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USGS News: Everything We've Got
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This is every single news item we post. If you want it all, here it is.
This is every single news item we post. If you want it all, here it is.

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Polar Bears Film Their Own Sea Ice World: This clip garnered the most views ever for the USGS on YouTube, just over 400,000, and still growing. A just-published study in Science used videos recorded in 2014-2016 to shed more light on how much food polar bears need to survive. Download this videoThis video showcases the latest polar bear point-of-view footage to date along with an interview of the research scientist who is responsible for the project. Released in conjunction with a new scientific study led by the USGS. (Credit: USGS. Public domain.) Although being able to glimpse these remarkable animals as they navigate their sea ice world was fascinating, the videos had a specific research function: USGS researchers, led by Anthony Pagano, were trying to learn about the behaviors and foraging rates of polar bears on the sea ice so ultimately, they could better understand how much food the bears need to be healthy and survive. Up until 2014, most of our understanding of polar bear behavior as they roamed the sea ice were from direct observations made by Dr. Ian Stirling more than 40 years ago and from observations made by coastal indigenous residents. By equipping the GPS collars with a video camera, the research team were able to link high resolution location data with the actual behavior and foraging success recorded by the camera. This combination enabled scientists to begin to understand the activity patterns of polar bears, for example how often they hunt, eat, rest, walk, and swim and how these behaviors may be affected by sea ice conditions and other variables. New batches of POV video and GPS location data collected in 2015 and 2016 contributed to Pagano’s research. An adult female polar bear on the sea ice wearing a GPS satellite video-camera collar. GPS video-camera collars were applied to solitary adult female polar bears for 8 - 12 days in April, 2014-2016. These collars enabled researchers to understand the movements, behaviors, and foraging success of polar bears on the sea ice.(Credit: Anthony M. Pagano, USGS. Public domain.) The data collected during those years allowed Pagano and his team of scientists to examine the energetic rates and nutritional demands of these animals. In this study, researchers developed a way to measure a polar bear’s metabolic rate, or, said more simply, they discovered how many seals a polar bear needs to eat in order to survive. Their research also suggests that increases in movement rates resulting from reductions in sea ice could greatly increase the energy demands of these animals. This idea is based on inferences drawn between Pagano’s research and previous independent research on habitat loss and polar bear movements to suggest that it is becoming more challenging for polar bears to capture prey because the sea ice platform they use to forage off is available for a shorter time during the year. An adult male polar bear still-hunting at a seal hole on the sea ice of the southern Beaufort Sea.(Credit: Mike Lockhart, USGS. Public domain.) Despite being sit-and-wait predators, the videos and data showed that the measures of activity were in line with other terrestrial carnivores. The study also revealed that the day-to-day activities of polar bears are 60 percent more energetically costly than previously assumed. The new paper, “High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear,” appears in the journal Science. It is authored by Pagano, along with his USGS co-authors George Durner, Karyn Rode, Todd Atwood, and Elizabeth Peacock; University of California, Santa Cruz researchers Terrie Williams and Daniel Costa; Stephen Atkinson of Dugald, Manitoba; and Megan Owen at the San Diego Zoo Institute for Conservation Research. Special thanks to Mehdi Bakhtiari for developing the collars used in this study. This work was supported by the U.S. Geological Survey’s Changing Arctic Ecosystems Initiative. Additional support was provided by Polar Bears International; World Wildlife Fund (Canada); San Diego Zoo Global; University of California, Santa Cruz; and the International Association for Bear Research and Management. #usgs #news

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U.S. Mines Produced an Estimated $75.2 Billion in Minerals During 2017: The report from the USGS National Minerals Information Center is the earliest comprehensive source of 2017 mineral production data for the world. It includes statistics on more than 90 mineral commodities that are important to the U.S. economy and national security. It also identifies events, trends and issues in the domestic and international minerals industries. This report covers the full range of nonfuel minerals monitored by the center, not just critical minerals, which were described in the recent USGS Critical Mineral Resources publication; which was released in December of 2017. “The Mineral Commodity Summaries provide crucial, unbiased statistics that decision-makers and policy-makers in both the private and public sectors rely on to make business decisions and national policy,” said Steven M. Fortier, the center’s director. “Industries – such as steel, aerospace, and electronics – processed nonfuel mineral materials and created an estimated $2.9 trillion in value-added products in 2017 or 15 percent of the total U.S. Gross Domestic Product.” This map shows the countries that supply mineral commodities for which the United States was more than 50 percent import reliant in 2017. (Map: USGS. Public domain.) According to this year’s report, the United States continues to rely on foreign sources for some raw and processed mineral materials. In 2017, the country was 100 percent import-reliant on 21 mineral commodities including rare earths, manganese, niobium and vanadium. This number of 100 percent import-reliant minerals has increased from just 11 commodities in 1984. The $75.2 billion in nonfuel mineral production by U.S. mines this year is made up of industrial minerals, including aggregates, and metals. Thirteen mineral commodities produced in the United States were worth more than $1 billion each in 2017. The estimated value of U.S. industrial minerals production in 2017 was $48.9 billion, 3 percent more than that of 2016. Increased natural gas and oil production benefitted some of the industrial mineral sectors. However, slower construction activity resulted in stagnant production in industrial minerals used in construction.  U.S. metal mine production in 2017 was estimated at $26.3 billion and was 12 percent more than that of 2016. Supply concerns and increased investor activity resulted in higher prices in 2017 for most metals. However, despite higher metal prices, domestic production was lower than the previous year.   In 2017, 11 states each produced more than $2 billion worth of nonfuel mineral commodities. These states were, in descending order of value: Nevada, Arizona, Texas, Alaska, California, Minnesota, Florida, Utah, Missouri, Michigan and Wyoming. Some other significant findings in the new report on domestic production include: Construction Sand and Gravel, Crushed Stone, and Dimension Stone: Construction-related industrial minerals remained essentially unchanged or saw slight decreases in production and demand in 2017. Much of this decline was due to weather events along the Gulf Coast and in the Southeast, mixed-to-slight growth in expenditures in residential and nonresidential sectors, and a slight decline in expenditures for public sector construction. Aluminum: U.S. production of primary aluminum decreased for the fifth consecutive year, declining by about 12 percent in 2017 to the lowest level since 1951. U.S. imports of aluminum increased by 16 percent in 2017.  Rare Earths: The suspension of U.S. rare-earth mining in late 2015 continued throughout 2017. In Nebraska, one company commissioned an operation that produced separated rare earth oxides from recycled fluorescent light bulbs. The company planned to ramp up production to 18 tons per month using a proprietary technology. Gold: Two new gold mines opened in late 2016 and 2017; one in Nevada and one in South Carolina – this was the first gold mine east of the Mississippi River since 1999. Cobalt: Average annual cobalt prices more than doubled, owing to strong demand from consumers, limited availability of cobalt on the spot market, and an increase in metal purchases by investors. Lithium: Strong demand from consumers drove the average price of lithium up 61 percent in 2017 vs. 2016.  The USGS Mineral Resources Program delivers unbiased science and information to understand mineral resource potential, production, consumption and how minerals interact with the environment. The USGS National Minerals Information Center collects, analyzes and disseminates current information on the supply of and the demand for minerals and materials in the United States and about 180 other countries. This information is essential in planning for and mitigating impacts of potential disruptions to mineral commodity supply due to both natural hazard and man-made events. The USGS report Mineral Commodity Summaries 2018 is available online. Hardcopies will be available later in the year from the Government Printing Office, Superintendent of Documents. For ordering information, please call (202) 512-1800 or (866) 512-1800 or go online.  For more information on this report and individual mineral commodities, please visit the USGS National Minerals Information Center. To keep up-to-date on USGS mineral research, follow us on Twitter or visit the Mineral Resources Program webpage. #usgs #news

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January 23, 2018 M7.9 Gulf of Alaska Earthquake and Tsunami:   Four minutes later, Alaskans in coastal communities were awakened with blaring alarms when NOAA’s National Tsunami Warning Center sent out a Tsunami Warning for the state and the west coast of Canada based on the quake’s magnitude and its proximity to the coast. At the same time, a Tsunami Watch was issued for California, Oregon, and Washington. Ultimately, a small tsunami surge, less than one foot deep, was observed in Kodiak and smaller water-level increases occurred in other Alaskan coastal communities. A water-level rise of a few inches was detected four and a half hours later in Arena Cove, California. Three hours after the initial tsunami advisory was issued, NOAA canceled it. Point Arena tide gauge at Arena Cove recorded a small tsunami several hours after the earthquake in Alaska. Additional small fluctuations in the water level continued to occur.(Public domain.)   Historical Large Alaskan Quakes The first thing many people think of when they learn there has been a significant earthquake in Alaska are the infamous 20th century quakes that occurred in the Alaska-Aleutian Subduction Zone, such as the magnitude 9.2 Great Alaska Earthquake and Tsunami of 1964. Subduction zone quakes have the potential to generate very strong ground shaking, and accompanying dangerous tsunamis as occurred in 1964. After U.S. Geological Survey scientists analyzed the data recorded on the network of seismographs, they quickly realized, with some relief, that the Jan 23 event happened on a strike-slip fault, and not in the subduction zone. The 1964 Great Alaska Earthquake generated not only a very large tsunami that traveled across the Pacific Ocean, but the strong shaking also triggered undersea landslides, resulting in deadly local tsunamis that wiped out entire coastal villages. Location of the January 23, 2018 earthquake (red star) relative to the 1938, 1946, and 1964 earthquake rupture locations (pink-shaded areas).(Public domain.) Location of Jan 23, 2018 eartthquake epicenter (orange star) and locations of historical quakes (white dots) in the area since 1900.(Public domain.)   The January 23 Tsunami Earthquakes in the past that have generated large tsunamis — such as the 1964 Great Alaska Earthquake and Tsunami, the 2011 M 9.1 Tohoku earthquake, and the 2004 M 9.1 Sumatra earthquake — caused significant vertical deformation of the seafloor, and thus a large amount of displaced water. The January 23 Alaska quake, however, was the result of strike-slip faulting within the shallow lithosphere of the Pacific Plate (commonly known as the Earth’s crust). Because the January 23rd quake was generated by a strike-slip motion, only a small tsunami was generated, and the risk of a more significant tsunami was low. Strike-slip earthquakes involve horizontal motion across a fault, and do not generate significant uplift or subsidence. This means they do not, in turn, cause the significant displacement of the water column above the earthquake rupture required to generate a large tsunami.   Block diagram of a Strike-Slip fault.(Public domain.) Block diagram of a subduction zone when two oceanic plates converge.(Public domain.) Although strike-slip faults are less likely to cause vertical deformation of the seafloor and displace large amounts of water to generate a large tsunami, they can still be very dangerous. Any strong earthquake shaking could potentially dislodge submarine landslides and trigger a deadly local tsunami. Consequently, it was very important that the people in Kodiak, Homer spit, and parts of Seward evacuated when they received the tsunami warning, and that the police advised them to stay in place until the tsunami warning was cancelled.   What Did People Feel? A few people on Kodiak Island felt moderate to strong shaking, but most Alaskans felt only weak to light shaking; because this earthquake occurred almost over 225 miles offshore from mainland Alaska, its impact was minimized. Shaking intensity: The lavender colors on the map represent weak shaking, and the blue to turquoise colors represent light shaking. Areas nearer the coast (and closer to the epicenter) experienced slightly stronger shaking than areas farther away.(Public domain.) For the Jan. 23 earthquake, the USGS “Prompt Assessment of Global Earthquakes for Response” (PAGER), alert level was “green,” indicating low probabilities of fatalities and low probabilities of significant economic losses. PAGER combines measurements of shaking with demographic and infrastructure information to estimate damage and loss of life probabilities. USGS PAGER assessment summary for January 23 Alaska earthquake.(Public domain.) Tectonic Setting Near the location of the January 23 earthquake, the Pacific (tectonic) Plate is moving to the north-northwest, toward the North American Plate at a rate of approximately 59 mm/year (a little over 2 inches per year). The Pacific Plate subducts, or sinks, beneath the North American Plate at a deep-sea trench that defines the Alaska-Aleutian subduction zone on the seafloor, about 90 km (56 miles) to the northwest of the Jan. 23 earthquake epicenter. The location and mechanism of the January 23rd earthquake show it occurred on a fault system within the Pacific Plate, about 16 miles deep, rather than on the actual plate boundary between the Pacific and North American Plates further to the northwest.   Far-Away Effects of Large Earthquakes In addition to the well-known ground shaking, tsunamis, and other hazards, large earthquakes can produce effects very far away from their source location. Large quakes can cause well-water levels in areas far away from the quake to either drop or rise, depending on the local geology near the well, but not all wells show this effect. Scientists are tracking these water-well changes so they can learn more about the Earth’s structure near a well, and the geophysical properties of how earthquake energy travels through the Earth’s crust. More than 3,500 miles from the Gulf of Alaska Earthquake’s epicenter, water levels at a USGS groundwater well near Madison, Florida spiked by about two inches, while levels at the USGS groundwater well near Fort Lauderdale, Florida, dropped by an inch and a half. Both recovered to their previous levels within an hour. January 23rd was not the first time a major Alaska earthquake caused groundwater effects far from its epicenter. Water-level fluctuations caused by the magnitude 9.2 1964 Great Alaska Earthquake were recorded in 716 wells in the United States; the earthquake also was registered on water-level recorders in many other countries. The 2004 northern Sumatra Earthquake, and even the smaller 2011 Mineral, Virginia earthquake also affected groundwater level in wells far away. Hydrogeologic responses to earthquakes have been known for decades, and have occurred both close to, and thousands of miles away from earthquake epicenters. Water wells have become turbid, dry or begun flowing, discharge of springs and ground water to streams have increased and new springs have formed, and well and surface-water quality have become degraded as a result of earthquakes. Hydrographs from two USGS groundwater monitoring sites in Florida show groundwater levels affected by the seismic waves from the M7.9 earthquake near Kodiak, Alaska. (Public domain.)   Examples of hydrographs indicating possible groundwater level changes due to January 23, 2018, Gulf of Alaska M7.9 earthquake. (These data are preliminary or provisional and are subject to revision.) These provisional data are presented in a combined, simplified figure to highlight the observed change in water levels associated with the earthquake. Note that water levels have not been corrected for barometric pressure and Earth tide affects(Public domain.)   Aftershocks There will likely be vigorous aftershocks in the magnitude 4-5 range over the weeks and months following the January 23, 2018 earthquake, with aftershocks in the M6 range also possible, but less frequent. There is a small, but non-zero chance of the M 7.9 January 23, 2018 earthquake triggering a nearby event of comparable size or larger.   60 aftershocks greater than or equal to M4.0 occurred in the first 48 hours after the mainshock. The blue dot is the location of the main Jan 23 earthquake. Yellow and orange dots are aftershock epicenters.(Public domain.) #usgs #news

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Salinity Decreased throughout Upper Colorado River Basin Over Time: The study also shows the majority of salinity in the Upper Colorado River Basin comes from groundwater that discharges into streams, also known as baseflow. This occurs as snowmelt and precipitation infiltrate into the ground and interact with sedimentary rocks, which causes salts to dissolve and salinity to increase in groundwater. Salinity has a significant impact on water users in the Colorado River Basin, affecting agricultural, municipal and industrial sectors, and causing almost $300 million per year in economic damages in the United States. Findings show that as much as 89 percent of salinity in the upper Colorado River comes from baseflow. The study estimated salinity loads in baseflow at 69 stream sites throughout the basin to better understand where salinity originates and how it is transported through the watershed. The study also examined salinity trends in baseflow from 1986-2011 to learn how conditions have changed over time. USGS scientists developed models and incorporated long-term data from sites throughout the Upper Colorado River Basin to provide estimates of how much salinity moves from groundwater to streams. “Understanding how salinity moves through the Colorado River basin is critical for resource managers in helping them develop effective mitigation strategies,” said Christine Rumsey, a USGS scientist and the lead author of the study. Declines in baseflow salinity loads occurred in 63 percent of streams studied between 1986-2011. This decline suggests that salinity mitigation projects may be reducing loads. Other possible causes for the decreased salinity transport include climate and landscape changes. Notably, the pace and extent of decreases in baseflow salinity declined during the 2000s. The average rate of decreases during the 2000s was only half of the average rate of decreases in the 1990s. “While this is a great first step toward understanding how salinity has changed over time, more studies are needed to better understand why salinity loads are declining in the basin, and why, at many sites, the rate of decline was weaker in more recent years,” said Rumsey. Salinity occurs naturally in water due to the weathering and dissolution of minerals in soil and rock. The same process occurs in areas with irrigated agriculture, which produces about double the salinity yield compared to areas without irrigated agriculture. Other factors known to affect salinity loads in streams include geology, land cover, land-use practices and precipitation. Funding for this study was provided by the Bureau of Reclamation Colorado River Basin Salinity Control Program. In 1974, Congress enacted the Colorado River Basin Salinity Control Act, which directed the Secretary of the Interior to proceed with a program to enhance and protect the quality of water available in the Colorado River for use in the U. S. and Republic of Mexico. The Colorado River Basin Salinity Control Program implements and manages projects to reduce salinity loads, investing millions of dollars per year in irrigation upgrades, canal projects and other mitigation strategies. The new study was published in the journal Hydrologic Processes. Muddy Creek in the San Rafael Swell with white surface salts. Public domain.  Dry wash in San Rafael Desert with white surface salts. White efflorescent salts form on the soil surface as water evaporates from the soil leaving the salt at the surface. Public domain. #usgs #news

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USGS Geologists Join Efforts in Montecito to Assess Debris-Flow Aftermath: Days after fatal debris flows devastated Southern California’s Montecito community,  a team of U.S. Geological Survey geologists joined county, state, and federal partners to survey and  evaluate the aftermath. Commonly known as mudslides or mudflows,  debris flows are slurries  of water, rock, soil, vegetation, and boulders with the consistency of wet concrete that can move rapidly  downhill and down channel. USGS geologists from the Landslide Hazards Program and Earthquake Science Center  deployed to Santa Barbara County to support a geohazard assessment of the Montecito area; lead by the California Geological Survey,  with the support of the California Department of Forestry and Fire Protection (CAL FIRE). “We’re  mapping the area that’s been inundated by debris flows so that we are able to get some sense of the spatial extent of the area  debris flows impacted,  as well as the magnitude of the flows,”  said USGS geologist Dennis Staley. “We will also be able to produce a forensic reconstruction of what happened throughout the event.” Download this videoA team of USGS geologists provide science support following Montecito post-fire debris-flow event. Donyelle K. Davis,(Public domain) Based on the information the group collects from the area, they can estimate  the velocity and other dynamics of the flow to better understand  and forecast how similar events might behave in the future. Real-time Techniques Help to Monitor Hazards The Dec. 4, 2017 Thomas fire, Southern California's largest wildfire on record, burned more than 280,000 acres across Ventura and Santa Barbara counties for nearly a month.  After the wildfire, the USGS completed a Post-Fire Debris-Flow hazard assessment to determine debris-flow susceptibility. The hazard assessment uses information on burn severity, topography, and soil characteristics to estimate the likelihood and volume of debris flows in response to a design storm.  The maps need to be created rapidly after the fire, but before the first storm,  in order to provide as much time as possible to develop emergency response plans. The maps are also used by the National Weather Service offices in southern California to inform debris-flow and flash-flood alerts. “In this case, the maps showed that many drainages across the fire are highly susceptible to debris flows even during a garden-variety storm,” said USGS hydrologist Jason Kean. “The burst of rain that triggered the debris flows was more than  three times greater than the design storm that was used to create the maps.” According to the maps, the Montecito area, as well as other parts of the Thomas Fire, may remain susceptible to flooding and debris for the next two years. Weeks after the fire, which destroyed thousands of structures,  heavy rainfall eroded the burned areas  — saturating the Montecito community with between 3-5 inches of rain. fullscreen Status: PublishedScience Support: Communications and Publishing Areas of steep topography subjected to intense rainfall, following a large fire, are particularly susceptible to damaging  debris-flow episodes.   Debris flows can start on steep hillsides as shallow landslides that liquefy and accelerate to speeds that are typically about 10 mph, but can exceed 35 mph. However, in recently burned areas, debris flows may also initiate from erosion on hillsides and from stream channels. The flows then reach canyon mouths or flatter ground, where the material spreads over a broad area, sometimes accumulating in thick deposits that can wreak havoc in developed areas. “Post-fire debris flows are particularly hazardous because they can occur following very short bursts of intense rainfall,” said Jonathan Godt, USGS Landslide Hazards Program Coordinator. “Because debris flows move fast with great momentum they, can strip vegetation, block drainage ways, damage structures, and endanger human life.”   Boots-on-Ground Evaluations Among the remains of demolished infrastructure, the team of scientists trudged through miles of  thick, deep mud, rubble and wreckage to map the edges of the flow. They recorded flow features such as deposit thickness, size of boulders and inundation depth on GPS-connected electronic tablets.  The location data are used to help emergency responders and will be used to model the flow.    After a debris flow event, satellite imagery helps document the scope of the event, but in order to provide the best data to emergency responders and to learn from this event, scientists must physically canvass the scene.   fullscreen Status: PublishedScience Support: Communications and Publishing “It’s important for scientists  to  be in the field shortly following the debris flow to collect perishable measurements of the depth, character and perimeter of the debris flows,” said research geologist Dr. Kate Scharer. “By working on the ground, we can evaluate the features that influence how the debris flow spreads across the land and then use these data in models to inform federal, state and local partners how future events can unfold.”     For this project, the scientists were also focused on understanding how the terrain controlled the path of the debris flows, and how the area inundated by the debris flow deposits was different or similar  than what was estimated using flood models.   Partner Collaborations Advance Hazard Understanding Understanding and mapping post-fire debris flow inundation serves multiple objectives for all organizations involved. The partnership between Santa Barbara County, CAL FIRE’s Watershed Protection Program,  the disaster incident command, CGS and USGS, will meet immediate and long-term needs. fullscreen Status: PublishedScience Support: Communications and Publishing After the team identifies areas that were inundated by the January 9, 2018 event, as well as areas that could be inundated in future, the data collected now will be used in a long-term effort to develop models of debris-flow runout and inundation. “This effort assists Santa Barbara County and the State of California with additional tools to map post-wildfire landslide hazards in areas at risk,” said Jeremy Lancaster, CGS Regional Geologic Mapping Program Manager. “The results of this information can also be used in post-wildfire hazards evaluations and risk reduction efforts in California, and may be broadly applicable to large regions of the United States.”   USGS geologists from the Landslide Hazards Program and Earthquake Science Center  deployed to Santa Barbara County to support a geohazard assessment of the Montecito area. This effort was led by the California Geological Survey, with the support of the California Department of Forestry and Fire Protection (CAL FIRE).(Credit: Donyelle K. Davis , USGS . Public domain.)              More Resources & Information                                         Post Wildfire, Flash Flood and Debris Flow Guide                      Post-Fire Debris-Flow Hazards Debris Flow Hazard in The United States Emergency Assessment of Post-Fire Debris Flow Hazards Southern California Landslides: An Overview Southern California—Wildfires and Debris Flows Learn More About Landslides Landslides 101 Real-time Monitoring for Potential Landslides What To Do and Look For During and Immediately After Heavy Rains Landslide Hazards Peligros de Deslizamientos #usgs #news

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Understanding the Mineral Resources of the Midcontinent Rift: Meet the Mid-Continent Rift, one of the most geologically fascinating regions in the United States and Canada.(Public domain.) Now, you too can learn some of that history and see a small part of the mineral potential of the United States without leaving your comfortable chair! The USGS has just released a new interactive Story Map describing the Mineral Deposits of the Midcontinent Rift System. The Midcontinent Rift System, which curves for more than 2000 km across the Upper Midwest, is one of the world’s great continental rifts. Rifting began about 1.1 billion years ago, when the Earth’s crust began to split along the margin of the Superior craton. Rifting ended before the crust completely opened to form a new ocean, and as time passed rift rocks were buried beneath younger rocks. With erosion and glaciation, the ancient rocks of the Midcontinent Rift were exposed in the Lake Superior region, creating much of its spectacular shoreline. Learn the geologic history behind the mining history in the Great Lakes.(Public domain.) In the Lake Superior region, rocks of the rift contain a wealth of mineral resources that formed by magmatic and hydrothermal processes during the ~30 million year course of rift development. Rift rocks are host to Michigan’s storied native copper deposits, and contain significant copper and nickel that were deposited during various stages of rift development. In this Story Map, mineral deposit locations and descriptions, compiled from the USGS Mineral Resource Data System and the Ontario Geological Survey Mineral Deposit Inventory, are categorized by mineral commodity, mineral deposit type, and the relative time frame of mineralization. The Midcontinent region is the focus of active mineral exploration, including for mineral deposit types previously unrecognized there.  Here, USGS scientists Laurel Woodruff and Suzanne Nicholson visit an anorthosite quarry, Duluth Complex, MN. Photo by K. Schulz, USGS.(Credit: Klaus, Schulz. Public domain.) This Story Map also describes a new comprehensive digital Geographic Information System for the Midcontinent Rift System recently compiled by the USGS from numerous regional studies conducted over the last several decades. Characterizing the mineral resources of the Midcontinent Rift System is a priority of the USGS Mineral Resources Program, and we hope you enjoy this Story Map that tells just part of the amazing story of this important geologic feature. Much of the Great Lakes' mineral wealth can be traced to the Mid-Continent Rift. Here is a generalized geologic map of the Midcontinent Rift System. Modified from Dean Peterson, Duluth Metals. (Public domain.) Read More: Multidisciplinary Studies to Image and Characterize the Mineral Resource Potential of the Midcontinent Rift, USA Geophysics of the Midcontinent Rift Region Characterization of the Midcontinent Region Mineral Resources #usgs #news

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Alaska Earthquake Rattles Florida’s Groundwater Plumbing: More than 3,500 miles from the Kodiak Earthquake’s epicenter, water levels at the USGS groundwater well near Madison, Florida, spiked by about two inches, while levels at the USGS groundwater well near Fort Lauderdale, Florida, dropped by an inch and a half. Both recovered to their previous levels within an hour. Hydrographs from two USGS groundwater monitoring sites in Florida show effects on groundwater levels from the M7.9 earthquake near Kodiak, Alaska. (Public domain.) Hydrogeologic responses to earthquakes have been known for decades, and have occurred both close to, and thousands of miles from earthquake epicenters. Water wells have become turbid, dry or begun flowing, discharge of springs and ground water to streams has increased and new springs have formed, and well and surface-water quality have become degraded as a result of earthquakes. This is not even the first time a major Alaska earthquake caused groundwater effects far from its original epicenter. Water-level fluctuations caused by the 1964 magnitude 8.5 Alaska earthquake were recorded in 716 wells in the United States; the earthquake also was registered on water-level recorders in many other countries. A map of USGS groundwater monitoring sites in Florida. Of the 606 current sites in Florida, 149 have real-time data. Visit here for more information. (Public domain.) What Happens? One common type of observed ground-water response is an instantaneous water-level offset, or step, which may be either an increase or a decrease and may occur near or far from the epicenter. Recovery to the pre-earthquake water level can be so rapid that no change will be detected if the water level is measured infrequently, or it may take as long as days or months. The other common type of ground-water response is a water-level oscillation, which may occur during many earthquakes, but is rarely recorded because they do not last long enough for many groundwater monitoring systems to record them. In the few cases where oscillations have been recorded, they resemble long-period seismograms. The change in water level can be small, measured in inches, or dramatic, measured in feet. However, the changes rarely exceed a couple of feet change. This map shows the intensity of shaking from the 2018 M7.9 earthquake near Kodiak, Alaska.  (Public domain.) So Why Does This Happen? For the changes seen near Madison and Ft. Lauderdale, they are likely oscillations caused by the seismic waves. Think of it as the ripples in a glass of water on a table when a truck drives by outside. Other causes for groundwater effects from earthquakes include the compaction of the overlying rock layer like what happens during liquefaction. That compaction can lead to temporary spikes in groundwater levels. Meanwhile drops in groundwater levels can be caused by the escape of gas from the rock layers. In a fractured rock environment, changes in groundwater levels can be caused by the unclogging, widening, or narrowing of a fracture, or the creation of new fractures. USGS monitors groundwater levels all over the country through its Groundwater Watch network. These wells are located in rural, suburban, and urban areas, and are monitored regularly. Some are even provide real-time data. In addition, USGS continues to study the effects of seismic activity throughout the United States. Read more: Earthquakes—Rattling the Earth’s Plumbing System USGS Groundwater Data for Florida USGS Earthquake Hazards Program USGS Groundwater Information #usgs #news

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ShakeAlert: The Path to West Coast Earthquake Early Warning: How a Few Seconds Can Save Lives and Property — Public Lecture: What: Illustrated presentation: ShakeAlert: The Path to West Coast Earthquake Early Warning Who: Doug Given, USGS Geophysicist and Earthquake Early Warning Coordinator When: Thursday, January 25, 2018 12:00 p.m. — Lecture preview for USGS employees and news media representatives. 1:00 p.m. — Speaker availability for news media interviews. 7:00 p.m.— Public lecture open to all. (Both presentations will be live-streamed online. There will be an archived video for later viewing.) Where: U.S. Geological Survey Rambo Auditorium, Bldg. 3, 2nd floor 345 Middlefield Road Menlo Park, Calif. (Public domain.)   #usgs #news

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Magnitude 7.9 Earthquake Gulf of Alaska: A magnitude 7.9 earthquake struck the Gulf of Alaska on January 23, 2018 at 12:32 am Alaska time (09:32UTC). Visit the USGS event page for more information. For estimates of casualties and damage, visit the USGS Prompt Assessment of Global Earthquakes for Response (PAGER) website. USGS regional map of the January 23, 2018 earthquake in the Gulf of Alaska(Public domain.) If you felt this earthquake, report your experience on the “USGS Did You Feel It?” website for this event. For information about tsunami watches, warnings or advisories, visit the National Oceanic and Atmospheric Administration (NOAA) tsunami website. The USGS operates a 24/7 National Earthquake Information Center in Colorado that can be reached for more information at 303-273-8500. Learn more about the USGS Earthquake Hazards Program #usgs #news

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Scientists, volunteers rescue about 1,000 cold-stunned sea turtles: When water temperatures drop below 50 degrees Fahrenheit (10 degrees Celsius), cold-blooded sea turtles, like this Kemp’s ridley, can become cold-stunned. They are unable to swim or even raise their heads out of the water to breathe, which can lead to drowning. Photo by Margaret Lamont, USGS (Public domain.) On the icy cold shores of Florida’s St. Joseph Bay, a team of volunteers and wildlife experts have rescued an estimated 1,000 cold-stunned sea turtles since January 2 in what is believed to be Florida’s second-largest mass cold-stunning event of the 21st century, according to U.S. Geological Survey research biologist Margaret Lamont. Lamont has been coordinating the turtle rescues in cooperation with the Florida Fish and Wildlife Conservation Commission. About 50 people – about 30 volunteers from the Florida Coastal Conservancy, employees of the U.S. Fish and Wildlife Service, Eglin Air Force Base, the Florida FWCC, Gulf World Marine Park, and two more USGS scientists – have taken part in the rescues Jan. 2-7, when about 700 turtles were rescued, and Jan. 17-19, when about 300 more were brought in. So many cold-stunned turtles have been rescued from the bay’s waters and mud flats that Gulf World, where the turtles are taken to rest and recover, is full and can only take in injured animals, she said. A rented house where Lamont and two scientists conduct their research was full of turtles, inside and outside, on Friday, Jan. 19.  The vast majority of the turtles rescued were threatened green turtles (Chelonia mydas), but the teams also brought in endangered Kemp's ridleys (Lepidochelys kempii), threatened loggerheads (Caretta caretta) and one endangered hawksbill (Eretmochelys imbricata). Scientists and volunteers use nets to scoop the immobile sea turtles out of St. Joseph Bay before transporting them to safety. Photo by USGS.  (Public domain.) “I’m very happy with how we’ve been able to minimize the mortality to the animals,” said Lamont, who has been studying sea turtles in Florida since 1995. “And I’m very proud of how everyone has come together to get it done. I’m especially proud of the volunteers who are out here in the cold and mud, doing exhausting work for no reward and often no recognition.” When water temperatures drop below 50 degrees Fahrenheit (10 degrees Celsius), cold-blooded sea turtles’ metabolisms slow so much that they become unable to swim or even lift their heads above the water to breathe. Without warmth or help, they drown. Every winter, when strong cold fronts sweep through the Florida Panhandle, volunteers and scientists rescue about 30 to 40 cold-stunned turtles. In 2010, a statewide cold snap led to the rescue of about 1,700 turtles, the largest such rescue in this century, Lamont said. This winter, so many animals have needed rescuing because the back-to-back cold spells have lasted so long. And middle-of-the-night low temperatures have coincided with high tides that washed the turtles into the shallows, Lamont said. St. Joseph Bay is home to a dense population of overwintering sea turtles, Lamont said. “It’s perfect habitat for them. It has some of the most pristine sea grass beds in Florida where they can feed, cut through by deep channels where they can escape from predators,” she said. In cold weather, turtles normally leave the shallows for deeper water that doesn’t turn cold so quickly – but if the cold lasts long enough, even those depths can fall below 50 degrees. Meanwhile strong winds can blow the sea turtles onto the coastal mudflats where they become stranded. Eglin Air Force Base biologist Kathy Gault (left) and USGS biologist Dave Seay (right) hauled cold-stunned sea turtles to safety along the icy shore of Cape San Blas. Scientists and licensed volunteers walked the beaches and marshes, loading cold-stunned sea turtles into kayaks. Once full, kayaks could weigh more than 400 pounds and had to be dragged two to three miles to shoreline access points. Photo by Margaret Lamont, USGS. (Public domain.) USGS scientist Margaret Lamont measures a Kemp’s ridley sea turtle recovered from the cold waters of St. Joseph Bay. Rescued sea turtles are weighed, measured and marked with an identifier, and are examined to determine if they need medical attention. Photo by USGS. (Public domain.) The rescue teams work by boat, with USGS, USFWS and Florida FWCC scientists using nets to scoop cold-stunned turtles out of the bay, and on foot. On the bay’s Cape San Blas, teams of scientists, wildlife workers and specially-trained and licensed volunteers walk the beaches and marshes, picking up cold-stunned turtles from the shoreline and loading them onto kayaks. When fully loaded with turtles, the kayaks may weigh 400 pounds or more, “and the only access points are two or three miles apart,” Lamont said. “So people are out there in the cold and mud, with harnesses around their chests, pulling the kayaks across the mud flats,” Lamont said. “It’s exhausting. It’s really tough. And it’s really inspiring to see that people are willing to do it to save these animals.” The turtles are weighed, measured, and marked with an identifier, and examined to determine whether they need medical care. If they don’t, a few hours in sunlight or another warm space is usually enough to revive them, Lamont said. Warmer weather was due to return on the night of Friday, January 19, so Lamont expected the rescues to end that evening. Weather permitting, most of the turtles sheltering at Gulf World Marine Park were scheduled to be released back into bay waters on Saturday, January 20, according to the marine park. USGS scientist Margaret Lamont, who has studied sea turtles in Florida since 1995, carries a cold-stunned green sea turtle from the mud flats of St. Joseph Bay. Photo by USGS. (Public domain.) USGS scientist David Seay holds a green sea turtle that is recovering from the effects of cold-stunning in St. Joseph Bay. Photo by Margaret Lamont, USGS. (Public domain.)   #usgs #news
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