The greatest visual distance between two points on Earth

Factual Questions
1

Inspired by this GQ thread.

What are the two points on Earth that you can stand on either one and see the other point which has the greatest distance between them than any other pair of points on Earth? Assume that you can see the other point on a clear day. For example, Mt. Everest might be a good starting point (believe me, I am a Yeti!) and looking outward to other Himalayan peaks a couple hundred miles away, but there are likely other mountains closer that would block the view of the other peak. In other words, consider the line of sight on the horizon when testing two points. That might lead to the possibility of two islands with high peaks that have greater distance because the horizon might likely be the ocean (sea level)…or it could be a combination of the two.

There are probably quite a few pairs that are over 200 miles; 300 miles might be closer to the actual limit.

Do consider the seven summits. Especially those that you can see the ocean and vice-versa.
Mountain Ranges like the Andes…close to the ocean with islands off the coast might be another possibility.
Another site proposed the Wrangell Mountains in Alaska and Denali NP (Mts. Blackburn and Foraker) at 270 miles, but not confirmed and challengeable.

And Cecil…if you are out there…chime in! (Or did he do this already?)

2

This website may answer your question.

3

From your cite, here is a possible winner…

And here I thought it was going to be Pike’s Peak to the Canadian Boarder…:rolleyes:

4

I’ve read several times that the summit of Mt. Whitney in California can be seen from the summit of Telescope Peak in Death Valley. Might be BS, though—it seems that the White Mountains would be in the way. That’s a pretty respectable distance though, if it’s true.

5

Actually, Mt. Whitney to Telescope Peak is only 73 miles, and the White Mountains (in the 3rd panel) and don’t interfere with that sight line. What’s more impressive though is that you can see Mt. Charleston (just a little north from Telescope Peak) from Whitney which is double the distance at 146 miles, and also from Mt. Whitney, you can see San Gorgonio at 190 miles. I also note that you might be able to make out Loma Prieta from Whitney at 200 miles, but it would be hard to discern.

My town is about 3/4 of the way in that Mt. Whitney to San Gorgonio sight line…tucked behind that red ridge in the diagram next to the picture.

6

Yeah, I know—I went and looked it up too. I thought it would have been way more than that, considering how long a drive it is to each from Los Angeles.

7

Maybe we should break this down into two separate categories…

Longest observable straight line distance (photos or seen by many). ATM, it seems to be Denali and the Wrangell Range at 220+ miles.
Longest theoretical straight line distance (computer generated topography). ATM, it seems to be Paramillo and Pico Christobal at 300 miles.

8

My first guess would be between the summits of two volcanoes. Is it possible (in theory) to see the summits on the Hawaiian Islands?

9

from Sarah Palin’s house to Russia, obviously.

10

I don’t remember specifically, but I’m pretty sure there are places where you can see one Hawaiian island from another. I’m pretty sure I’ve seen one island from another, such as Mauna Loa/Kia on Hawaii from Haleakela on Maui. Those would be pretty easy to figure out, though, so I doubt they’re anywhere near record-holders.

11

Haleakela to Mauna Kea is 75 miles…I’ve personally seen both from the other’s summit.

I did a little work to find that the distance from Mauna Kea (Big Island - 13,796 ft.) to Kawaikini (Kauai - 5226 ft.) is 303 miles, but the sight line limit with their elevations is only 232.5 miles. So…not a contender.

Both peaks would have to be about 15,300 ft. in elevation to be theoretically visible to each other at 303 miles.

12

Mt. Kilimanjaro has a tremendous overview of the plains for quite a way around.

13

I guess this opens up an auxiliary question. What place on the earth’s surface enables a viewer to see the greatest unobstructed land (or ocean) area?
Himalayas are obvious non-contenders since there are big mountains blocking the view in different directions. Kilimanjaro is a real possibility due to its elevation and the relative flatness of the surrounds.

14

Mauna Kea would be another contender here, standing 13,803 feet high in the middle of the Pacific Ocean.

15

In the other direction, I have clearly seen the summit of Kilimanjaro from Mount Kenya, rising above the low cloud/fog over the plains at sunrise. According to Google Maps that is almost precisely 200 miles.

I’ve tried to find a photo of that view on Google Images, but no luck yet. This one claims to be, but looking at the shape of the mountain it looks more like Mt Kenya from Kili to me.

Edit: here’s one.

Less impressive distance-wise, but more impressive visually, I’ve seen Mount Taranaki from Mount Ngauruhoe in New Zealand, a distance of 85 miles.

16

Here’s a good thread with photos on a different forum.

And a previous Dope thread, started by a particularly erudite poster.

17

(wrong thread, sorry)

18

I have a very clear view of Mount Fuji from my office, 160 km (100 mi) away. Whether the mountain is visible depends greatly on the weather. When a high pressure front comes by, it looks like I could just walk over to the mountain, whereas on an even slightly misty or hazy day, it’s completely invisible. I assume that the surrounding weather may be a factor to consider. People I known who have gone to Baffin Island told me how difficult it was to judge distances as faraway mountains looked much closer than they were.

19

There’s a nice photo here taken from Bosnia, showing several peaks ~200 miles away in Italy, with the Adriatic Sea in between. The most distant is 330km (205 miles).

Quite impressive given that it was only taken from a peak barely over 2,000 metres.

20

Here’s another fairly recent SDMB thread on the subject.