A single-force model for the 1975 Kalapana, Hawaii, Earthquake

A single force mechanism is investigated as the source of long-period seismic radiation from the 1975 Kalapana, Hawaii, earthquake (M_S = 7.1). The observed Love wave radiation pattern determined from the spectra of World-Wide Standard Seismograph Network and High Gain Long Period records at 100 s is two-lobed with azimuth, consistent with a near-horizontal single force acting opposite (strike ∼330°) to the observed displacement direction of the earthquake; this pattern is inconsistent with the expected double-couple pattern. Assuming a form of the force time history of a one-cycle sinusoid, the total duration of the event estimated from Rayleigh waves at two International Deployment of Accelerometers stations is approximately 180 s. The peak amplitude f_o of the time function is 1 × 10^(15) N from amplitudes of Love and Rayleigh waves. The interpretation is that the bulk of the seismic radiation was produced by large-scale slumping of a large area of the south flank of Kilauea volcano. The single force is a crude representation of the effect on the earth of the motion of a partially decoupled large slide mass. Using the mass estimated from the tsunami generation area (∼ 10^(15)–10^(16) kg), the peak acceleration of the slide block (0.1–1 m s^(−2)) inferred from the seismic force is comparable with the acceleration due to gravity on a gently inclined plane. The slump model for the Kalapana earthquake is also more qualitatively consistent with the large horizontal deformation (8 m on land) and tsunami associated with the earthquake, which are difficult to explain with the conventional double-couple source model. The single-force source has been used previously to model the long-period seismic waves from the landslide accompanying the eruption of Mount St. Helens volcano, and may explain other anomalous seismic events as being due to massive slumping of sediments or unconsolidated material and not to elastic dislocation

Depth estimates of large earthquakes on the Island of Hawaii since 1940

Although hypocenters of earthquakes on the island of Hawaii are now routinely assigned to within 5 km, depth was a poorly determined parameter until the early 1960's. However, the 1950–1960 period was very active both in volcanic eruptions and large earthquakes. Source depths for the 12 largest Hawaiian earthquakes (magnitude 6 or greater) since 1940 are estimated from the ratios of body and surface wave amplitudes recorded at Pasadena, California. Excitation functions for Rayleigh waves are calculated as a function of source depth for the two dominant periods in the Pasadena records, 8s and 20s. Theoretical body wave amplitudes are determined from synthetic seismograms. Calculated ratios are very sensitive to source depth; for example, amplitudes of 8-s Rayleigh waves diminish by a factor of 300 between depths of 10 km and 50 km. This is a much larger effect than the fault geometry, which we estimate to be a factor of 4 between representative focal mechanisms. Estimated depths for post-1960 earthquakes agree fairly well with the instrumental depths. In general, large earthquakes near the volcanic flanks and fault systems are shallow (≤20 km). Two earthquakes of magnitude 6 occurred under the volcanoes Mauna Loa (in 1950) and Kilauea (in 1951); they preceded major eruptions by 3 days and 14 months, respectively, and had the largest depth estimates at 40–55 km and 35–50 km. MS values assigned from global amplitudes are compared with those assigned from Pasadena amplitudes alone, for 70 events in 1973–1974 with 5.1≤ M_S ≤ 6.0. The global values are only slightly larger (0.05 magnitude units) than the Pasadena values, indicating that Pasadena amplitudes are on the average representative of the event magnitude

Reply [to “Comment on ‘A single-force model for the 1975 Kalapana, Hawaii, earthquake’ by Holly K. Eissler and Hiroo Kanamori”]

We showed that the long-period seismic radiation from the November 29, 1975, Kalapana Hawaii earthquake, which involved seaward displacement of the south flank of Kilauea volcano, was best explained by invoking a near-horizontal single force as the kinematic source of the earthquake [Eissler and Kanamori, 1987]. In particular, the azimuthal dependence of 100-s Love surface waves is difficult to explain by a conventional double-couple source. The unusual Love wave pattern was noted by Ando [1979] but not explained until our suggestion of the single-force source model

Bacterial Active Community Cycling in Response to Solar Radiation and Their Influence on Nutrient Changes in a High-Altitude Wetland

Indexación: Web of Science; Scopus.Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1). Diversity increased at noon, when the highest irradiances were measured (3.3-3.9 H', 1125 W m(-2)) compared to morning and afternoon (0.6-2.8 H'). This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (< 0.5%) in the pyrolibraries. A potential increase in the activity of Cyanobacteria and other phototrophic groups, e.g., Rhodobacterales, was observed and associated with UVR, suggesting the presence of photo activated repair mechanisms to resist high levels of solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite, and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in situ, but both functional groups (Nitrosomona and Nitrospira) appeared mainly in pyrolibraries generated from dark incubations. In total, our results reveal that both the structure and the diversity of the active bacteria community was extremely dynamic through the day, and showed marked shifts in composition that influenced nutrient recycling, highlighting how abiotic variation affects potential ecosystem functioning.http://journal.frontiersin.org/article/10.3389/fmicb.2016.01823/ful

Bacterial Active Community Cycling in Response to Solar Radiation and Their Influence on Nutrient Changes in a High-Altitude Wetland

This research was supported by funds granted by Comisión Nacional de Investigación Científica y Tecnológica (CONICYT, Chile) FONDECYT grants N° 1110824, 1140179, 11110190, 1100358, 1110953, and 1140356; CONICYT-PIA FB0001

Spontaneous expectoration of pulmonary metastases in a child with osteogenic sarcoma

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148355/1/pbc27611.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148355/2/pbc27611_am.pd

The defiant ones: A common form of character pathology in children

The paper focuses on a common kind of childhood psychopathology that is often misdiagnosed as incorrigibly delinquent and psychopathic. Many children with a chronic history of defiance and antisocial behavior are struggling with intense internal conflicts. The etiology and dynamics of these youngsters, as well as the treatment implications and techniques, are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44354/1/10615_2004_Article_BF00755910.pd

The management aspect of psychotherapy with aggressive children

Psychotherapy with an aggressive child may require the imposition of rather firm limitations over aspects of the patient's aggressive behavior. The nature of this management strategy is determined by the individual child's psychopathology. The management aspects of the psychotherapy with two aggressive boys are illustrated in detail. In one case, stringent limitations were imposed when it was discovered that the boy's behavior was regressive and represented an effort to sadistically control people in his environment. In the other case, the behavior was initially left almost unchallenged; this boy's aggressive and delinquent behavior reflected an effort to achieve a sense of order in an inconsistent external and potentially chaotic internal environment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43969/1/10578_2005_Article_BF01463450.pd