Maars to calderas. End-members on a spectrum of explosive volcanic depressions

We discuss maar-diatremes and calderas as end-members on a spectrum of negative volcanic landforms (depressions) produced by explosive eruptions (note—we focus on calderas formed during explosive eruptions, recognizing that some caldera types are not related to such activity). The former are dominated by ejection of material during numerous discrete phreatomagmatic explosions, brecciation, and subsidence of diatreme fill, while the latter are dominated by subsidence over a partly evacuated magma chamber during sustained, magmatic volatile-driven discharge. Many examples share characteristics of both, including landforms that are identified as maars but preserve deposits from non-phreatomagmatic explosive activity, and ambiguous structures that appear to be coalesced maars but that also produced sustained explosive eruptions with likely magma reservoir subsidence. A convergence of research directions on issues related to magma-water interaction and shallow reservoir mechanics is an important avenue toward developing a unified picture of the maar-diatreme-caldera spectrum

Corrigendum. Maars to calderas: end-members on a spectrum of explosive volcanic depressions

A corrigendum on Maars to calderas: end-members on a spectrum of explosive volcanic depressions by Palladino, D. M., Valentine, G. A., Sottili, G., and Taddeucci, J. (2015). Front. Earth Sci. 3:36. doi: 10.3389/feart.2015.00036 Reason for Corrigendum: In the original article (Palladino et al., 2015), there was an error in Figure 1. The vertical axis of the qualitative plot reported erroneously “ratio of juvenile to lithic materials in deposits outside of depression”. The correct wording is as follows: “ratio of juvenile to total (i.e., juvenile+lithic) materials in deposits outside of depression”. In fact, as it was reported correctly in the text, the amount of juvenilematerial (i.e., scoria or pumice) deposited ouside the different types of explosive volcanic depressions increases from zero (i.e., no juvenile, all lithic products), as is the case of hydrothermal (phreatic) explosion craters, to become largely dominant over the lithic component in the case of ash flow deposits associated with large overpressure collapse calderas. The corrected Figure 1 appears below. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way

Book Review of Hope\u27s Boy: A Memoir & The Women Who Raised Me: A Memoir

The preparation of preservice administrators and teachers poses daunting challenges for the academy. Federal mandates associated with the No Child Left Behind Act (NCLB) and The Individuals with Disabilities Education Act (IDEA), and the pressure on school districts to produce high-perform- ing students despite inadequate financial resources, have shifted public ed- ucation\u27s focus towards youth\u27s academic proficiency. The linear focus has trumped the nurturing role school personnel could and should fulfill in ad- dition to scholastic achievement. Foster care youth, in particular, validate the need for educational leaders who can nurture the overall emotional well-being of vulnerable children. The blase philosophy that public education should provide equal treatment of all children, a notion that a balanced playing field ensures success for children identified as at-risk, is not viable. In reality, children in foster care arrive at the schoolhouse door often harboring emotional scars associated with their abuse and neglect. Their plight poses a twofold question: Should school administrators provide differentiated leadership on behalf of youth in foster care? If so, what should constitute it

Neutrino telescopes and high-energy cosmic neutrinos

In this review paper, we present the main aspects of high-energy cosmic neutrino astrophysics. We begin by describing the generic expectations for cosmic neutrinos, including the effects of propagation from their sources to the detectors. Then we introduce the operating principles of current neutrino telescopes, and examine the main features (topologies) of the observable events. After a discussion of the main background processes, due to the concomitant presence of secondary particles produced in the terrestrial atmosphere by cosmic rays, we summarize the current status of the observations with astrophysical relevance that have been greatly contributed by IceCube detector. Then, we examine various interpretations of these findings, trying to assess the best candidate sources of cosmic neutrinos. We conclude with a brief perspective on how the field could evolve within a few years

Cosmic Microwave Background Temperature at Galaxy Clusters

We have deduced the cosmic microwave background (CMB) temperature in the Coma cluster (A1656, $z=0.0231$), and in A2163 ($z=0.203$) from spectral measurements of the Sunyaev-Zel'dovich (SZ) effect over four passbands at radio and microwave frequencies. The resulting temperatures at these redshifts are $T_{Coma} = 2.789^{+0.080}_{-0.065}$ K and $T_{A2163} = 3.377^{+0.101}_{-0.102}$ K, respectively. These values confirm the expected relation $T(z)=T_{0}(1+z)$, where $T_{0}= 2.725 \pm 0.002$ K is the value measured by the COBE/FIRAS experiment. Alternative scaling relations that are conjectured in non-standard cosmologies can be constrained by the data; for example, if $T(z) = T_{0}(1+z)^{1-a}$ or $T(z)=T_{0}[1+(1+d)z]$, then $a=-0.16^{+0.34}_{-0.32}$ and $d = 0.17 \pm 0.36$ (at 95% confidence). We briefly discuss future prospects for more precise SZ measurements of $T(z)$ at higher redshifts.Comment: 13 pages, 1 figure, ApJL accepted for publicatio