Well, that’s one way to visualize the rate of continental drift.

Marie Tharp is the subject of today’s Google Doodle, with an interactive narration of her life story. That story—how Tharp’s pioneering work mapping the ocean floor helped prove the theory of continental drift—is familiar to long-time readers of this blog: this is the 12th post I’ve made about the legendary cartographer. But someone is going to be one of today’s lucky 10,000 because of this, and that’s not a bad thing.

Ortelius was a Google Doodle in May 2018.

Pretty amazing full plate tectonic animation of the last billion years from @AndrewMerdith – Merdith et al. 2021 (Earth Science Reviews) @MullerDietmar @EarthByteGroup @UniAdelSciences https://t.co/Plne1y1Qm7 pic.twitter.com/IIFGRaZ3vD

— Alan Collins (@geoAlanC) January 29, 2021

It shows the movement of Earth’s tectonic plates over the past billion years, and it was posted by one of the co-authors of this study proposing a new, single model of plate tectonic activity that covers the past billion years of Earth’s existence. (Previous models, if I understand the abstract correctly, covered shorter periods—for several-hundred-million-year values of short—and didn’t line up with each other.)

The Ancient Earth Globe is a virtual globe that depicts the Earth of the distant past, with continents and oceans rearranged. Created by Ian Webster, it uses map data from the PALEOMAP project. [Strange Maps]

The anniversary probably explains why two books about Tharp, aimed at children, are coming out this year:

Ocean Speaks: How Marie Tharp Revealed the Ocean’s Biggest Secret
by Jess Keating
Tundra Books, 30 Jun 2020
Amazon (Canada, UK) | Apple Books | Bookshop


Marie’s Ocean
by Josie James
Henry Holt, 22 Sep 2020
Amazon (Canada, UK) | Apple Books

Add those to Robert Burleigh’s Solving the Puzzle Under the Sea: Marie Tharp Maps the Ocean Floor (2016), also aimed at young readers, and Hali Felt’s 2012 biography of Tharp (for adults), Soundings, which I review here.

Older posts about Marie Tharp can be found here.

Update, July 30: Suzanne O’Connell at The Conversation: “As a geoscientist, I believe Tharp should be as famous as Jane Goodall or Neil Armstrong. Here’s why.”

The bare bones of Tharp’s story are therefore fairly well known: while mapping the floor of the Atlantic Ocean, she discovered the presence of the Mid-Atlantic Ridge—and, more specifically, its rift valley, providing tangible evidence of continental drift. Because continental drift was at that point considered to be a crackpot theory, it took some doing for Tharp’s discovery to be accepted; and when it was her contributions were to some extent minimized.

While Felt’s book is positioned as a biography, its strength is in the details of that pivotal discovery: how and where it was made, and by whom, and in what context. Tharp’s work was not done in a vacuum, and how and why she was where she was is important. Felt sets the stage for us: not only does she take us through Tharp’s early childhood and rather variegated education and her arrival in 1948 at the Lamont Observatory, she gives us a short history of that Observatory, of the theory of continental drift, of her colleagues—notably her lifelong collaborator (and possibly life partner) Bruce Heezen and Observatory director (and sometime antagonist) Maurice Ewing. More than anything else, Soundings provides context for Tharp’s discovery: by the time we’re done, we know how important it was, and why. We’ve been well briefed.

Felt is less successful in building a portrait of Tharp herself. Some areas of her non-work life—her childhood, family and college education, for example—are extremely well covered, but other areas have considerable gaps, particularly those involving her personal life. The nature of Tharp’s relationship with Heezen is only hinted at, as is an early, unsuccessful marriage to someone else. Her later life, supported by a motley gang of eccentrics called Tharpophiles, is also incompletely covered. The elisions, however unintended, are frustrating. I suspect the author was a prisoner of her source material, which in places she follows very closely; I would have liked it if more had been done to fill in the gaps.

Soundings was published in hardcover by Henry Holt in 2012. It’s available in paperback and ebook from Picador.

Amazon | iBooks

On the WMS Facebook group, Bert Johnson had this to say about this latest profile: “Hers is a standout story, but I wish some of these journalists who keep running these would spend some time and effort discussing some of the other women—known and unknown—who made contributions and helped open the doors of cartography to women.”

Marie Tharp, who died in 2006, has never been more in the public eye. This short film for the Royal Institution, animated by Rosanna Wan and narrated by Helen Czerski, is the fourth profile I’ve seen of her within the past year. [National Geographic]