east of Thyatis, underneath the Warm Current, then travels west along the Underwater Terraces, then bending southwest across The Abyss.

I'm looking to see if I can get a image of it to post.

Edit: Here you go - http://fc08.deviantart.net/fs71/f/2011/ ... 4dbncx.png
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Re: Geo-Informative Maps: Ocean Currents

Postby Seer of Yhog » Wed Oct 19, 2011 8:00 pm

The map included with PWA 2 had ocean currents detailled on it, if that helps.
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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Wed Oct 19, 2011 8:23 pm

what is PWA2 Yhog?
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Re: Geo-Informative Maps: Ocean Currents

Postby Cthulhudrew » Wed Oct 19, 2011 8:25 pm

BardicFire wrote:what is PWA2 Yhog?


PWA= Poor Wizard's Almanac. Post-Wrath of the Immortals supplements for the world of Mystara that contained Atlas information, world events, etc.

PWA2 is the AC 1011 Almanac.
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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Wed Oct 19, 2011 8:59 pm

Thanks drew, know anywhere I can download that?
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Re: Geo-Informative Maps: Ocean Currents

Postby Havard » Wed Oct 19, 2011 9:04 pm

BardicFire wrote:Thanks drew, know anywhere I can download that?



Buy a used copy through Amazon for $2.90 :)

http://www.amazon.com/Wizards-Almanac-D ... 560766840/

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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Wed Oct 19, 2011 9:12 pm

Thanks Havard, but even if I had the money to buy it (yes I'm that broke), I want to have a digital copy too. I'm pretty sure there is one on Vaults of Pandius, I know I had one before my Computer Crashed.

Edit: Found it. I love RPGinc. on 4Shared, he's a Canadian Gamer whose basically uploaded EVERYTHING of the old stuff.
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Re: Geo-Informative Maps: Ocean Currents

Postby Seer of Yhog » Wed Oct 19, 2011 9:16 pm

I think that's the one map he didn't do. His site has replicas of the PWA1 (Sea of Dawn) and PWA3 (Alphatia + Esterhold) maps.
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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Wed Oct 19, 2011 9:28 pm

And do those maps have Currents on them Yhog? if so can you link me to them?
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Re: Geo-Informative Maps: Ocean Currents

Postby Gecko » Wed Oct 19, 2011 9:37 pm

Ok, simplified ocean currents 101....

There's lots of factors that drive and direct currents, but most of them are small scale or small effect. I think we'll probably be safe focusing on just some of the big one's.

The monster one is water density gradients. The dominante forces on density is what on earth is known as the thermohaline conveyor (and other similar names). The "-haline" part of the name refers to how salty the water is. Since we don't have any major amazon like rivers dumping tons of fresh water into the oceans at any place, we can probably ignore it (though for anyone interested - there's some interesting theories that at the end of the last ice age, bursting glacial dams pumped so much fresh water into the oceans that it really whacked up oceanic circulations for a long while).

The "Thermo-" part refers to temperature. In large tropical oceans the water recieves more heating from sunlight and gets less dense. It flows into higher lattitudinal colder area's, chilling along the way, getting denser, and eventually sinks, thus creating a verticle loop flowing along the surface away from the tropics, sinking in the high latitudes and flowing cold and deep back towards the low lattitudes.

Density differences are the dominate forces, but yet very few (if any?) earth gyres are solely N-S verticle flowing loops as described, because of the influence of other - albeit less pronounced forces.

The next two, roughly equal (and interrelated forces) are the coriollis effect and and places where there are strong, long lasting, sustained, winds over large bodies of water (ie Trade winds). Sustained winds can eventually cause the surface layer to be blow (flow) away, then deeper (usually colder and denser) water flows up from below to replace it (upwelling). The locations and directions of such winds are caused (in part - I'm simplifying here) by the coriollis effect on the atmosphere, and then the coriollis (I think I'm spelling it wrong) force acting on the water (rather than on the atmosphere as above) then serves to amplify and further drives the direction of flow caused initially (mostly) by the winds. On earth winds flow (generally) in certaint directions at certaint latitudes (see Hadley cells, Trade winds, doledrums, etc. for more). It's where those winds occur over large bodies of water that cause the interactions that help direct the great oceanic clockwise and counterclockwise gyres. On Mystara the bodies of water are in different locales so we might need to check if those differences would effect anything.

Likely the only other factors large enough for us to consider is ocean depths, subsurfarce contours and locations and shapes of landmasses - but that's getting into smaller scale stuff and there's too many variables for a brief (it started out brief, I promise It did :oops: ) overview.

Of course lots of other factors play a role in RW currents (ie Tides) but I think we can ignore them for our purposes. Though you do also need to think about how currents and gyre's interact and shape one another. ie Two adjacent gyres - one clockwise and one clockwise) can drive each other like interlocked gears - though you can also get countercurrents, or ie2 one current flowing into another (like through a straight) can influence or even create another in the adjacent body of water.

Once we get those things sorted out, that will help determine which currents are surface vs. deep (In the deep oceans remember to think about them existing in 3 dimensions! Most gyres are 3-D conveyor belts somtimes creating twisted figure-"8" shapes), and which one's are warm vs. cold should also then become apparent.

Seer of Yhog wrote:The map included with PWA 2 had ocean currents detailled on it, if that helps.


I thought I had seen that info somewhere. I'll have to dig my PWAs out. Is it discussed in the book itself or just on the map (I think I stored the map seperately - but won't know till I go digging)
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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Wed Oct 19, 2011 10:06 pm

AND heres the map from PWA2: http://fc09.deviantart.net/fs70/f/2011/ ... 4dbzjg.png

Thanks Gecko for all the info, May I add you to the Team? (see first post)
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Re: Geo-Informative Maps: Ocean Currents

Postby Gecko » Wed Oct 19, 2011 10:15 pm

Looking at the PC3 map and trying to extrapolate to the sea of Dread as a whole, might the sea of Dread have two mini-gyres? The PC3 map shows the surface warm current flowing north ward towards the malpheggi, then flowing eastward filtering through the isles. Wouldn't that also drive another lobe flowing weastward towards Sind?

Extrapolating that deep cold current, I would figure it either
A) upwells somewhere off davania, OR
B) continues on into the Izondian Deep

From that draft map- Is there anything in Cannon saying that it's a clockwise flow in the Izondian Deep? One the positive side it would help explain why there is little to no direct sea trade between the Known World and the Savage Coast (though a season wind shift, ie monsoon winds would make sailing that way easier - ocean current directions help with sailing, but wind direction is more important that ocean currents for sailing considerations), but on the other hand it doesn't "feel" right, for a reason I can't quite put my finger on - unless that's one hell of a counter-current you have going through the Straight of Izonda.
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Re: Geo-Informative Maps: Ocean Currents

Postby Gecko » Wed Oct 19, 2011 10:19 pm

BardicFire wrote:Thanks Gecko for all the info, May I add you to the Team? (see first post)


I'll pop in from time to time. I'd love to sit down and go through all this in great detail, but I just don't have the time (and it's hard to download and upload maps on a dial-up 'net connection). I've already spent too much time today on this.

cheers,

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Re: Geo-Informative Maps: Ocean Currents

Postby Birchbeer » Thu Oct 20, 2011 2:14 am

Concerning the map I think there is atleast one issue with it.. the ocean current going north along the western side of the Serpeant Peninsula is wrong. If the Corealis affect is working properly it should go clockwise (like it does in the sea of dread).

I have a hunch that someone somewhere at TSR made a master currents document, as this looks extrapolated from a master map (or atleast idea). I wish I could see it.

Another thing I noticed is with Alphatia gone I'm thinking that the currents would be different, vastly different than with it there. This confirms what I suspected... Before Alphatia sinks the coast of Skothar facing Alphatia was warmer, given that the current would hit Alphatia, go around Alphatia onto the coast of Skothar. After the sinking of Alphatia that current no longer goes that way, instead it would go towards Brun, intercepting a polar current, then going to Skothar with much cooler water. In other words... Western Skothar may have gotten cooler. Norwold and the great bay got warmer after Alphatia sank. (Please double check my thinking on currents as I maybe off... :)

Edit: Fixed map as the link was incorrect.
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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Thu Oct 20, 2011 3:03 am

Your link doesn't work Birchbeer, so I don't know exactly what you're talking about, but I think you mean the large map. But based on everything you're saying here, I personally think we should probably make at LEAST 4 maps:

1. Map accurate to Resources we have, Pre-Alphatia Sinking
2. Map accurate to Resources we have, Post-Alphatia Sinking
3. Map accurate to how currents really work, Pre-Alphatia Sinking
4. Map accurate to how currents really work, Post-Alphatia Sinking
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Re: Geo-Informative Maps: Ocean Currents

Postby Birchbeer » Thu Oct 20, 2011 10:56 am

BardicFire wrote:Your link doesn't work Birchbeer, so I don't know exactly what you're talking about, but I think you mean the large map. But based on everything you're saying here, I personally think we should probably make at LEAST 4 maps:

1. Map accurate to Resources we have, Pre-Alphatia Sinking
2. Map accurate to Resources we have, Post-Alphatia Sinking
3. Map accurate to how currents really work, Pre-Alphatia Sinking
4. Map accurate to how currents really work, Post-Alphatia Sinking



That sounds good to me, we need to dig up a map that involves just Brun, Skothar and the land in between (along with some of the north of Davania).

The draft I did of the currents should be fairly accurate per Earth's model of currents. About the only thing missing is more of a equatorial counter current south of Skothar (Earth does that and it's kind of weird given the currents above/below the equator move in the opposite direction). It is entirely possible that Mystara has some magical "fun" with currents and weird things can pop up.
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Re: Geo-Informative Maps: Ocean Currents

Postby Birchbeer » Thu Oct 20, 2011 3:23 pm

For the Alphatia project, I'm believe this is the best map of the area map.


To do the post sinking I'll just superimpose this map over it.

The first thing I'll do (later today or tomorrow... in a time crunch right now) is to create the secondary map of Alphatia being sunk. Then I'll aim to try to draw the currents based off of the earlier map we have of the currents for the Known World.
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Re: Geo-Informative Maps: Ocean Currents

Postby Seer of Yhog » Thu Oct 20, 2011 4:57 pm

This is amazing. Just think about how LONG this sort of work would have taken without the advent of high-speed Internet, advanced scanning, and graphics programs. Considering that map from PWA2 is what I used to start my old map of Davania...wow.
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Re: Geo-Informative Maps: Ocean Currents

Postby Hugin » Thu Oct 20, 2011 8:32 pm

While looking into ocean currents and how they might look on Mystara, I first wanted to confirm where the various lines of latitude cross the Mystara map. Unfortunately, and it really shouldn't be a surprise, I couldn't do this.

Even the PWA II contradicts itself on where the 30°N latitude should be. On the chart it says Thyatis City lies at about 30°N, while the map places it at ~40°N. The chart says Tanakumba (Yavdlom) lies at 20°N, while the map shows it at 15°N. Basically, the chart would have twice the distance between Tanakumba and the equator than there is between it and Thyatis. The map on the other hand, completely reverses that and says there is twice as much distance between Tanakumba and Thyatis as there is between it and the equator.
[To state the relationship more clearly, if the equator = 0 and Thyatis = 3, the chart says Tanakumba = 2 and the map says it = 1]

The Outer World map from the HW set agrees with PWA II's map on the placement of 30°N latitude, as well as (more or less) the equator, Thyatis, and Tanakumba. If this is taken as (more or less ;) ) correct, a single 72 mile hex represents 1.2° of latitude. That matches very well with this map when I checked for distance compatibility.

This means that Mystara is slightly smaller than Earth; 0.86 times the size of Earth. Here's the interesting coincidence though, on Mystara, one mile equals one second (i.e. 1/60th) of one degree of latitude (otherwise stated, 60 miles equals one degree of latitude). So a Mystaran mile works the same as our nautical mile. This makes the circumference 21,600 miles around, close to the HW map's stated 19,448. [Note that this makes seven and a half 8-mile hexes represent one degree of latitude.]

Based on this I am going to do some further hex counting on various maps to see what kind of latitudes this produces for other locales. I'm post what I find once I find it.
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Re: Geo-Informative Maps: Ocean Currents

Postby Hugin » Thu Oct 20, 2011 9:23 pm

Well, I'm not so sure how well this works out. Things may work nice for the lower 45° of latitude, but the Alphatian map then has so much distance as to put Farend at 75°N and the Arctic Circle at Alphak's Volcano (Island), claiming the Great Bay in it's domain. A bit too far north perhaps?
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Re: Geo-Informative Maps: Ocean Currents

Postby Gecko » Fri Oct 21, 2011 2:03 am

Birchbeer wrote:Concerning the map I think there is atleast one issue with it.. the ocean current going north along the western side of the Serpeant Peninsula is wrong. If the Corealis affect is working properly it should go clockwise (like it does in the sea of dread).


Thats the same one I was refering to, it seems odd, either wrong or needing an explanation. Though on the other hand, the Corealis effect (I realy should look up how to spell that properly) can be overpowered by other factors (ie in the North Pacific you've got Gyre's going in both directions - the clockwise Subtropical Gyre and the weaker counter-clockwise Subpolar gyre)

Another thing I noticed is with Alphatia gone I'm thinking that the currents would be different, vastly different than with it there.


YES. the question is how deep is the new Alphatian Ocean? I figure it's pretty shallow overall. And you've still got most of the mountains above water in the NW spine.

birchbeer wrote:That sounds good to me, we need to dig up a map that involves just Brun, Skothar and the land in between (along with some of the north of Davania).


Perhaps LoZompatore's map? I've seen a version without all the names somewhere, and a draft one covering Davania.

About the only thing missing is more of a equatorial counter current south of Skothar (Earth does that and it's kind of weird given the currents above/below the equator move in the opposite direction).


I'm not 100% sure what forces & factors create/drive a counter-current (it's something I need to look into), but just because Earth has one's (and I think they are relatively weak) doesn't mean there is neccessarily one's on Mystara. of course doesn't mean they don't either.

It is entirely possible that Mystara has some magical "fun" with currents and weird things can pop up.


definately.

Hugin wrote:While looking into ocean currents and how they might look on Mystara, I first wanted to confirm where the various lines of latitude cross the Mystara map. Unfortunately, and it really shouldn't be a surprise, I couldn't do this. Even the PWA II contradicts itself ...


Hasn't this problem come up before? It seems to also vary based on what map projection is used or something, right?

Of course we have standardized and universally divided-up the globe of our world's lattitude and longetude (man my spelling is attrocious today, my apologies :facepalm:) into 60 seconds, 60 minutes, and 90/360 degrees based on an inheritance from Bablyonian mathematics. Maybe in-character mystaran cartographers have two (or three) competing systems (ie Thyatian vs. Alphatian, or something), especially when you add in the complexeties of the polar openings (ie is 90 degrees considered in space in the middle of the polar openings? The smallest diameter rim? edge of the outerworld darklands? what/where?)

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Re: Geo-Informative Maps: Ocean Currents

Postby BardicFire » Fri Oct 21, 2011 3:29 am

Remember I want to keep Hex and colourings to Thorf's style so it fits into the Atlas, but this is great work guys, sorry I can't be more hope, but hey, Being Coordinator has gotta be somewhat helpful.

I was reading PWAII, and it directly states the diameter of The Outer World. is this contradicting by any LATER info, because I say the "newer" the released information the higher it's information should be recognised (prioritised)
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