Faithful reader Norah writes: "I read in the paper this week about the disappearance of woolly mammoth and other large-bodied animals at the end of the Ice Age, and how the disappearance happened earlier than first thought. How does this affect what we understand about pre-clovis? Is this support for the presence of humans in North America before Clovis?"

Vinland is the name of the legendary place described in the Viking sagas that was said to have been founded by Leif Ericson on the North American continent. But its connection with the Viking archaeological site in Newfoundland called L'Anse aux Meadows is fraught with controversy. Canadian archaeologist Birgitta Linderoth Wallace has studied L'Anse aux Meadows for the past forty years, and has developed some interesting notions about that precise issue. Wallace's work, published primarily but not exclusively in the 2006 book Westward Vikings: The Saga of L'Anse aux Meadows, isn't often cited, but in my considered opinion, should be.

This woodcut showing Erik Bloodaxe's widow Gunnhild Gormsdóttir inciting her sons to take possession of Norway is from Erik Bloodaxe's Saga, as it was published in Snorre Sturlassons's Heimskringla in 1235. Although Erik Bloodaxe's Saga isn't part of the Vinland sagas, it's one of numerous other Viking sagas. Image uploaded by Christian Krogh

During the first studies at L'Anse aux Meadows in the 1960s, the original excavators rather overdid their reliance on information provided in the Vinland sagas. The Vinland sagas are four manuscripts written in the 11th-13th centuries AD, which describe the adventurous ramblings of the Norse in Iceland, Greenland, and the North American continent. Relying on any historical record for archaeological evidence is dicey, even if the records are confirmed to be authentic manuscripts. The Vinland Sagas are not factual records. They're legends, written down decades or centuries after the described events, and as such they can't be trusted to contain "just the facts". That certainly wasn't the writers' intent: they intended to tell a good story, to glorify an ancestor, to keep the ancient legends alive, or some other intention now lost to the ages.

The early over-reliance on the Viking sagas as fact led later scholars to ditch the sagas as completely untrustworthy; some dismissed the discoverer Leif Ericson as a literary myth. But Wallace bravely cracked open the sagas again, and combining archaeological evidence and historical records has discovered some fairly interesting things, particularly about what Vinland might have meant and whether L'Anse aux Meadows can be tied to a specific place named in the Vinland Sagas.

Read More about Vinland

• Where is Vinland?
• The Vinland Sagas
• L'Anse aux Meadows
• Guide to the Viking Age

Wallace, Birgitta Linderoth. 2006. Westward Vikings: The Saga of L'Anse aux Meadows. St John's, Newfoundland: Historic Sites Association of Newfoundland and Labrador in association with Parks Canada.

Wallace, Birgitta Linderoth. 2003. L'Anse aux Meadows and Vinland: An Abandoned Experiment. Pp. 207-238 in Contact, Continuity, and Collapse: The Norse Colonization of the North Atlantic, edited by James H. Barrett. Brepols Publishers: Trunhout, Belgium.

I admit right up front that I haven't seen the video "Deep Secrets: The Ballard Gallipoli Expedition", because it wasn't made available to us journalist types prior to the program, which airs on the National Geographic channel Wednesday November 18th. All I know for sure is what is in the press kit.

AE2 Wreck from Underwater at Gallipoli, Turkey. Photo (c) ProsperoPTY Ltd/NGT/Screen Australia/Screen West, Inc.

However, by poking around on the Internet, I have discovered some information on the wreck illustrated in the photograph provided—it is the wreck of a Class E Australian submarine scuttled during the Battle of Çanakkale, on April 30, 1915. HMAS (His Majesty's Australian Ship) AE2 was identified in 1998 by an Australian team led by Mark Spencer; perhaps one of the topics discussed include new discoveries about that. Anyway, see the Reader's Guide to Expedition Week 2009 for what I was able to come up with.

• Bob Ballard at Gallipoli, including what resources I could find that relate to the story
• Deep Secrets: The Ballard Gallipoli Expedition, from National Geographic

On Tuesday, November 17, 2009, National Geographic's Expedition Week presents a new video documenting the underwater archaeology discovery of three imperial Japanese submarines, all scuttled by the American forces off Oahu in 1946.

CGI Image of the I-201 Fast Attack Japanese Imperial Navy Submarine. Photo credit: (c)Wild Life Productions

"Hunt for the Samurai Subs" is entertaining and educational, and contains lots of interviews with members of the Japanese and American navies, as well as 1946 footage from one of the American servicemen who watched some of the purposeful scuttlings of the unmanned ships.

This is the kind of stuff that I like to see from National Geographic, well-researched, with interviews from the people concerned and lots of context. Several CGI images of what the subs would have looked like help understand the technology, and the search techniques are explained and illustrated well.

Read my full review and see a couple of additional photographs in National Geographic Expedition Week 2009: Hunt for the Samurai Subs.

• Hunt for the Samurai Subs: A review and two more photographs
• Hunt for the Samurai Subs on National Geographic Week
• Hawai'i Undersea Research Laboratory (HURL) on Samurai submarines