Geomorphic and thermochronologic signatures of active tectonics in the central Nepalese Himalaya

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2005.Includes bibliographical references.The central Nepalese Himalaya are characterized by a sharp transition in physiography that does not correlate with previously mapped faults. Rates of rock uplift, erosion, and exhumation for rocks surrounding this physiographic transition are investigated using digital topographic data, ⁴⁰Ar/³⁹Ar thermochronology, cosmogenic radionuclides, and thermal modeling, to determine whether this break in landscape morphology reflects active tectonic displacements at the foot of the Himalaya. The goals of the thesis are 1) to understand the degree to which landscape morphology can be used to delineate breaks in rock uplift in active orogens; 2) to characterize the neotectonics of central Nepal using data representing varied temporal and spatial scales of inquiry; and 3) to move closer to understanding the dynamic interactions among climate, erosion and tectonics in a field setting. Analysis of digital topographic data from Nepal and other tectonically active settings demonstrates how breaks in the simple scaling characterizing river systems can be used to identify tectonic boundaries.(cont.) Limitations to these methods are illustrated by way of an example from the Eastern Central Range of Taiwan, but changes in landscape morphology become the foundation upon which further investigations are built for central Nepal. These investigations include data from detrital ⁴⁰Ar/³⁹Ar thermochronology to characterize changes in exhumation rates at million-year timescales; cosmogenic ¹⁰Be to characterize changes in erosion rates at millennial timescales; and simple thermal modeling to evaluate a range of alternative tectonic geometries for central Nepal. The data point to the existence of a tectonically significant, thrust- sense shear zone at the base of the high Himalaya in central Nepal, nearly 100 km north of the active thrust front. The existence of this fault zone in a location where the Indian summer monsoon is concentrated is consistent with the predictions of numerical and analytical models of orogenic growth, which suggest a direct feedback between focused erosion and tectonic displacements in active orogens.(cont.) Future work is warranted to evaluate the persistence of climatic and tectonic signals over a variety of time and space scales in central Nepal, and to determine whether correlations between climate and tectonics exist in other field settings.by Cameron W. Wobus.Ph.D

Internet of Things for Sustainability: Perspectives in Privacy, Cybersecurity, and Future Trends

In the sustainability IoT, the cybersecurity risks to things, sensors, and monitoring systems are distinct from the conventional networking systems in many aspects. The interaction of sustainability IoT with the physical world phenomena (e.g., weather, climate, water, and oceans) is mostly not found in the modern information technology systems. Accordingly, actuation, the ability of these devices to make changes in real world based on sensing and monitoring, requires special consideration in terms of privacy and security. Moreover, the energy efficiency, safety, power, performance requirements of these device distinguish them from conventional computers systems. In this chapter, the cybersecurity approaches towards sustainability IoT are discussed in detail. The sustainability IoT risk categorization, risk mitigation goals, and implementation aspects are analyzed. The openness paradox and data dichotomy between privacy and sharing is analyzed. Accordingly, the IoT technology and security standard developments activities are highlighted. The perspectives on opportunities and challenges in IoT for sustainability are given. Finally, the chapter concludes with a discussion of sustainability IoT cybersecurity case studies

Virology under the microscope—a call for rational discourse

Viruses have brought humanity many challenges: respiratory infection, cancer, neurological impairment and immunosuppression to name a few. Virology research over the last 60+ years has responded to reduce this disease burden with vaccines and antivirals. Despite this long history, the COVID-19 pandemic has brought unprecedented attention to the field of virology. Some of this attention is focused on concern about the safe conduct of research with human pathogens. A small but vocal group of individuals has seized upon these concerns – conflating legitimate questions about safely conducting virus-related research with uncertainties over the origins of SARS-CoV-2. The result has fueled public confusion and, in many instances, ill-informed condemnation of virology. With this article, we seek to promote a return to rational discourse. We explain the use of gain-of-function approaches in science, discuss the possible origins of SARS-CoV-2 and outline current regulatory structures that provide oversight for virological research in the United States. By offering our expertise, we – a broad group of working virologists – seek to aid policy makers in navigating these controversial issues. Balanced, evidence-based discourse is essential to addressing public concern while maintaining and expanding much-needed research in virology

Quantifying and valuing potential climate change impacts on coral reefs in the United States: comparison of two scenarios.

The biological and economic values of coral reefs are highly vulnerable to increasing atmospheric and ocean carbon dioxide concentrations. We applied the COMBO simulation model (COral Mortality and Bleaching Output) to three major U.S. locations for shallow water reefs: South Florida, Puerto Rico, and Hawaii. We compared estimates of future coral cover from 2000 to 2100 for a "business as usual" (BAU) greenhouse gas (GHG) emissions scenario with a GHG mitigation policy scenario involving full international participation in reducing GHG emissions. We also calculated the economic value of changes in coral cover using a benefit transfer approach based on published studies of consumers' recreational values for snorkeling and diving on coral reefs as well as existence values for coral reefs. Our results suggest that a reduced emissions scenario would provide a large benefit to shallow water reefs in Hawaii by delaying or avoiding potential future bleaching events. For Hawaii, reducing emissions is projected to result in an estimated "avoided loss" from 2000 to 2100 of approximately $10.6 billion in recreational use values compared to a BAU scenario. However, reducing emissions is projected to provide only a minor economic benefit in Puerto Rico and South Florida, where sea-surface temperatures are already close to bleaching thresholds and coral cover is projected to drop well below 5% cover under both scenarios by 2050, and below 1% cover under both scenarios by 2100

Economic values (with 95% confidence interval) for BAU and reduced emission scenarios for Hawaii.

<p>Economic values (with 95% confidence interval) for BAU and reduced emission scenarios for Hawaii.</p

Review of estimated snorkeling and diving recreational values.

<p>^a . Average of values for residents, visiting snorkelers, and visiting divers.</p

Likely effects of uncertainty factors on ecological and economic values of coral reefs, compared to model projections for BAU and policy scenarios^a.

<p>^a Factors judged likely to have a substantially greater impact than others are indicated by bold type.</p

Economic values (with 95% confidence interval) for BAU and reduced emission scenarios for Puerto Rico.

<p>Economic values (with 95% confidence interval) for BAU and reduced emission scenarios for Puerto Rico.</p

CO₂ concentrations (ppm) for alternative emissions scenarios used in the model, for the years 2000–2100.

<p>CO₂ concentrations (ppm) for alternative emissions scenarios used in the model, for the years 2000–2100.</p