Monday, March 11, 2019

Antarctic Voyage 2019 - Part 3 - The Antarctic Peninsula

Finally! On our way to Antarctica. But as we rounded the east end of South Georgia Island, we encountered Beaufort 10 winds - at our back. Fortunately, this was not as bad as if we would have had to charge into it.

An example of the wake given off as our ship plied the Southern Ocean waters. Note the large tabular iceberg in the fat distance. The height of that ice cliff is 200 feet, meaning that the height of the iceberg including the submerged portion is about 1,800 feet! The Captain told us it was about 16 miles long. That is one large iceberg.

Location map showing the South Shetland Islands, Bransfield Strait, and two volcanic islands - Penguin and Deception - that we visited on this voyage.

We arrived early to Antarctica and were able to make a late afternoon landing on Penguin Island. You can see by its shape that it might be a volcano and in fact it is a scoria (cinder) cone. The ramparts along its edge are lava flows that issued from the base of the cone in the waning stages of its eruptive cycle.

Once ashore, the scoria and basalt lava is obvious. This cone has been active in last few hundreds of years.

This is a panorama shot of the summit crater taken with the Pano function on the iPhone 7 Plus. While it may look as if I just cropped the bottom and top of a normal photo, you can see that the view of the crater is far too wide to capture that way.

This is a close-up of the crater area showing a possible vent on the left (differential erosion casing it to stand higher than the loose scoria that surrounds it) and a resurgent crater on the floor of the larger crater. Wow! I love Penguin Island - except the name! There are zillions of islands with penguins on them but only a handful of scoria cones. How this one got the name "Penguin" is beyond me!

From the summit looking north to the north end of King George Island, the largest island of the South Shetland chain and covered in glacial ice. Le Lyrial is anchored offshore in the brilliant late-afternoon light. Our ship carried about 165 passengers on this voyage, 19 staff members and about 130 crew members. I was working for Abercrombie and Kent, who chartered the ship from a French company Ponant. There is a three minute promotional video that shows much of what happens on these voyages here. I provide this mainly for the wonderful images of the landscape and not so much for the great food that is featured - the lecture program is only touched upon briefly by the narrator.

A wider view from a slightly different vantage.

On the beach is a nearly complete skeleton of a whale with numerous Chinstrap penguins for scale. Ohh - that is how the island received its name!

The January 26 sunset from Penguin Island, Antarctica.

Rockscape from Half Moon Island. I saw a variety of extrusive and intrusive  rocks here. This part of Antarctica shows evidence similar to much of the western Americas with Mesozoic subduction leading the arc volcanism and plutonism. Similar to what is found in the Sierra Nevada of California and the Andes in South America.

Map of Deception Island showing our route into the narrow entrance of the caldera called Neptunes Bellows and our hiking destination at Telefon Bay.

Wide-angle view of Neptunes Bellows. The channel inside is quite narrow and at least one ship wreck was observed on the opposite shore from the pre-tourist era.

Hiking up to the crater formed in the 1970 eruption. Port Foster with Le Lyrial in the background.


Looking in the opposite direction, a glacier has entered the crater and partially obscures it.

Larry Hobbs, our cetacean expert and lecturer admires the contrast between fire and ice!

Close-up of the glacier wall showing internal deformation of the ice and vertical cracks (called crevasse) where scoria has filled them. This is a very dynamic setting with ice flowing constantly and material being blown into cracks in the ice.

Note the once laminar horizons in the ice that are now deformed into chevron folds as the ice flows downhill into the crater.

Another Pano shot, this time of our iceberg expeditions in Zodiacs near Cuverville Island. I also drove Zodiacs for our guests.

The dark water absorbs heat when the sun is out, causing a melt line to develop at the water line in the iceberg.  When low tide causes the bergs to become grounded, they tilt and expose these melt lines.

Another melt line is 'uplifted' during a low tide stranding. This one reveals a monolith through the arch.

As the bergs melt and break apart, their center of gravity changes and they can roll and flip at a moments notice. Zodiac drivers approach large icebergs at their peril and like pilots, there are old Zodiac drivers and there are bold Zodiac drivers. But there are only wet old and bold drivers!

The shapes can be quite fantastic!

A portion of the submerged part of the iceberg can be seen here in this shot from our cabin balcony, about 50 feet above the water line. This is in the Ererra Channel with the Antarctic mainland in the background.

A Weddell seal (Leptonychotes weddellii) lies in repose at Neko Harbor on the Antractic Peninsula.

Gentoo penguins (Pygoscelis papua) lie on their rock nests at Neko Harbor.

The sun was trying to break through this afternoon and I thought it might...

...but instead the clouds became progressively thicker. This was the first time I had been shut-out from a transit of the Lemaire Channel in all my 26 trips to the Peninsula.

These are the intrusive rocks that underlie the entire Peninsula and are Mesozoic granites and similar rocks. They form the heart of the arc with the erupted volcanic material eroded off of them. This is at Port Charcot near the Le Maire Channel.

Some more iceberg photos.



A Leopard seal (Hydrurga leptronyxnaps on a bergy bit.

Our Expedition Director, Suzana Machado D'Oliveira, standing with us on the bridge of Le Lyrial. This was a wonderful cruise with a fantastic staff! I can't wait to return!

3 comments:

Toni Kaus said...

Thanks for all three posts. Loved them!

Donald Ranney said...

Nice trip! Lot's of ice. Is there less than when you were last there? Nice to see Susanna. Changed some!
Love, Dad

Toodles said...

Joe and I loved seeing these photos AND the video at Frank's. Thank you!