The Lecture: Mapping the Glacial Legacy of the Pacific Northwest
Glaciers have shaped much of the Pacific Northwest’s landscape over the past 15,000 years. The Cordilleran ice sheet, repeated ice age floods, and expansive alpine glaciation have left their distinctive fingerprints on the topography of our region. Geologists and cartographers have been mapping and interpreting glacial landforms since the late 19th century. In the past decade, the Washington Geological Survey has created new maps that build upon this rich cartographic history by fusing older datasets and techniques with modern insights and technology, such as lidar.
Using both historical and modern maps, this presentation will be a visual journey through the Pacific Northwest’s glacial past and present.
This IN-PERSON ONLY lecture will start at 4 PM on Saturday, March 8, 2025 at Port Townsend First Baptist Church (located at 1202 Lawrence St, Port Townsend, Washington). This is free and open to the public. (Donations gratefully welcome at the door.) This lecture will be recorded and posted shortly after the presentation, as are all our events since 2020.
About the Speaker:
Daniel Coe has been making maps of the Pacific Northwest for the past two decades. He currently serves as graphics editor for the Washington Geological Survey in Olympia, Washington, and was an editor for the North American Cartographic Information Society’s recently released Atlas of Design, volume 7. Daniel’s award-winning cartographic work explores the geomorphology and natural hazards of the Pacific Northwest and beyond. When not making maps, he is usually out enjoying the forests and waters of Washington with his family. You can see Daniel’s work at dancoecarto.com.
Earth’s mantle and then are brought rapidly to the surface in CO2-rich explosive eruptions. No such eruptions have occurred in human history, but we know they occur only in the interiors of continents, where they produce narrow vertical ‘kimberlite pipes’ that are mined in Africa, Russia, and, more recently, Canada. Tiny diamonds with a completely different origin have been found in meteorites, and some of these appear to predate the formation of our solar system. Nowadays, diamonds can also be grown artificially, and these synthetic crystals are widely used in industry and, increasingly, in jewelry. For geologists, diamonds are invaluable tools for understanding the Earth’s interior. 
They are used to make tiny “anvils” that allow us to conduct high-pressure laboratory experiments that replicate conditions deep inside the Earth, and they commonly contain minute inclusions of other minerals that are our only actual samples of mantle materials from depths as great as ~400 km (250 miles). Jeff provided how and where diamonds form, offered a brief summary of how we search for them, described their history as gemstones, and detailed what they tell us about our planet’s deep interior.