![\"Geologic](\"https:\/\/explore.globalcreations.com\/theblog\/wp-content\/uploads\/2015\/08\/GeologicMap550.jpg\")
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To do their thing, explorers first learn everything they can from those that have come before. \u00a0Several years ago the U.S. Geological Survey (USGS) delivered some\u00a0results\u00a0from their explorations that gave\u00a0us more to know about Crater Lake, located in Crater Lake National Park, Oregon, the deepest lake in the United States. \u00a0A lake once believed to be bottomless.<\/p>\n
They mapped the bottom of the lake using a high-resolution multi beam echo\u00a0sounder. A map of a lake or ocean bottom is called a bathymetric map and the survey work used to produce the map is called a bathymetric survey. \u00a0This bathymetric survey provides a 2\u00a0meter per\u00a0pixel view of the lake floor from\u00a0its deepest basins to the shoreline.<\/p>\n
Using the survey data and information about the geology of the area, researchers created the above bathymetric map. \u00a0On it we can see some interesting things.<\/p>\n
First<\/strong>, we’ve always known that the rocks making up the Phantom Ship<\/a> are some of the oldest in the lake area. \u00a0Here we can see that rocks of a similar age are scattered around the lake near the shoreline. \u00a0These are the rocks shown in a dark yellow and labeled “maz.” \u00a0These rocks were part of Mt. Mazama before it blew.<\/p>\n Second<\/strong>, and not surprisingly, even older rocks are found beneath the “maz” rocks. \u00a0These are shown in a pale blue and labeled “pmu.” \u00a0The rocks were there before Mt. Manama formed on top of them.<\/p>\n Third<\/strong>, besides the small parts of the lake bed made of the above rocks, there are really only two types of geologic material\u00a0on the lake bed: rocks and other materials that found their way into the lake as the sides of the caldera slid and eroded into it (white and lighter shades of yellow) and newer rocks created\u00a0from\u00a0volcanic activity that occurred in the caldera after the mountain blew its top (greens and reds).<\/p>\n Fourth<\/strong>, we can see the terrain of the lake bottom. \u00a0Thanks to the way the data was collected, it can be manipulated using geographic information systems to give us an infinite variety of views. \u00a0The view shown below is as if you were standing\u00a0at the visitors overlook at The Watchman. \u00a0Click the image to see a larger version.<\/p>\n <\/p>\n
![\"Perspective](\"https:\/\/explore.globalcreations.com\/theblog\/wp-content\/uploads\/2015\/08\/PerspectiveView550.jpg\")
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