USGS News

Landslides Triggered by Nepal Earthquakes

Summary: A new report from the U.S. Geological Survey provides critical landslide-hazard expertise to Nepalese agencies and villages affected by the April 25, magnitude 7.8 earthquake that shook much of central Nepal A Scientific Look at What Happened and What Could Happen this Monsoon Season

Contact Information:

Dave Frank ( Phone: (509) 368-3107 ); Leslie Gordon ( Phone: (650) 329-4006 );



Villagers in Kerauja, Nepal standing below a large rock slide that resulted in one fatality. (high resolution image 8.7 MB)

MENLO PARK, Calif. — A new report from the U.S. Geological Survey provides critical landslide-hazard expertise to Nepalese agencies and villages affected by the April 25, magnitude 7.8 earthquake that shook much of central Nepal. The earthquake and its aftershocks triggered thousands of landslides in the steep topography of Nepal, and caused nearly 8,900 fatalities. Hundreds of those deaths were due to landslides, which also blocked vital road and trail lifeline routes to affected villages.

Landslides caused by the earthquakes continue to pose both immediate and long-term hazards to villages and infrastructure within the affected region. Several landslides blocked rivers, creating temporary dams, which were a major concern for villages located downstream. The report provides a rapid assessment of landslide hazards for use by Nepalese agencies during this current monsoon season.

With support from the U.S. Agency for International Development’s Office of U.S. Foreign Disaster Assistance, and in collaboration with earthquake-hazard organizations from both the United States and Nepal, the USGS responded to this landslide crisis by providing expertise to Nepalese agencies and affected villages. In addition to collaborating with an international group of remote-sensing scientists to document the extent and spatial distribution of landsliding in the first few weeks following the earthquake, the USGS conducted in-country landslide hazard assessments for 10 days in May and June. Much of the information obtained by the USGS in Nepal was conveyed directly to affected villages and government agencies as opportunities arose. Upon return to the United States, data organization, interpretation and synthesis immediately began in order to publish a final report.

This new report provides a detailed account of the assessments performed in May and June, with a particular focus on valley-blocking landslides because they have the potential to pose considerable hazard to many villages in Nepal. The results include an overview of the extent of landsliding, a presentation of 74 valley-blocking landslides identified during the work, and a description of helicopter-based video resources that provide over 11 hours of high resolution footage of approximately 1,000 km (621 miles) of river valleys and surrounding areas affected by the earthquakes. A description of site-specific landslide-hazard assessments conducted while in Nepal and detailed descriptions of five noteworthy case studies are also included. The report ends with an assessment of the expectation for additional landslide hazards in the summer monsoon season following the earthquakes.

The full report, USGS OFR 2015-1142, “Assessment of Existing and Potential Landslide Hazards Resulting from the April 25, 2015 Gorkha, Nepal Earthquake Sequence” is available online, as well as the video footage collected during the research.

Aerial photographs showing landslides triggered by the April and May 2015 Gorkha earthquake sequence in central Nepal. A, Widespread ridgetop landsliding in Gorkha district. The Kerauja rock slide (cover image of report) is wide scar on ridge visible in photograph background (arrow). B, Partially breached Gogane landslide dam in Rasuwa district of Nepal. Top of scarp below village (arrow) is approximately 400 m above river level. C, Rock falls in the Urkin Kangari Valley, Sindhupalchok district. Image shows approximately 1,200 m relief between top of foreground cliffs and valley floor. (high resolution image 3 MB) Photographs showing the Langtang, Nepal debris avalanche, which destroyed the entire village of Langtang. An estimated 200 people were killed in this single event. A, Oblique northwest view of deposit with cliff in which the debris became airborne. Homes in foreground were pushed over by the ensuing airblast. B, Aerial view of debris avalanche deposit showing location of the Langtang River tunnel through ice and debris. (high resolution image 2.2 MB)

New Magnolia State Maps Adding Trails

Summary: Several of the 772 new US Topo quadrangles for Mississippi now display parts of the Natchez Trace National Scenic Trail and other selected public trails. Further significant additions to the new quadrangles include map symbol redesign, enhanced railroad information and new road source data Newly released US Topo maps for Mississippi now feature selected trails and other substantial updates

Contact Information:

Mark Newell, APR ( Phone: 573-308-3850 ); Larry Moore ( Phone: 303-202-4019 );



Several of the 772 new US Topo quadrangles for Mississippi now display parts of the Natchez Trace National Scenic Trail and other selected public trails. Further significant additions to the new quadrangles include map symbol redesign, enhanced railroad information and new road source data. For Gulf Coast residents, recreationalists and visitors who want to explore the featured Mississippi trails by biking, hiking, horseback or other means, the new trail features on the US Topo maps will be useful.

Historically, the 450-mile foot trail that became known as the Natchez Trace was the lifeline through the Old Southwest. The Old Natchez Trace footpath ran through Choctaw and Chickasaw lands, connecting Natchez, Mississippi, to Nashville, Tennessee. Today, the current trail network consists of five separate trails totaling more than 60 miles.

"The inclusion of the Natchez Trace National Scenic Trail onto the US Topo maps will be an excellent tool for publicizing the trail to visitors,” said Greg Smith, Natchez Trace National Scenic Trail Coordinator for the National Park Service. “ The trail traverses three states and provides an opportunity for users to experience the unique cultural and natural aspects of the Old Natchez Trace."

The USGS partnered with the National Park Service to incorporate the trail data onto the Mississippi US Topo maps. The Natchez Trace National Scenic Trail joins the Ice Age National Scenic Trail, the Pacific Northwest National Scenic Trail the North Country National Scenic Trail, Pacific Crest National Scenic Trail, and the Arizona National Scenic Trail as being featured on the new US Topo quads. The USGS plans to eventually include all National Scenic Trails in The National Map products.

Some of the other data for new trails on the maps is provided to the USGS through a nationwide “crowdsourcing” project managed by the International Mountain Biking Association (IMBA).  This unique crowdsourcing venture has increased the availability of trail data available through The National Map mobile and web apps, and the revised US Topo maps.

During the past two years the IMBA, in a partnership with the MTB Project, has been building a detailed national database of trails. This activity allows local IMBA chapters, IMBA members, and the public to provide trail data and descriptions through their website. MTB Project and IMBA then verify the quality of the trail data provided, ensure accuracy and confirm the trail is legal. 

These new maps replace the first edition US Topo maps for the Magnolia State and are available for free download from The National Map, the USGS Map Locator & Downloader website, or several other USGS applications

To compare change over time, scans of legacy USGS topo maps, some dating back to the late 1800s, can be downloaded from the USGS Historical Topographic Map Collection

For more information on US Topo maps: http://nationalmap.gov/ustopo/

Updated 2015 version of Tupelo, Mississippi US Topo quadrangle with orthoimage turned on. (1:24,000 scale). (high resolution image 1.4 MB) Scan of the 1921 legacy topographic map quadrangle of the Tupelo, Mississippi area from the USGS Historic Topographic Map Collection. (high resolution image 2 MB) Updated 2015 version of Tupelo, Mississippi US Topo quadrangle with orthoimage turned off. (1:24,000 scale) (high resolution image 1.2 MB)

The National Trails System was established by Act of Congress in 1968. The Act grants the Secretary of Interior and the Secretary of Agriculture authority over the National Trails System.  The Act defines four types of trails. Two of these types, the National Historic Trails and National Scenic Trails, can only be designated by Act of Congress.  National scenic trails are extended trails located as to provide for maximum outdoor recreation potential and for the conservation and enjoyment of nationally significant scenic, historic, natural, and cultural qualities of the area through which such trails may pass.

There are 11 National Scenic Trails:

  • Appalachian National Scenic Trail
  • Pacific Crest National Scenic Trail
  • Continental Divide National Scenic Trail
  • North Country National Scenic Trail
  • Ice Age National Scenic Trail
  • Potomac Heritage National Scenic Trail
  • Natchez Trace National Scenic Trail
  • Florida National Scenic Trail
  • Arizona National Scenic Trail
  • New England National Scenic Trail
  • Pacific Northwest National Scenic Trail

Media Advisory: Cascadia Quake and Orphan Tsunami — Public Lecture

Summary: One winter's night in the year 1700, a mysterious tsunami flooded fields and washed away houses in Japan. It arrived without the warning that a nearby earthquake usually provides

Contact Information:

Leslie Gordon ( Phone: 650-329-4006 );



MENLO PARK, Calif. — One winter's night in the year 1700, a mysterious tsunami flooded fields and washed away houses in Japan. It arrived without the warning that a nearby earthquake usually provides. Samurai, merchants and villagers wrote of the event, but nearly three centuries would pass before geological discoveries linked the tsunami to the subduction zone that runs along the Pacific coast of southern British Columbia, Washington, Oregon and northern California. Today, this Trans-Pacific detective story guides preparations for future earthquakes and tsunamis in North America's Cascadia region. 

What:

Illustrated presentation: “The Giant Cascadia Earthquake of January 26, 1700: Detective Stories from North America and Japan

Who:

Brian Atwater, USGS geologist

When:

Thursday, July 30, 2015

12:00 p.m. — Lecture preview for USGS employees and news media representatives

7:00 p.m.— Public lecture open to all

(Both presentations will be live-streamed online, and archived for later viewing.)

Where:

U.S. Geological Survey
Rambo Auditorium, Bldg. 3, 2nd floor
345 Middlefield Road
Menlo Park, Calif.

Book:

The Orphan Tsunami of 1700—Japanese Clues to a Parent Earthquake in North America

Breeding Bird Distribution Affected by Wind Turbines in the Dakotas

Summary: New wind energy facilities placed in prime wildlife habitat in North and South Dakota can influence the distribution of several species of grassland birds for years after construction, including species whose populations are in serious decline

Contact Information:

Jennifer LaVista ( Phone: 303-202-4764 ); Jill Shaffer ( Phone: 701-253-5547 );



New wind energy facilities placed in prime wildlife habitat in North and South Dakota can influence the distribution of several species of grassland birds for years after construction, including species whose populations are in serious decline.

According to a U.S. Geological Survey report recently published in the journal Conservation Biology, seven of nine bird species studied from 2003-2012, including the significantly declining grasshopper sparrow and bobolink, were displaced from suitable breeding habitat in native mixed-grass prairies after wind turbine construction. Displacement typically started one year after construction and persisted for at least two to five years.

One species, the killdeer, was temporarily attracted to the new wind facilities, likely because it prefers the gravel of turbine pads and roads for nesting. Neither displacement nor attraction was detected for one species, the vesper sparrow.

“Understanding how wind turbines affect breeding birds can help wind developers and land managers site turbines in areas with minimal impact to birds, while striving to meet energy demands, reduce carbon emissions and provide energy security,” said Jill Shaffer, a USGS scientist and lead author of the study.

The scientists collected data from three wind facilities in grasslands of Highmore, South Dakota, and Forbes and Oliver County, North Dakota. They monitored changes in density of breeding bird pairs overall and in relation to distance from wind turbines.

Two of the bird species exhibited displacement the year after construction, which persisted for at least two to five years:

  • The western meadowlark, which moved 300 to 1000 meters (m) from turbines, or more than 984 to 3280 feet (ft) and
  • the upland sandpiper (100 m, about 328 ft).

Species that exhibited displacement from two to five years post-construction were:

  • The bobolink (300 to 1000 m),
  • grasshopper sparrow (300 m),
  • clay-colored sparrow (200 m or 656 ft),
  • chestnut-collared longspur (300 m) and
  • savannah sparrow (300 m).

“The Great Plains supports some of the last remaining native temperate grasslands in North America,” Shaffer said. “Proper management of these valuable wildlife habitats can help maintain overall ecosystem health for the benefit of animals and people.”

The USGS and NextEra Energy provided research funding. For more information about wildlife habitat research in the Great Plains, please visit the USGS Northern Prairie Wildlife Research Center website.

New Groundwater Model Provides Better Understanding of Edwards Aquifer

Summary: Scientists have a better understanding of how water flows throughout the San Antonio, Texas, segment of the Edwards aquifer because of a new U.S. Geological Survey groundwater flow model, developed in cooperation with San Antonio Water System.

Contact Information:

Jennifer LaVista ( Phone: 303-202-4764 ); Linzy Brakefield ( Phone: 512-927-3529 );



Scientists have a better understanding of how water flows throughout the San Antonio, Texas, segment of the Edwards aquifer because of a new U.S. Geological Survey groundwater flow model, developed in cooperation with San Antonio Water System.

The Edwards aquifer is one of the most prolific aquifers in the world and it provides more than 50 percent of the drinking water consumed in the San Antonio and Austin areas. The aquifer supplies water to south-central Texas for residential, recreational, industrial and agricultural uses. Several endangered and threatened species are also sustained by groundwater discharged at Comal, San Marcos and Barton Springs.

“Understanding how groundwater moves is critical in order for decision makers to protect this finite resource,” said Darren Thompson, Director of Water Resources at San Antonio Water System. “You can’t manage what you don’t measure.”

The focus of the new USGS model is to simulate the interaction between freshwater, saline (salt) water and where the two mix, called the brackish-water transition zone. Model results indicate that effects on fresh water during a severe drought, such as the drought-of-record during 1950-56, would be minor.

This model improves on a previous USGS model that did not include analysis of the transition or saline zones. While this new model is capable of making predictions of spring flow, salinity concentrations and water levels in nearby wells, the reliability of these predictions are also measured through use of a tool known as uncertainty analysis, which few groundwater modeling studies currently provide. The model, coupled with uncertainty analysis, improves understanding of the potential effects of severe drought on the movement of water within and between the different water-quality zones.

“While the model shows little potential for movement of brackish water into freshwater, the research suggests there is a need for an improved understanding of some parts of the Edwards aquifer flow system,” said USGS scientist Linzy Brakefield. “Better knowledge of how the aquifer is recharged and the relationship between recharge, pumping and springflow is needed. With the new developments from this study there is potential to develop more accurate models in the future.” The full USGS report on the model is available online.

Mount McKinley Elevation Survey Results Coming Soon

Summary: A team of four climbers has recently returned from the highest point in North America with new survey data to determine a more precise summit height of Mount McKinley. It is anticipated the new elevation finding will be announced in late August Climbers return from the top of Mount McKinley to begin data analysis

Contact Information:

Mark Newell, USGS ( Phone: 573-308-3850 ); Sue Mitchell, UAF GI ( Phone: 907-474-5823 ); Vicki Childers, NOAA/NGS ( Phone: 301-713-3211 x161 );



A team of four climbers has recently returned from the highest point in North America with new survey data to determine a more precise summit height of Mount McKinley. It is anticipated the new elevation finding will be announced in late August.

The ability to establish a much more accurate height has grown with advances in surveying technologies since 1953 when the last official survey of Mount McKinley was recorded. The new elevation will eventually replace the formerly accepted elevation of 20,320 feet.

”Determining an updated elevation for the summit of Mount McKinley presents extraordinary challenges,” said Suzette Kimball, acting director of the USGS.  “The USGS and its partners are using the best available modern GPS survey equipment and techniques to ensure the new elevation will be determined with a high level of accuracy and confidence.”

Unique circumstances and variables such as the depth of the snow pack and establishing the appropriate surface that coincides with mean sea level must be taken into account before the new Mount McKinley elevation can be determined.

In 2013, an elevation was calculated for Mount McKinley using a technology known as Interferometric Synthetic Aperture Radar (ifsar). The 2013 elevation was slightly lower than the summit’s 20,320 foot height. Ifsar is an extremely effective tool for collecting map data in challenging areas such as Alaska, but it does not provide precise spot or point elevations. This new survey used GPS instruments that were placed directly on the summit to measure a specific point on the surface, thus giving a more defined spot elevation. 

The USGS, along with NOAA’s National Geodetic Survey (NGS), and the University of Alaska Fairbanks (UAF), are the primary partners supporting the survey of McKinley’s summit. The survey party included three GPS experts and mountaineers from CompassData (a subcontractor for Dewberry), and a scientist/climber from UAF’s Geophysical Institute.

Now that the data collection expedition is completed, the NGS, UAF, USGS and CompassData are in the process of analyzing the data.

"CompassData was honored to help the USGS and NOAA on this nationally important project,” said Blaine Horner, a member of the climbing team. “Our experience surveying around the world put us in a unique position to perform this work."

The team began their ascent, with the needed scientific instruments in tow, on June 16. With diligent work and mostly favorable weather, the team safely returned to their starting point ahead of schedule.

"We had nearly perfect weather on the mountain,” said Tom Heinrichs, Director of the UAF Geographic Information Network of Alaska and part of the climbing team. “The logistics on the mountain all went well. The summit survey was successful and our preliminary look at the data indicates we will get a good solution for the summit elevation."

Mount McKinley is part of Denali National Park. The Park hosts more than 530,000 visitors each year, with about 1,200 who attempt to climb Mount McKinley. In a typical year, about half of those who begin a McKinley climb reach the summit. The six million acre park will celebrate its 100th anniversary in 2017. The mountain was first summited in 1913.

Agustin (Udi) Karriere (front) and Rhett Foster from CompassData establishing the 11,000 foot camp, preparing to move to the next camp and summit ascent. (Photo: Tom Heinrichs, UAF) (Larger image) Rhett Foster from CompassData on a ridge leading to the 17,000 foot base camp. (Photo: Tom Heinrichs, UAF) (Larger image) Tom Heinrichs from the University of Alaska Fairbanks and Agustin (Udi) Karriere from CompassData traveling low on the mountain towards the next base camp, towing needed science and camp equipment. (Photo: Rhett Foster, CompassData) (Larger image) On top of North America! Blaine Horner from CompassData poses with GPS equipment on the top of Mount McKinley. (Photo: Agustin Karriere, CompassData) (Larger image)

Climate Change Reduces Coral Reefs' Ability to Protect Coasts

Summary: Coral reefs, under pressure from climate change and direct human activity, may have a reduced ability to protect tropical islands against wave attack, erosion and salinization of drinking water resources, which help to sustain life on those islands

Contact Information:

Mariska  van Gelderen, Deltares ( Phone: +31 (0)6 13 67 13 70 ); Leslie Gordon, USGS ( Phone: 650-329-4006 ); Nanci  Bompey, AGU ( Phone: 202-777-7524 );



Aerial photograph of Kwajalein Atoll showing its low-lying islands and coral reefs. (High resolution image) Aerial photograph of Kwajalein Atoll showing its low-lying islands and coral reefs. (High resolution image)

SANTA CRUZ, Calif. — Coral reefs, under pressure from climate change and direct human activity, may have a reduced ability to protect tropical islands against wave attack, erosion and salinization of drinking water resources, which help to sustain life on those islands. A new paper by researchers from the Dutch independent institute for applied research Deltares and the U.S. Geological Survey gives guidance to coastal managers to assess how climate change will affect a coral reef’s ability to mitigate coastal hazards.  

About 30 million people are dependent on the protection by coral reefs as they live on low-lying coral islands and atolls. At present, some of these islands experience flooding due to wave events a few times per decade. It is expected that this rate of flooding will increase due to sea level rise and coral reef decay, as the remaining dead corals are generally smoother in structure, and do less to dissipate wave energy. Loss of coral cover not only causes increased shoreline erosion but also affects the sparse drinking water resources on these islands, which may eventually make these islands uninhabitable.  In order to prevent or mitigate these impacts, coastal managers need know to what extent their reef system may lose its protective function so that they can take action. The new study gives guidance on a local reef’s sensitivity to change. The new research has been accepted for publication in “Geophysical Research Letters,” a journal of the American Geophysical Union.

To gain insight into effects of changing conditions on coral reefs, the study authors used Xbeach (an open-source wave model). The computer model was first validated using field measurements obtained on the Kwajalein Atoll in the Marshall Islands in the Pacific Ocean, and was then used to investigate what the effects on water levels, waves, and wave-driven runup would be if certain reef properties change. Reef roughness, steepness, width and the total water level on the reef platform are all important factors for coastal managers to consider when planning mitigating measures.

The results suggest that coasts fronted by relatively narrow reefs with steep faces and deeper, smoother reef flats are expected to experience the highest wave runup and thus potential for island flooding. Wave runup increases for higher water levels (that are expected with sea level rise), higher waves, and lower bed roughness (as coral degrades and becomes smoother), which are all expected effects of climate change. Rising sea levels and climate change will have a significant negative impact on the ability of coral reefs to mitigate the effects of coastal hazards in the future.

The research paper, “The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines,” is published as an open-access paper and available online.

Quataert, E., C. Storlazzi, A. van Rooijen, O. Cheriton, and A. van Dongeren (2015), The influence of coral reefs and climate change on wave-driven flooding of tropical coastlines, Geophysical Research Letters, 42, doi:10.1002/2015GL064861

Deltares is an independent institute for applied research in the field of water and subsurface. Visit http://www.deltares.nl and follow us on Twitter @deltares or LinkedIn.

Detailed Flood Information Key to More Reliable Coastal Storm Impact Estimates

Summary: CORAM, N.Y. -- A new study that looked in part at how damage estimates evolve following a storm puts the total amount of building damage caused by Hurricane Sandy for all evaluated counties in New York at $23 billion. Study Looks at NY Sandy Impacts and Losses by County

Contact Information:

Christopher  Schubert ( Phone: 631-736-0783 x109 ); Ronald  Busciolano ( Phone: 631-736-0783 x104 ); Vic  Hines ( Phone: 813-855-3125 );



CORAM, N.Y. -- A new study that looked in part at how damage estimates evolve following a storm puts the total amount of building damage caused by Hurricane Sandy for all evaluated counties in New York at $23 billion. Estimates of damage by county ranged from $380 million to $5.9 billion.

The U.S. Geological Survey study, done in cooperation with the Federal Emergency Management Agency, marks the first time the agency has done this type of analysis and cost estimation for a coastal storm.

"We looked at how estimates of building damage change depending on the amount of information available at the time of the estimate, looking at three time periods -- storm landfall, two weeks later, and then three months later," said Chris Schubert, a USGS hydrologist and lead author of the study. "What we found was that the biggest jump in estimate reliability comes between the initial estimate and the two-week mark, but that the additional information available three months after an event greatly help refine the estimates even further."

The USGS researcher called the study a "proof of concept" that really showcased the value of gathering storm data before and after a storm.

"FEMA funded the sensor placement we did prior to the storm and our assessment of how high the water reached after the storm," Schubert said. "The results from this new study demonstrated how the additional resolution and accuracy of flood depictions resulting from these efforts greatly improved the damage estimates."

Damage estimates can be used by FEMA and other stakeholders to help prioritize relief and reconstruction efforts following a storm. The results can also assist with resiliency planning that helps communities prepare for future storms.

The researchers came up with the estimates by using census data and FEMA’s HAZUS modeling software program.  The HAZUS program is used to estimate potential loss from disasters such as earthquakes, wind, hurricanes and floods.  This program allows for an assessment of building loss on a block-by-block level.

Hurricane Sandy’s impact was the first time in recent memory, and record, that coastal water levels had reached the heights they attained in many places in the state of New York. Flood effects of Hurricane Sandy, in comparison to those from Tropical Storm Irene in 2011, were significantly more extensive, with most water levels rising at least 2.5 feet higher than in the 2011 storm.

With the latest USGS analysis, a comprehensive picture of the magnitude of Sandy’s impact is now available. Without the sensor placement before the storm, and assessment of high-water marks after, this level of understanding wouldn’t be possible.

"This is the first time USGS has done this type of analysis and cost estimation for a coastal storm," said Schubert. "The effort incorporates what we learned from previous storms going back to Katrina, and the storm-tide information we provided to FEMA in the immediate aftermath of Sandy is one of the building blocks for this research. The additional fidelity of the damage estimate underscores the tremendous value of the dataset for this storm."

Interpretation of storm-tide data from a variety of tools such as tide gauges, stream gauges, and temporary sensors combined with high-water marks showed the extreme nature of storm-tide flooding and, at some sites, the severity and arrival time of the storm surge.  Storm surge is the height of water above the normal astronomical tide level due to a storm. Storm tide is the storm surge in addition to the regular tide.

"Timing matters, though every storm is different," said Schubert. "Throughout southeastern New York, we saw that timing of the surge arrival determined how high the storm tide reached. The worst flooding impacts occurred along the Atlantic Ocean-facing parts of New York City and western Long Island, where the peak storm surge arrived at high tide. So the resulting storm tide was five to six feet higher than it would have been had the peak surge arrived at low tide."

The new research is available online in, Analysis of Storm-Tide Impacts from Hurricane Sandy in New York, SIR 2015-5036, by C.E. Schubert, R. Busciolano, P.P. Hearn Jr., A.N. Rahav, R. Behrens, J. Finkelstein, J. Monti Jr., and A. E. Simonson. It examined damage estimates from those counties with depictions of flood extent available from FEMA and the National Hurricane Center.

The USGS is also conducting a study in New Jersey that examines similar topics, including the estimated flood frequency of documented peak storm-tide elevations, comparisons of Sandy to historic coastal storms, the timing of storm surge, and changes in HAZUS damage estimates with the use of USGS sensor and high-water-mark data.   That study is expected to be completed and released later this year.