Recent unrest (2002–2015) imaged by space geodesy at the highest risk Chilean volcanoes: Villarrica, Llaima, and Calbuco (Southern Andes)

Villarrica, Llaima, and Calbuco volcanoes are the most active and dangerous volcanoes in the Southern Andes, and we use Interferometric Synthetic Aperture Radar (InSAR) observations from multiple satellites (ERS-2, ENVISAT, ALOS, RADARSAT-2, COSMO-SkyMed, TerraSAR-X, Sentinel-1A and ALOS-2) to constrain ground deformation that spans episodes of unrest and eruption at all three volcanoes between 2002 and 2015. We find episodes of ground deformation at each volcano, which we invert using analytic elastic half space models to make some of the first geophysical inferences about the source depths of potential magma chambers. At Llaima, we interpret that the VEI 2 April 3, 2009 eruption was preceded by 6–15 cm of precursory ground uplift one month before from a source 5 km below the surface on the western side of the edifice. The VEI 2 March 3, 2015 Villarrica eruption was followed by a short lived uplift of 5 cm in the SE part of the volcano from a source depth of 6 km. The VEI 4 April 22–23, 2015 Calbuco eruption produced 12 cm of coeruptive subsidence from a source depth 8–11 km and offset 2 km S from the summit. Importantly, we do not find clear evidence that the January 1, 2008, the March 3, 2015 and April 22, 2015 eruptions at Llaima, Villarrica and Calbuco volcanoes were preceded by either transient or continuous ground uplift. There are several possible explanations for the lack of precursory deformation at each volcano – it is possible that any precursory deformation occurred only hours before the eruption (e.g., at Calbuco), pre-eruptive inflation was canceled by co-eruptive subsidence (as we inferred happened during the April 2009 Llaima eruption), the pre-eruptive deformation was too small to be detectable in areas with persistent topography correlated phase delays, pressurized source are deep, or that open-vent volcanoes like Villarrica and Llaima do not pressurize. At all three volcanoes, X and C band interferograms decorrelate in a few weeks due to vegetation, snow and ice, and have persistent atmospheric phase delays that we find cannot be reliably removed with available global weather models. The low number of SAR acquisitions therefore makes it challenging to reliably measure unaliased deformation. We recommend a multi-satellite observing strategy with short repeat periods, frequently acquired high-resolution digital elevation models, and with acquisitions during every satellite overflight that may improve the temporal resolution of measurements

Recent unrest (2002–2015) imaged by space geodesy at the highest risk Chilean volcanoes: Villarrica, Llaima, and Calbuco (Southern Andes)

Villarrica, Llaima, and Calbuco volcanoes are the most active and dangerous volcanoes in the Southern Andes, and we use Interferometric Synthetic Aperture Radar (InSAR) observations from multiple satellites (ERS-2, ENVISAT, ALOS, RADARSAT-2, COSMO-SkyMed, TerraSAR-X, Sentinel-1A and ALOS-2) to constrain ground deformation that spans episodes of unrest and eruption at all three volcanoes between 2002 and 2015. We find episodes of ground deformation at each volcano, which we invert using analytic elastic half space models to make some of the first geophysical inferences about the source depths of potential magma chambers. At Llaima, we interpret that the VEI 2 April 3, 2009 eruption was preceded by 6–15 cm of precursory ground uplift one month before from a source 5 km below the surface on the western side of the edifice. The VEI 2 March 3, 2015 Villarrica eruption was followed by a short lived uplift of 5 cm in the SE part of the volcano from a source depth of 6 km. The VEI 4 April 22–23, 2015 Calbuco eruption produced 12 cm of coeruptive subsidence from a source depth 8–11 km and offset 2 km S from the summit. Importantly, we do not find clear evidence that the January 1, 2008, the March 3, 2015 and April 22, 2015 eruptions at Llaima, Villarrica and Calbuco volcanoes were preceded by either transient or continuous ground uplift. There are several possible explanations for the lack of precursory deformation at each volcano – it is possible that any precursory deformation occurred only hours before the eruption (e.g., at Calbuco), pre-eruptive inflation was canceled by co-eruptive subsidence (as we inferred happened during the April 2009 Llaima eruption), the pre-eruptive deformation was too small to be detectable in areas with persistent topography correlated phase delays, pressurized source are deep, or that open-vent volcanoes like Villarrica and Llaima do not pressurize. At all three volcanoes, X and C band interferograms decorrelate in a few weeks due to vegetation, snow and ice, and have persistent atmospheric phase delays that we find cannot be reliably removed with available global weather models. The low number of SAR acquisitions therefore makes it challenging to reliably measure unaliased deformation. We recommend a multi-satellite observing strategy with short repeat periods, frequently acquired high-resolution digital elevation models, and with acquisitions during every satellite overflight that may improve the temporal resolution of measurements

Electroweak Constraints on Warped Geometry in Five Dimensions and Beyond

Here we consider the tree level corrections to electroweak (EW) observables from standard model (SM) particles propagating in generic warped extra dimensions. The scale of these corrections is found to be dominated by three parameters, the Kaluza-Klein (KK) mass scale, the relative coupling of the KK gauge fields to the Higgs and the relative coupling of the KK gauge fields to fermion zero modes. It is found that 5D spaces that resolve the hierarchy problem through warping typically have large gauge-Higgs coupling. It is also found in $D>5$ where the additional dimensions are warped the relative gauge-Higgs coupling scales as a function of the warp factor. If the warp factor of the additional spaces is contracting towards the IR brane, both the relative gauge-Higgs coupling and resulting EW corrections will be large. Conversely EW constraints could be reduced by finding a space where the additional dimension's warp factor is increasing towards the IR brane. We demonstrate that the Klebanov Strassler solution belongs to the former of these possibilities.Comment: 18 pages, 3 figures (references added) version to appear in JHE

Flavor Phenomenology in General 5D Warped Spaces

We have considered a general 5D warped model with SM fields propagating in the bulk and computed explicit expressions for oblique and non-oblique electroweak observables as well as for flavor and CP violating effective four-fermion operators. We have compared the resulting lower bounds on the Kaluza-Klein (KK) scale in the RS model and a recently proposed model with a metric modified towards the IR brane, which is consistent with oblique parameters without the need for a custodial symmetry. We have randomly generated 40,000 sets of O(1) 5D Yukawa couplings and made a fit of the quark masses and CKM matrix elements in both models. This method allows to identify the percentage of points consistent with a given KK mass, which in turn provides us with a measure for the required fine-tuning. Comparison with current experimental data on Rb, FCNC and CP violating operators exhibits an improved behavior of our model with respect to the RS model. In particular, allowing 10% fine-tuning the combined results point towards upper bounds on the KK gauge boson masses around 3.3 TeV in our model as compared with 13 TeV in the RS model. One reason for this improvement is that fermions in our model are shifted, with respect to fermions in the RS model, towards the UV brane thus decreasing the strength of the modifications of electroweak observables.Comment: 28 pages, 7 figures, 4 table

Naturalness bounds in extensions of the MSSM without a light Higgs boson

Adopting a bottom-up point of view, we make a comparative study of the simplest extensions of the MSSM with extra tree level contributions to the lightest Higgs boson mass. We show to what extent a relatively heavy Higgs boson, up to 200-350 GeV, can be compatible with data and naturalness. The price to pay is that the theory undergoes some change of regime at a relatively low scale. Bounds on these models come from electroweak precision tests and naturalness, which often requires the scale at which the soft terms are generated to be relatively low.Comment: 18 pages, 5 figures. v2: minor revision, added references. v3,v4: some numerical correction

Reducing Constraints in a Higher Dimensional Extension of the Randall and Sundrum Model

In order to investigate the phenomenological implications of warped spaces in more than five dimensions, we consider a $4+1+\delta$ dimensional extension to the Randall and Sundrum model in which the space is warped with respect to a single direction by the presence of an anisotropic bulk cosmological constant. The Einstein equations are solved, giving rise to a range of possible spaces in which the $\delta$ additional spaces are warped. Here we consider models in which the gauge fields are free to propagate into such spaces. After carrying out the Kaluza Klein (KK) decomposition of such fields it is found that the KK mass spectrum changes significantly depending on how the $\delta$ additional dimensions are warped. We proceed to compute the lower bound on the KK mass scale from electroweak observables for models with a bulk $SU(2)\times U(1)$ gauge symmetry and models with a bulk $SU(2)_R\times SU(2)_L\times U(1)$ gauge symmetry. It is found that in both cases the most favourable bounds are approximately $M_{KK}\gtrsim 2$ TeV, corresponding to a mass of the first gauge boson excitation of about 4-6 TeV. Hence additional warped dimensions offer a new way of reducing the constraints on the KK scale.Comment: 27 pages, 15 figures, v3: Additional comments in sections 1, 2 and 4. New appendix added. Five additional figures. References adde

Suppressing Electroweak Precision Observables in 5D Warped Models

We elaborate on a recently proposed mechanism to suppress large contributions to the electroweak precision observables in five dimensional (5D) warped models, without the need for an extended 5D gauge sector. The main ingredient is a modification of the AdS metric in the vicinity of the infrared (IR) brane corresponding to a strong deviation from conformality in the IR of the 4D holographic dual. We compute the general low energy effective theory of the 5D warped Standard Model, emphasizing additional IR contributions to the wave function renormalization of the light Higgs mode. We also derive expressions for the S and T parameters as a function of a generic 5D metric and zero-mode wave functions. We give an approximate formula for the mass of the radion that works even for strong deviation from the AdS background. We proceed to work out the details of an explicit model and derive bounds for the first KK masses of the various bulk fields. The radion is the lightest new particle although its mass is already at about 1/3 of the mass of the lightest resonances, the KK states of the gauge bosons. We examine carefully various issues that can arise for extreme choices of parameters such as the possible reintroduction of the hierarchy problem, the onset of nonperturbative physics due to strong IR curvature or the creation of new hierarchies near the Planck scale. We conclude that a KK scale of 1 TeV is compatible with all these constraints.Comment: 44 pages, 11 figures, references adde

Changes in the Activities, Functions, and Roles of Public Health Educators

Accounts of early activities of public health educators, statements of the American Public Health Association on the qualifications and functions of these educators, and studies concerned with their responsibilities, functions, work, or roles are reviewed. These point up the three major foci in public health education over time in the U.S., viz, dissemination of information, community organization, and health behavior and program planning. Functions of public health educators in emerging settings for practice are presented and the implications of this movement (i.e., movement of health educators into non-traditional settings) for the public health education profession are discussedPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66927/2/10.1177_109019817600400304.pd