Community preparedness for lava flows from Mauna Loa and Hualālai volcanoes,Kona, Hawai‘i

Lava flows from Mauna Loa and Huallai volcanoes are a major volcanic hazard that could impact the western portion of the island of Hawaii (e.g., Kona). The most recent eruptions of these two volcanoes to affect Kona occurred in a.d. 1950 and ca. 1800, respectively. In contrast, in eastern Hawaii, eruptions of neighboring Klauea volcano have occurred frequently since 1955, and therefore have been the focus for hazard mitigation. Official preparedness and response measures are therefore modeled on typical eruptions of Klauea.The combinations of short-lived precursory activity (e.g., volcanic tremor) at Mauna Loa, the potential for fast-moving lava flows, and the proximity of Kona communities to potential vents represent significant emergency management concerns in Kona. Less is known about past eruptions of Huallai, but similar concerns exist. Future lava flows present an increased threat to personal safety because of the short times that may be available for responding.Mitigation must address not only the specific characteristics of volcanic hazards in Kona, but also the manner in which the hazards relate to the communities likely to be affected. This paper describes the first steps in developing effective mitigation plans: measuring the current state of peoples knowledge of eruption parameters and the implications for their safety. We present results of a questionnaire survey administered to 462 high school students and adults in Kona. The rationale for this study was the long lapsed time since the last Kona eruption, and the high population growth and expansion of infrastructure over this time interval. Anticipated future growth in social and economic infrastructure in this area provides additional justification for this work.The residents of Kona have received little or no specific information about how to react to future volcanic eruptions or warnings, and short-term preparedness levels are low. Respondents appear uncertain about how to respond to threatening lava flows and overestimate the minimum time available to react, suggesting that personal risk levels are unnecessarily high. A successful volcanic warning plan in Kona must be tailored to meet the unique situation there.     

The role of wind direction in eolian transport on a narrow sandy beach

Comparison of eolian transport during five high-velocity wind events over a 29 day period on a narrow estuarine beach in Delaware Bay, New Jersey, USA, reveals the temporal variability of transport, due to changes in direction of wind approach. Mean wind speed measured 6 m above the dune crest for the five events ranged from 8·5 to 15·9 ms^?1. Mean wind direction was oblique to the shoreline (63° from shore-normal) during one event but was within 14° of shore-normal during the other events. Eolian transport is greatest during low tide and rising tide, when the beach source area is widest and when drying of surface sediments occurs. The quantity of sediment caught in a vertical trap for the five events varied from a total of 0·07 to 113·73 kgm^?1. Differences in temperature, relative humidity and moisture and salt content of surficial sediments were slight. Mean grain sizes ranged from 0·33 to 0·58 mm, causing slight differences in threshold shear velocity, but shear velocities exceeded the threshold required for transport during all events. Beach width, measured normal to the shoreline, varied from 15·5 to 18·0 m; beach slope differed by 0·5°. The oblique wind during one event created a source width nearly double the width during other days. Beach slope, measured in the direction of the wind, was less than half as steep as the slope measured normal to the shoreline. The amount of sand trapped during the oblique wind was over 20 times greater than any other event, even those with higher shear velocities. The ability of the beach surface to supply grains to the air stream is limited on narrow beaches, but increased source width, due to oblique wind approach, can partially overcome limitations of surface conditions on the beach.     

System identification of a concrete arch dam and calibration of its finite element model

A magnitude 4.3 earthquake occurred near Pacoima Dam on 13 January 2001. An accelerometer array that had been upgraded after the Northridge earthquake recorded the motion with 17 channels on the dam and the dam–foundation interface. Using this data, properties of the first two modes are found from a system identification study. Modal properties are also determined from a forced vibration experiment performed in 2002 and indicate a significantly stiffer system than is estimated from the 2001 earthquake records. The 2001 earthquake, although small, must have induced temporary nonlinearity. This has implications for structural health monitoring. The source of the nonlinear behaviour is believed to be loss of stiffness in the foundation rock. A finite element model of Pacoima Dam is constructed and calibrated to match modal properties determined from the system identification study. A dynamic simulation of the 2001 earthquake response produces computed motions that agree fairly well with the recorded ones. Copyright © 2006 John Wiley & Sons, Ltd.     

Nordostalpine Seehöhenmittel der Niederschlagsmenge (1851–1950)

Zusammenfassung Aus 320 Niederschlagsstationen der Periode 1891 bis 1930 werden für 50 m-Stufen Seehöhenmittel der Niederschlagsmenge für die Monate und für das Jahr abgeleitet und auf die Periode 1851 bis 1950 umgerechnet mitgeteilt. Die klimatische Besonderheit einer sekundären Maispitze in den monatlichen Niederschlagsmengen, die sich in der 100jährigen Wiener Reihe als Häufigkeitsmaximum maximaler Monatswerte, der Niederschlagsmenge zeigt, wird als Besonderheit des pannonischen Klimas erkannt und ihre auffällige Auswirkung in den abgeleiteten Seehöhenmitteln als Effekt örtlicher Mai-Gewitter und Starkregen klargestellt. Vergleiche der Niederschlagskurven verschiedener Bergstationen erläutern die Uneinheitlichkeit des alpinen Niederschlagsregimes als Folge der Funktion der Alpen als mehrfacher Klimascheide und die Notwendigkeit, von einem einheitlichen regionalen Mittelwert für die ganzen Alpen abzusehen. Als Folge dieser Tatsache werden regionale Mittelwerte als Grundlagen für Anomaliendarstellungen des alpinen Niederschlagsregimes abgelehnt und die Gründe hierfür an einem Beispiel erläutert.

---

Summary On the basis of measurements at 320 stations of the period 1891–1930 monthly and annual averages of precipitation are calculated for 50 m-intervals of altitude and reduced to the period 1851–1950. The climatic peculiarity of a secondary may-maximum in the monthly amounts of rainfall resulting from the 100 year-series at Vienna as a frequency maximum of the highest monthly values of precipitation was found to be characteristic for the Pannonian climate. Its obvious effect as shown by the averages derived for different altitudes is accounted for by the local may-thunderstorms and downpours. By comparison of the precipitation curves of different mountain stations it becomes clear that there exists no uniform Alpine precipitation regime on account of the Apls functioning as climatic septum. Hence the necessity follows to renounce a uniform regional mean value for the Alps. Therefore, it is not allowed to use regional mean values as a basis for representing the anomalies of the Alpine precipitation regime, what is shown by an example.

---

Résumé On évalue des précipitations mensuelles et annuelles moyennes pour les niveaux de 50 en 50 m à partir des mesures de 320 stations de la période 1891–1930, réduite à la période 1851–1950. Le maximum secondaire du mois de mai (ou apparaît dans la série, centenaire de Vienne la fréquence la plus élevée des maxima mensuels) est considéré comme une particularité du climat de la Pannonie; il est dû aux orages locaux de mai et à des averses torrentielles. La comparaison des courbes de précipitations de différentes stations de montagne illustre le caractère hétérogère du régime pluvial alpin, conséquence des particularités géographiques de la grande chaîne comme barrière climatique; elle montre aussi l'impossibilité d'établir une valeur moyenne caractéristique de l'ensemble du domaine alpin. L'auteur renonce de ce fait à faire appel à des moyennes régionales pour l'étude des anomalies du régime pluvial alpin et en donne les motifs par un exemple.

---

---

Mit 2 Textabbildungen.     

The Influence of Oxalate on Fe-Catalyzed S(IV) Oxidation by Oxygen in Aqueous Solution

This study demonstrates that oxalate has a strong inhibiting effect onFe-catalyzed S(IV) oxidation by oxygen in aqueous solution. While thepseudo-first order rate constant of S(IV) oxidation was determined to be1.6 × 10³ M^-1 s^-1 in experimentswithout oxalate, the oxidation of S(IV) was totally inhibited at a molarconcentration ratio of iron:oxalate = 1:5 at an oxalate concentration of 4M. Under these conditions, the Fe(II)/Fe(III) ratio remained nearlyconstant during the observed reaction time. The determined rate constants wereindependent of the initial oxidation state of iron. However, with increasingconcentrations of oxalate, a longer induction period is observed forexperiments with iron initially in the Fe(II) oxidation state.     

Impact of different convective cloud schemes on the simulation of the tropical seasonal cycle in a coupled ocean–atmosphere model

The simulation of the mean seasonal cycle of sea surface temperature (SST) remains a challenge for coupled ocean–atmosphere general circulation models (OAGCMs). Here we investigate how the numerical representation of clouds and convection affects the simulation of the seasonal variations of tropical SST. For this purpose, we compare simulations performed with two versions of the same OAGCM differing only by their convection and cloud schemes. Most of the atmospheric temperature and precipitation differences between the two simulations reflect differences found in atmosphere-alone simulations. They affect the ocean interior down to 1,000 m. Substantial differences are found between the two coupled simulations in the seasonal march of the Intertropical Convergence Zone in the eastern part of the Pacific and Atlantic basins, where the equatorial upwelling develops. The results confirm that the distribution of atmospheric convection between ocean and land during the American and African boreal summer monsoons plays a key role in maintaining a cross equatorial flow and a strong windstress along the equator, and thereby the equatorial upwelling. Feedbacks between convection, large-scale circulation, SST and clouds are highlighted from the differences between the two simulations. In one case, these feedbacks maintain the ITCZ in a quite realistic position, whereas in the other case the ITCZ is located too far south close to the equator.     

Dating of marine aragonite by electron spin resonance

Marine aragonite, in the form of corals and/or shells, provides useful markers of geological and archaeological events. It is, therefore, important to have simple and accurate methods of dating these materials. Electron spin resonance (ESR) has previously been shown to be a reliable method for establishing the age of aragonitic coral samples in the time period approximately 100 ka B.P. The primary purpose of the present work is to discuss the problems encountered in extending this method to considerably older samples, up to 600 ka BP in age. In this time period there are questions about the stability of the ESR signal. The samples investigated are aragonitic corals from reef terraces of Barbados, West Indies, all of which have previously been dated by the methods, and by U-series disequilibrium, for samples below the limit of this method. There is generally good agreement for samples up to about 300 ka in age; older samples, even unrecrystallized, appear younger when dated by ESR than by . The source of this discrepancy is not clear. The explanation of thermal fading is not adequate. However, it appears likely that in most cases ESR will be able to be used to date materials up to this age. Further investigation is needed to determine tests that will distinguish datable samples from non-datable ones.