http://gallery.usgs.gov/images/logos/usgs_only.jpg http://gallery.usgs.gov/ en-us OC_Web@usgs.gov (Office of Communications Web Group) http://gallery.usgs.gov/images/USGS.gif http://gallery.usgs.gov/ http://gallery.usgs.gov/photos/03_11_2013_hmd5Gsr11A_03_11_2013_0 Kīlauea Volcano's summit vent within Halema‘uma‘u Crater was about 115 feet in diameter in April 2008, a month after it opened. 

]]> http://gallery.usgs.gov/photos/03_11_2013_hmd5Gsr11A_03_11_2013_1 Kīlauea Volcano's summit vent within Halema‘uma‘u Crater was more than 500 feet across in March 2013, five years after it opened.

]]> http://gallery.usgs.gov/photos/03_11_2013_hmd5Gsr11A_03_11_2013_2 Kīlauea Volcano's summit vent "then and now."  In April 2008 (top image), a month after it opened, the vent within Halema‘uma‘u Crater was about 115 feet in diameter.  As of March 2013 (bottom image), it is more than 500 feet across.  

]]> http://gallery.usgs.gov/photos/03_04_2013_rvm8PCb55J_03_04_2013_0 3-Dimensional view of Decorah, Iowa and the Upper Iowa River. Scene is looking due north. 

]]> http://gallery.usgs.gov/photos/02_28_2013_txo0REd55L_02_28_2013_0 Views, looking west, to downtown Decorah, Iowa, from a city park bluff on east side of town.  Downtown courthouse tower and church spires are prominent.  

]]> http://gallery.usgs.gov/photos/02_28_2013_txo0REd55L_02_28_2013_1 Views, looking west, to downtown Decorah, Iowa, from a city park bluff on east side of town.  Downtown courthouse tower and church spires are prominent.  

 

]]> http://gallery.usgs.gov/photos/02_28_2013_txo0REd55L_02_28_2013_2 Views, looking west, to downtown Decorah, Iowa, from a city park bluff on east side of town.  Downtown courthouse tower and church spires are prominent.  

 

]]> http://gallery.usgs.gov/photos/02_28_2013_txo0REd55L_02_28_2013_4 Shows electro-magnetic, well data and aggregate results.

]]> http://gallery.usgs.gov/photos/10_14_2011_i4Dpg66ff0_10_14_2011_0 Photo of fossil algae (dinocyst). Specimen is about 90 micrometers across.The largest known impact crater in the U.S. lies buried beneath the Virginia Coastal Plain. The late Eocene Chesapeake Bay impact event caused a wide variety of distinctive features, such as fossil algae (dinocysts) that were found in drilled cores from hundreds to thousands of feet below the surface. The study of distinctive preservational features, whether related to the crater or not, leads to more questions than answers. How was a specific feature formed? How did it come to be preserved in the fossil record?

]]> http://gallery.usgs.gov/photos/10_14_2011_d2Xk05Nba7_10_14_2011_6 A geologist finishes field notes after mapping the extent of Crater Glacier at Mount St. Helens. Crater Glacier, formed by the accumulation of snow and rocks falling from the inside of the crater rim and walls, began to deform and flow in 1996. Over the past five years, Crater Glacier's terminus has been advancing at about 30 cm per day. Mapping the glacier's extent and volume are important for assessing lahar hazards. Should the glacial ice and snow be melted swiftly by a future dome-building eruption, a torrent of glacial meltwater could produce a fast-moving flood of water and debris that pours onto the Pumice Plain and possibly down the North Fork Toutle River.

]]> http://gallery.usgs.gov/photos/09_21_2011_pTKw40Ymm2_09_21_2011_0 The USGS Hawaiian Volcano Observatory is perched on the rim of Kilauea Volcano's summit caldera (next to the Thomas A. Jaggar Museum in Hawai`i Volcanoes National Park), providing a spectacular view of the active vent in Halema‘uma‘u Crater.

]]> http://gallery.usgs.gov/photos/07_06_2011_mQHt3WVjj1_07_06_2011_0 A channelized flow was being erupted today from the vent on the west side of the floor of Pu'u 'O 'o.

]]> http://gallery.usgs.gov/photos/07_06_2011_mQHt3WVjj1_07_06_2011_1 Following several collapses and small explosive events that deposited spatter on the floor of Halema'uma'u crater around noon, the lava surface in Halema'uma'u was roiling and agitated for the remainder of the afternoon, with numerous points of upwelling and spattering.

]]> http://gallery.usgs.gov/photos/07_06_2011_mQHt3WVjj1_07_06_2011_2 A close-up of the active lava surface in Halema'uma'u.

]]> http://gallery.usgs.gov/photos/07_06_2011_mQHt3WVjj1_07_06_2011_3 Another large chunk of the rim collapsed into the Halema'uma'u lava lake.

]]> http://gallery.usgs.gov/photos/07_06_2011_mQHt3WVjj1_07_06_2011_4 Just moments after the last photograph, the collapse produced a thick brown plume, but did not appear to trigger an explosive event in this case.

]]> http://gallery.usgs.gov/photos/07_06_2011_w0Rev22ut5_07_06_2011_0 Ash cloud rising from Pu'u 'O 'o as crater floor collapses due to magma withdrawal. Incandescent rubble can be seen crumbling and rolling down the scarp. The east rim of Pu'u 'O 'o is in the foreground.

]]> http://gallery.usgs.gov/photos/07_06_2011_w0Rev22ut5_07_06_2011_1 Incandescent rubble rolling and sliding down the scarp on the edge of the collapsing crater in Pu'u 'O 'o. A remnant of the pre-collapse crater floor can be seen in the background below the crater's south wall. The east rim of Pu'u 'O 'o is in the foreground.

]]> http://gallery.usgs.gov/photos/07_06_2011_w0Rev22ut5_07_06_2011_2 New fissure eruption SW of Pu'u 'O 'o between Pu'u 'O 'o and Napau crater. Spatter is reaching 15-20m into the air, above the trees. Pu'u 'O 'o in the background.

]]> http://gallery.usgs.gov/photos/07_06_2011_w0Rev22ut5_07_06_2011_3 New fissure eruption SW of Pu'u 'O 'o between Pu'u 'O 'o and Napau crater. Spatter is reaching 15-20m into the air, above the trees.

]]> http://gallery.usgs.gov/photos/07_06_2011_w0Rev22ut5_07_06_2011_4 View to the SW at the new fissure eruption between Pu'u 'O 'o and Napau. Cracks in the foreground could be seen opening as photo was being taken.

]]> http://gallery.usgs.gov/photos/07_06_2011_w0Rev22ut5_07_06_2011_5 Close-up of recently opened fissure segment. Spatter reaching about 5m into the air.

]]> http://gallery.usgs.gov/photos/07_06_2011_ua5Ctg2SRn_07_06_2011_0 Early morning view of the fissure eruption between Napau Crater and Pu'u 'O 'o. View is to the northwest. Fume from the eruptive vent in Halema'uma'u can be seen at upper right against the dark mass of Mauna Loa.

]]> http://gallery.usgs.gov/photos/07_06_2011_ua5Ctg2SRn_07_06_2011_6 This fissure is erupting 1.5 km (0.9 mi) west of Pu'u 'O 'o Crater. You can view this eruption on the new Pu'u 'O 'o to Napau Crater webcam.

]]> http://gallery.usgs.gov/photos/07_06_2011_ua5Ctg2SRn_07_06_2011_11 Increased activity on one of the new fissures between Pu'u 'O 'o Crater and Napau.

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