Covering a brief history of Glacial Lake Missoula and the factors leading to its creation and dam-bursting flood, GigaFlood follows the path of the largest of the Lake Missoula Floods, as its 540 cubic miles of water, 40 cubic miles of ice, 50 cubic miles of rock, sediment and debris tore down the Columbia River Gorge at speeds up to 65 miles per hour, and traces the influx and exit channels in the areas north and south of the Columbia River as it overflowed the Portland/Vancouver area as well as the Clackamas, Tualatin Yamhill and Willamette valleys up to the 400 foot level.
With 208 pages, 182 photographs, 52 maps, and 10 illustrations, GigaFlood reveals the many indelible marks left on the landscape such as kolk lakes, gravel bars 200-300 feet high, truncated hillsides, flood channels, and erratics boulders. Many of these subtle features were previously unrecognized though hidden in plain sight.
Like a detective story GigaFlood points out the clues in NW Oregon and SW Washington that show the effects of this cataclysm and reveals what those features are and how they were formed. You will see this area with new eyes and it will never be the same again.
Industry Reviews
The great Glacial Lake Missoula floods washed down the Columbia River during the period between about 15,000 and 13,000 years ago, perhaps as many as several dozen times. Their passages did enormous mischief in the Portland Area, leaving it strewn with areas of wildly eroded land and bizarre deposits of sediment. Those strange features told in detail the story of the floods. Now, after a century of urban development, much of that evidence has been bulldozed, paved, and covered with buildings.
Rick Thompson has found much of the surviving evidence and assembled it into this good and urgently needed book. It will show its readers what is underfoot in the Portland area, enrich the experience of living in Portland. This is a good book.
- Dave Alt, Ph. D Professor emeritus of geology University of Montana
GIGAFLOOD is one of the best books that I have read regarding the event of the first of many Missoula (Bretz) floods. Although I have a library full of books on geology describing the floods, most of them are very technical and the average person would have trouble understanding all the fine details especially their geologic terminology used by the scholars who have written those books. GIGAFLOOD, even though it is technical in nature and covers a subject that can be studied for years, it is also for the average person who is curious to know some of the broad details of this amazing cataclysm (the first of many floods), but may not have the time nor the expertise to get into specific details. The book is full of anecdotes and personal observations ranging from where the flood began through the Willamette Valley nearly 1000 miles away.
GIGAFLOOD not only covers and explains what happened during that incredible event, but the colorful text and explanations makes the flood very real by showing the geologic results we see today. He also includes excellent pictures and maps with directions to help the reader find and understand the various geologic features caused by the flood. Following his superb directions is like having a private guide for the entire family. If it were not for this book the average person would probably never know how and why the natural features around them were formed. I highly recommend this book to both casual readers and experts in the field. It is a must have book especially for anyone traveling through the territories affected by the flood especially the Columbia River Gorge.
- Ken Manske
