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Organic geochemical investigation of far‐field tsunami deposits of the Kahana Valley, O'ahu, Hawai'i Organic geochemical investigation of far‐field tsunami deposits of the Kahana Valley, O'ahu, Hawai'i

Far‐field tsunami deposits observed in the Kahana Valley, O'ahu, Hawai'i (USA), were investigated for their organic‐geochemical content. During short high‐energy events, (tsunamis and storms) organic and chemical components are transported with sediment from marine to terrestrial areas. This study investigates the use of anthropogenic based organic geochemical compounds (such as...
Authors
Piero Bellanova, Mike Frenken, Bruce M. Richmond, Jan Schwarzbauer, SeanPaul La Selle, Frances Griswold, Bruce E. Jaffe, Alan R. Nelson, Klaus Reicherter

Unravelling the complexity of magma plumbing at Mount St. Helens: A new trace element partitioning scheme for amphibole Unravelling the complexity of magma plumbing at Mount St. Helens: A new trace element partitioning scheme for amphibole

Volcanoes at subduction zones reside above complex magma plumbing systems, where individual magmatic components may originate and interact at a range of pressures. Because whole-rock compositions of subduction zone magmas are the integrated result of processes operating throughout the entire plumbing system, processes such as mixing, homogenisation and magma assembly during shallow...
Authors
Madeleine C. S. Humphreys, George F. Cooper, Jing Zhang, Matthew W. Loewen, Adam J. R. Kent, Colin G. Macpherson, Jon P. Davidson

Marshes are the new beaches: Integrating sediment transport into restoration planning Marshes are the new beaches: Integrating sediment transport into restoration planning

Recent coastal storms and associated recovery efforts have led to increased investment in nature-based coastal protection, including restoration of salt marshes and construction of living shorelines. In particular, many of these efforts focus on increasing vertical elevation through sediment nourishment, where sediment is removed from the tidal channel and placed on the marsh plain, or...
Authors
Neil K. Ganju

Rayleigh wave ellipticity measurement uncertainty across the IRIS/USGS and New China Digital Seismograph Networks Rayleigh wave ellipticity measurement uncertainty across the IRIS/USGS and New China Digital Seismograph Networks

Long-period Rayleigh wave horizontal to vertical amplitude (H/V) ratios at a station provide information about local earth structure that is complementary to phase velocity. However, a number of studies have observed that significant scatter appears in these measurements making it difficult to use H/V ratio measurements to resolve earth structure. Some of the scatter in these...
Authors
Adam T. Ringler, David C. Wilson, Walter Zurn, Robert E. Anthony

Azimuthal seismic anisotropy of 70 Ma Pacific‐plate upper mantle Azimuthal seismic anisotropy of 70 Ma Pacific‐plate upper mantle

Plate formation and evolution processes are predicted to generate upper mantle seismic anisotropy and negative vertical velocity gradients in oceanic lithosphere. However, predictions for upper mantle seismic velocity structure do not fully agree with the results of seismic experiments. The strength of anisotropy observed in the upper mantle varies widely. Further, many refraction...
Authors
H. F. Mark, D. Lizarralde, J. A. Collins, Nathaniel C. Miller, G. Hirth, J. B. Gaherty, R. L. Evans

Four major Holocene earthquakes on the Reelfoot fault recorded by sackungen in the New Madrid seismic zone, USA Four major Holocene earthquakes on the Reelfoot fault recorded by sackungen in the New Madrid seismic zone, USA

Three sequences of well-documented, major ~M7+ earthquakes (1811-1812 CE, ~1450 CE, and ~900 CE) in the New Madrid seismic zone, USA, contribute significantly to seismic hazard in the region. However, it is unknown whether this
Authors
Ryan D. Gold, Christopher DuRoss, Jaime E. Delano, Randall W. Jibson, Richard W. Briggs, Shannon A. Mahan, Robert Williams, D. Reide Corbett

Water salinity and inundation control soil carbon decomposition during salt marsh restoration: An incubation experiment Water salinity and inundation control soil carbon decomposition during salt marsh restoration: An incubation experiment

Coastal wetlands are a significant carbon (C) sink since they store carbon in anoxic soils. This ecosystem service is impacted by hydrologic alteration and management of these coastal habitats. Efforts to restore tidal flow to former salt marshes have increased in recent decades and are generally associated with alteration of water inundation levels and salinity. This study examined the...
Authors
Faming Wang, Kevin D. Kroeger, Meagan Gonneea Eagle, John W. Pohlman, Jianwu Tang

Clastic pipes and mud volcanism across Mars: Terrestrial analog evidence of past Martian groundwater and subsurface fluid mobilization Clastic pipes and mud volcanism across Mars: Terrestrial analog evidence of past Martian groundwater and subsurface fluid mobilization

Clastic pipes are cylindrical injection features that vertically crosscut bedding with sharp contacts. Terrestrial pipes have cylindrical morphologies, massive or radially graded interiors, and raised outer rims. Increased grain size and subsequent cementation along the more porous edges makes the rims more resistant to weathering. Pipes have crosscutting relationships with other pipes...
Authors
D. F. Wheatley, M. A. Chan, Chris Okubo

Landslides triggered by Hurricane Maria: Assessment of an extreme event in Puerto Rico Landslides triggered by Hurricane Maria: Assessment of an extreme event in Puerto Rico

Hurricane Maria hit the island of Puerto Rico on 20 September 2017 and triggered more than 40,000 landslides in at least three-fourths of Puerto Rico’s 78 municipalities. The number of landslides that occurred during this event was two orders of magnitude greater than those reported from previous hurricanes. Landslide source areas were commonly limited to surficial soils but also...
Authors
Erin Bessette-Kirton, Corina Cerovski-Darriau, William H. Schulz, Jeffrey A. Coe, Jason W. Kean, Jonathan W. Godt, Matthew A. Thomas, K. Stephen Hughes

Evaluation of temporally correlated noise in global navigation satellite system time series: Geodetic monument performance Evaluation of temporally correlated noise in global navigation satellite system time series: Geodetic monument performance

Estimates of background noise of Global Positioning System‐derived time series of positions for 740 sites in the western United States are examined. These data consist of daily epochs of three components of displacements that are at least 9.75 years long within the interval between 2000 and 2018. We find that these time series have significant temporal correlations that could be...
Authors
John Langbein, Jerry L. Svarc

The compositions of the lunar crust and upper mantle: Spectral analysis of the inner rings of lunar impact basins The compositions of the lunar crust and upper mantle: Spectral analysis of the inner rings of lunar impact basins

The innermost ring in impact basins exposes material originating from various depths, and can be used to study the composition of the lunar crust with depth. In this study, we conduct quantitative mineralogical analyses of the innermost ring in 13 lunar impact basins using reflectance data from the Kaguya Multiband Imager and radiative transfer modeling. We use results from recent...
Authors
Myriam Lemelin, Paul G. Lucey, Katarina Miljkovic, Lisa R. Gaddis, Trent M. Hare, Makiko Ohtake

The formation of gullies on Mars today The formation of gullies on Mars today

A decade of high-resolution monitoring has revealed extensive activity in fresh Martian gullies. Flows within the gullies are diverse: they can be relatively light, neutral or dark, colourful or bland, and range from superficial deposits to 10 m-scale topographic changes. We observed erosion and transport of material within gullies, new terraces, freshly eroded channel segments...
Authors
Colin M. Dundas, Alfred S. McEwen, Serina Diniega, Candice J. Hansen, Jim N. McElwaince
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