Natural Phenomena

[espross]

USS Shenandoah, 18 October 1879, afternoon watch, in squally weather at about 36 N 50 W (p. 52), encountered a water spout:

[Randi]

[espross]

USS Shenandoah, 1879, October 29, p. 63.

The ship is just two days from catching the NE trades after almost three weeks' slow progress ESE from New York when the logkeeper notes,

Passing quantities of floating seaweed during this watch

I think it's safe to say the seaweed they encountered was Sargassum. I dropped an 1891 map of the Sargasso Sea onto Google Earth and plotted the ship's position that day.



Sargassum is a genus of brown algae comprising about 150 species worldwide, but the Sargasso Sea is characterized by two free-floating species, S. natans and S. fluitans. Unlike the others, these two are "holopelagic," reproducing and growing entirely at the sea surface. Growing in enormous mats, they provide the basis for an enormous variety of pelagic life.


(National Geographic, "Life in the North Atlantic Depends on this Floating Seaweed")

When it comes ashore it can be a nuisance--and with a warming climate, deforestation and fertilizer runoff it seems to be overgrowing in the past decade. Indeed it has inundated tourist beaches throughout the Caribbean and Florida to the extent that there are numerous Sargassum trackers.


(Yucatán Magazine, "Sargassum returns: Unsightly algae returns to the Riviera Maya")

The Sargasso Sea lies at the heart of the North Atlantic Gyre, whose currents the USS Shenandoah was riding in order to speed its passage to Rio de Janeiro. As we have come to understand, these oceanic gyres concentrate not just seaweed but flotsam of all kinds. Indeed, the first scientific observation of oceanic microplastics was from a 1971 voyage to the Sargasso Sea. Marine biologist Ed Carpenter and his team published their findings in Science in March 1972, predicting a worrisome future:

Increasing production of plastics, combined with present waste-disposal practices, will undoubtedly lead to increases in the concentration of these particles. Plastics could be a source of some of the polychlorinated biphenyls recently observed in oceanic organisms.

Strangely, this research was shelved until the mid-1980s, when (in a bit of Old Weather serendipity) researchers aboard a tall ship began making annual plankton trawls from Woods Hole MA to St Croix VI, and were able to plot microplastic concentrations in the North Atlantic subtropical gyre.


(see Laws et al., 2010.)

Strange to think that USS Shenandoah didn't encounter any plastic at all!

[Randi]

Fantastic research job!

[Michael]

It looks like someone went down a rabbit hole!!!

Very interesting, and very cool!!!

[arboggs]

Great work, espross, really fascinating.

[Michael]

March 10, 1888
8 PM : Lat 11° 32' 00"N, Long 99° 20' 00"W

8 PM to Midnight

Observed large & brilliant meteor in the S.E.

[Randi]

On the subject of sargassum....

A Giant Blob of Seaweed is Heading to Florida
The mass, known as the great Atlantic Sargassum belt, is drifting toward the Gulf of Mexico.
Scientists say seaweed is likely to come ashore by summer to create a rotting, stinking, scourge.

[espross]

This year’s sargassum bloom is making quite a bit of news, partly because it is likely to be another record breaking year, and it will jeopardize tourism throughout Florida and the Caribbean.

This bloom is not really part of the Sargasso Sea; rather, it’s a new belt extending all the way from the African coast to the Caribbean, 8850 km long.

One article I read said that blobs of it that used to be record-breaking would no longer even register on the charts because they’re too small.

https://www.npr.org/2023/03/15/11633851 ... co-beaches

https://amp.theguardian.com/us-news/202 ... um-beaches

[Michael]

Wow!!!

[Morgan]

On the west coast of the USA, we have beach cleaners that are a cross between a wheat combine and a street sweeper. They comb through the sand and gather and contain trash. But these are real sandy beaches without plant life or much of animals. There is also a boat that skims the harbor surface. It seems one could skim the floating blob and turn it into compost something. I know, however the blob is nursery and habitat; so I would likely be making things worse. UGH.

[joke_slayer]

From Yantic 1867-11-01 at Tampico

2155 Saw a meteor bearing W by N moving rapidly through the sky lighting up the heavens around it brightly

https://s3.amazonaws.com/NARAprodstorag ... 7_0104.JPG

[joke_slayer]

Yantic 10 Dec 1867

0000-0400 Commences with clear sky veiled over so that but a small portion of stars were visible
Observed a circle around the moon, gradually increasing in diameter till 2 when its observed semidiameter was 22 23', the inner edge of the circle being especially well defined. After 2 the circle gradually disappeared and the sky clouded over with cirrs cumuli and cirrs strati.

https://s3.amazonaws.com/NARAprodstorag ... 7_0143.JPG

[Randi]

[espross]

Amazing, and amazingly enough, there is an atmospheric phenomenon known as a 22 degree halo that may fit that description.

https://en.m.wikipedia.org/wiki/22°_halo

The mechanism of their formation is not entirely understood, but it seems to have to do with hexagonal ice crystals contained in cirrus or cirrostratus clouds, which can precede foul weather.

[Michael]

[ggordon]

Aboard the Shenandoah on December 17, 1873 roughly 200 miles west of Casablanca, Morocco:

8PM to Mid

Noticed a very brilliant meteor traversing from the North to the South.

https://s3.amazonaws.com/NARAprodstorag ... 28-036.JPG

[ggordon]

Aboard the Shenandoah on December 28, 1873 off the West Coast of Africa

2:45AM

A brilliant meteor appeared about 20° North East of Sirius. It travelled about 30° in a Southerly direction and disappeared. The duration of its illumination was about 2 seconds, the light being of a clear blue, so intense as to enable faces to be distinguished the length of the ship and giving the appearance of leaving a trail.

Noon location of the ship was Lat 20° 52' 00" N Long 31° 00' 00" W. At 2:45 AM the ship was roughly 50 knots to the East of the Noon position.

https://s3.amazonaws.com/NARAprodstorag ... 28-047.JPG

[Randi]

[Michael]

11 August 1865
Near 51N 8W

8 PM to Midnight

Observed a number of meteors during the watch.