# How would ocean currents work with a gulf that's closed to the equator on both sides?

I'm running a D&D campaign and am using a modified map of Venus for it that shows what Venus would look like with similar amounts of water to Earth. The problem I'm running into is mapping the ocean currents around the equator at this point of the map where a centrally based gulf has land on either side of the equator. Would it still create an equatorial counter current? The other problem I ran into was how this ring of land would affect ocean currents within it. Would it rotate within itself or would it be more likely to force itself through the small waterways around it? This is the gulf causing me issues.^ This is the ring.^ This is the globe as a map to give better context.^

• A few clarifying questions - first, you’ve inverted Venus’s normal north-south axis, placing Ishtar Terra and Maxwell Montes in the south. Does the planet still spin from east to west, or is the direction of spin also reversed (and therefore now aligned with the rest of the solar system)? Second, the basin is about 1000 kilometers across, yes? I can’t find a good scale bar but size will change ocean currents significantly. Finally, how deep do you imagine this basin will be? It’s hard to tell from the Venus topo maps I’ve found - somewhere less than 1km and more than 100m? Mar 23, 2019 at 5:31
• @Dubukay I flipped it because the majority of the continuous land mass around the equator appears to be in the southern hemisphere. Seeing as that's where I figured society would advance the fastest, I figured they'd put themselves at the top of the map. This would probably flip the direction of the currents, seeing as it's just changing the orientation and not the actual properties of the planet. as for the basin, 1000km looks accurate. I'll say its deepest point could be 650m. Mar 23, 2019 at 10:47
• @Dubukay You can't simply use a topographic map of Venus to figure out ocean depth. In the Paper "Terraforming Venus quickly" it is mentioned that even the condensed CO2 atmosphere (less mass than the Earth like oceans OP wants) would cause significant tectonic changes. With the oceans mass collected in the basins, they will get deeper and the highlands will rise. Mar 23, 2019 at 11:20
• @TheDyingOfLight that’s why I asked :p Mar 23, 2019 at 14:54
• @Jokerhr: This question may receive more attention at Earth Sciences: earthscience.stackexchange.com/questions. If so the policy says to link your question at ES to this question, not duplicating content.
– user61971
Mar 23, 2019 at 15:46

As Venus rotates in the opposite sense of other Solar System planets, the equatorial current would flow from West to East. As you turned down the map, it would flow from rigth to left as on Earth's maps.

Coriolis force would create on the Gulf, placed at Northern Hemisphere on Venus, a counter-clockwise sense superficial current as on Southern Hemisphere on Earth, so it could create a countercurrent. My guess is it will create it.

The sea at the left of your map you named ring at the weastern whould be a Thetys type Ocean, named in Oceanography also Mediterranean Seas.

Superficialy Coriolis force would create short basins. At Earth major currents surrounding the landmasses take place in counter-clockwise sense, but this is also related other factors:

Source: researchgate.net

At your sea I would expect, as it is placed at Northern Hemisphere, to have a main current flowing as at Southern Hemisphere on Earth, counter-clockwise:

In depth mediterranean currents are dominated by convection from the surface to the seabed:

Source: M1 Oceanography notes. University of Bordeaux.

At the Strait of Gibraltar that deep water flows over the vast ocean, interacting with its deep water. That's what would happen at your sea as, if I am not wrongly interpreted your map, it is partially open at the West. Here the sense of rotation would not take effect, as your sea should have more salinity than the ocean and deep circulation is thermohaline.

Source: pinterest.es

The replacement of water would create an input current, resulting for the closed sea:

• Very nice use of images. well done! Mar 23, 2019 at 13:39
• I don't know about your statement on the Coriolis force. In your image you have circulations that contradict it; the current west of Sardinia and the currents south of Spain. Mar 23, 2019 at 17:10
• @Ryan_L My english is poor but what goes in counter-clockwise are major currents paralel to the landmasses. At little basins as you mention they sometimes flow in the other sense. I change circles for currents I think saying circles is ambiguous. Better?
– user61971
Mar 23, 2019 at 17:12
• Yeah I think so. Mar 23, 2019 at 17:21