Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 9 of 9
Full-Text Articles in Geological Engineering
Early Warning System For Shallow Landslides Using Rainfall Threshold And Slope Stability Analysis, Shruti Naidu, K. S. Sajinkumar, Thomas Oommen, V.J. Anuja, Rinu Samuel, C. Muraleedharan
Early Warning System For Shallow Landslides Using Rainfall Threshold And Slope Stability Analysis, Shruti Naidu, K. S. Sajinkumar, Thomas Oommen, V.J. Anuja, Rinu Samuel, C. Muraleedharan
Michigan Tech Publications
A combined cluster and regression analysis were performed for the first time to identify rainfall threshold that triggers landslide events in Amboori, Kerala, India. Amboori is a tropical area that is highly vulnerable to landslides. The 2, 3, and 5-day antecedent rainfall data versus daily rainfall was clustered to identify a cluster of critical events that could potentially trigger landslides. Further, the cluster of critical events was utilized for regression analysis to develop the threshold equations. The 5-day antecedent (x-variable) vs. daily rainfall (y-variable) provided the best fit to the data with a threshold equation of …
Atmospheric Processes Affecting The Separation Of Volcanic Ash And So < Inf> 2 In Volcanic Eruptions: Inferences From The May 2011 Grímsvötn Eruption, Fred Prata, Mark Woodhouse, Herbert E. Huppert, Andrew Prata, Thor Thordarson, S. Carn
Atmospheric Processes Affecting The Separation Of Volcanic Ash And So < Inf> 2 In Volcanic Eruptions: Inferences From The May 2011 Grímsvötn Eruption, Fred Prata, Mark Woodhouse, Herbert E. Huppert, Andrew Prata, Thor Thordarson, S. Carn
Michigan Tech Publications
The separation of volcanic ash and sulfur dioxide (SO2) gas is sometimes observed during volcanic eruptions. The exact conditions under which separation occurs are not fully understood but the phenomenon is of importance because of the effects volcanic emissions have on aviation, on the environment, and on the earth's radiation balance. The eruption of Grímsvötn, a subglacial volcano under the Vatnajökull glacier in Iceland during 21-28 May 2011 produced one of the most spectacular examples of ash and SO2 separation, which led to errors in the forecasting of ash in the atmosphere over northern Europe. Satellite data from several sources …
A Novel Applications Of Photogrammetry For Retaining Wall Assessment, Renee Oats, Rudiger Escobar-Wolf, Thomas Oommen
A Novel Applications Of Photogrammetry For Retaining Wall Assessment, Renee Oats, Rudiger Escobar-Wolf, Thomas Oommen
Michigan Tech Publications
Retaining walls are critical geotechnical assets and their performance needs to be monitored in accordance to transportation asset management principles. Current practices for retaining wall monitoring consist mostly of qualitative approaches that provide limited engineering information or the methods include traditional geodetic surveying, which may provide high accuracy and reliability, but is costly and time-consuming. This study focuses on evaluating failure modes of a 2.43 m × 2.43 m retaining wall model using three-dimensional (3D) photogrammetry as a cost-effective quantitative alternative for retaining wall monitoring. As a remote sensing technique, photogrammetry integrates images collected from a camera and creates a …
Expanding Understanding Of Optical Variability In Lake Superior With A 4-Year Dataset, Colleen B. Mouw, Audrey B. Ciochetto, Brice Grunert, Angela W. Yu
Expanding Understanding Of Optical Variability In Lake Superior With A 4-Year Dataset, Colleen B. Mouw, Audrey B. Ciochetto, Brice Grunert, Angela W. Yu
Michigan Tech Publications
Lake Superior is one of the largest freshwater lakes on our planet, but few optical observations have been made to allow for the development and validation of visible spectral satellite remote sensing products. The dataset described here focuses on coincidently observing inherent and apparent optical properties along with biogeochemical parameters. Specifically, we observe remote sensing reflectance, absorption, scattering, backscattering, attenuation, chlorophyll concentration, and suspended particulate matter over the ice-free months of 2013-2016. The dataset substantially increases the optical knowledge of the lake. In addition to visible spectral satellite algorithm development, the dataset is valuable for characterizing the variable light field, …
Spatial Variability Of Co < Inf> 2 Uptake In Polygonal Tundra: Assessing Low-Frequency Disturbances In Eddy Covariance Flux Estimates, Norbert Pirk, Jakob Sievers, Jordan Mertes, Frans Jan W. Parmentier, Mikhail Mastepanov, Torben R. Christensen
Spatial Variability Of Co < Inf> 2 Uptake In Polygonal Tundra: Assessing Low-Frequency Disturbances In Eddy Covariance Flux Estimates, Norbert Pirk, Jakob Sievers, Jordan Mertes, Frans Jan W. Parmentier, Mikhail Mastepanov, Torben R. Christensen
Michigan Tech Publications
The large spatial variability in Arctic tundra complicates the representative assessment of CO2 budgets. Accurate measurements of these heterogeneous landscapes are, however, essential to understanding their vulnerability to climate change. We surveyed a polygonal tundra lowland on Svalbard with an unmanned aerial vehicle (UAV) that mapped ice-wedge morphology to complement eddy covariance (EC) flux measurements of CO2. The analysis of spectral distributions showed that conventional EC methods do not accurately capture the turbulent CO2 exchange with a spatially heterogeneous surface that typically features small flux magnitudes. Nonlocal (low-frequency) flux contributions were especially pronounced during snowmelt and introduced a large bias …
New-Generation Nasa Aura Ozone Monitoring Instrument (Omi) Volcanic So2 Dataset: Algorithm Description, Initial Results, And Continuation With The Suomi-Npp Ozone Mapping And Profiler Suite (Omps), Can Li, Nickolay A. Krotkov, Simon Carn, Yan Zhang, Robert J.D. Spurr, Joanna Joiner
New-Generation Nasa Aura Ozone Monitoring Instrument (Omi) Volcanic So2 Dataset: Algorithm Description, Initial Results, And Continuation With The Suomi-Npp Ozone Mapping And Profiler Suite (Omps), Can Li, Nickolay A. Krotkov, Simon Carn, Yan Zhang, Robert J.D. Spurr, Joanna Joiner
Michigan Tech Publications
Since the fall of 2004, the Ozone Monitoring Instrument (OMI) has been providing global monitoring of volcanic SO2 emissions, helping to understand their climate impacts and to mitigate aviation hazards. Here we introduce a new-generation OMI volcanic SO2 dataset based on a principal component analysis (PCA) retrieval technique. To reduce retrieval noise and artifacts as seen in the current operational linear fit (LF) algorithm, the new algorithm, OMSO2VOLCANO, uses characteristic features extracted directly from OMI radiances in the spectral fitting, thereby helping to minimize interferences from various geophysical processes (e.g., O3 absorption) and measurement details (e.g., wavelength shift). To solve …
Arctic Micromonas Uses Protein Pools And Non-Photochemical Quenching To Cope With Temperature Restrictions On Photosystem Ii Protein Turnover, Guangyan Ni, Gabrielle Zimbalatti, Cole D. Murphy, Audrey B. Barnett, Christopher M. Arsenault, Gang Li, Amanda M. Cockshutt, Douglas A. Campbell
Arctic Micromonas Uses Protein Pools And Non-Photochemical Quenching To Cope With Temperature Restrictions On Photosystem Ii Protein Turnover, Guangyan Ni, Gabrielle Zimbalatti, Cole D. Murphy, Audrey B. Barnett, Christopher M. Arsenault, Gang Li, Amanda M. Cockshutt, Douglas A. Campbell
Michigan Tech Publications
Micromonas strains of small prasinophyte green algae are found throughout the world’s oceans, exploiting widely different niches. We grew arctic and temperate strains of Micromonas and compared their susceptibilities to photoinactivation of Photosystem II, their counteracting Photosystem II repair capacities, their Photosystem II content, and their induction and relaxation of non-photochemical quenching. In the arctic strain Micromonas NCMA 2099, the cellular content of active Photosystem II represents only about 50 % of total Photosystem II protein, as a slow rate constant for clearance of PsbA protein limits instantaneous repair. In contrast, the temperate strain NCMA 1646 shows a faster clearance …
Quantitating Active Photosystem Ii Reaction Center Content From Fluorescence Induction Transients, Cole D. Murphy, Guangyan Ni, Gang Li, Audrey Barnett, Kui Xu, Jessica Grant-Burt, Justin D. Liefer, David J. Suggett, Douglas A. Campbell
Quantitating Active Photosystem Ii Reaction Center Content From Fluorescence Induction Transients, Cole D. Murphy, Guangyan Ni, Gang Li, Audrey Barnett, Kui Xu, Jessica Grant-Burt, Justin D. Liefer, David J. Suggett, Douglas A. Campbell
Michigan Tech Publications
Photosystem II (PSII) is a pigment-protein complex that photochemically extracts electrons from water, generating the reductant that supports biological productivity in all biomes. Estimating the content of active PSII reaction centers in a liquid sample is a key input for estimating aquatic photosynthesis rates, as well as for analyzing phytoplankton stress responses. Established procedures for PSII content quantification based on oxygen evolution are slow, imprecise and require dense cell suspensions, and are thus inapplicable to many laboratory or field studies. A new approach uses baseline chlorophyll fluorescence emission divided by the effective absorbance cross section for PSII photochemistry, with both …
Surface Ozone And Its Precursors At Summit, Greenland: Comparison Between Observations And Model Simulations, Yaoxian Huang, Shiliang Wu, Louisa J. Kramer, Detlev Helmig, Richard E. Honrath
Surface Ozone And Its Precursors At Summit, Greenland: Comparison Between Observations And Model Simulations, Yaoxian Huang, Shiliang Wu, Louisa J. Kramer, Detlev Helmig, Richard E. Honrath
Michigan Tech Publications
Recent studies have shown significant challenges for atmospheric models to simulate tropospheric ozone (O3/and its precursors in the Arctic. In this study, ground-based data were combined with a global 3-D chemical transport model (GEOS-Chem) to examine the abundance and seasonal variations of O3 and its precursors at Summit, Greenland (72.34° N, 38.29° W; 3212 ma.s.l.). Model simulations for atmospheric nitrogen oxides (NOx/, peroxyacetyl nitrate (PAN), ethane (C2H6/, propane (C3H8/, carbon monoxide (CO), and O3 for the period July 2008-June 2010 were compared with observations. The model performed well in simulating certain species (such as CO and C3H8/, but some significant …