bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reply to “Probability of chance correlations of earthquakes with predictions in areas of heterogeneous seismicity rate: The VAN Case,” by M. Wyss and A. Allmann
Authors: Varotsos P. , Eftaxias K. , Lazaridou M. , Dologlou E. , Hadjicontis V. 
Published: February 2004

All conclusions of Wyss and Allmann [1996] (hereafter cited as WA) are wrong, because their methodology is false. For example, WA's main conclusion reads: “the probability [P] that the observed correlations of [VAN] predictions with earthquakes (…11 out of 23 attempts) was due to chance is estimated as…96%…” However, when following WA's procedure exactly, and assuming that all 23 predictions (out of 23 attempts) are correct, we find a paradox, i.e., values of the probability P larger than unity. In view of this example, any further discussion on WA's claims becomes unnecessary. However, we proceed to detailed replies, point by point, in order to show that WA have also made several mistakes and major misinterpretations of the true content of VAN's statements.Characteristic examples of the various misinterpretations (and mistakes) made by WA include: (i) a direct comparison of predicted magnitude values with Ms(PDE), while VAN had clearly stated that the magnitude values mentioned in the predictions correspond to Ms(ATH), i.e., to ML+0.5. Such a comparison is not allowed because ML+0.5 significantly differs (i.e., on the average by 1.0 unit) from Ms(PDE), (ii) an addition (or deletion) of critical wording to the VAN statements (and predictions) so that they distort VAN's true meaning, (iii) the use of 22 day prediction time window in the large majority of predictions which, however, correspond to single SES (and hence to an 11 days prediction time window), (iv) an incorrect statement that Varotsos et al. [1993a,b] define the acceptable uncertainty as ΔM ≤ 1.0, while VAN repeatedly published that a prediction is accepted as successful only when ΔM ≤ 0.7, (v) an erroneous claim that when using SI‐NOA “12 out of 22 VAN predictions fail to conform to the error limits,” while the reader can easily check that only 6 (or 7) out of 23 cases deviate from the error limits. Furthermore, WA grossly overestimated the number of the earthquakes (EQs) that should have been predicted, i.e., while VAN clearly stated that predictions are issued only when the expected magnitude is larger than (or equal to) 5.0 units, WA erroneously demand that VAN should predict all EQs with Ms ≥ 4.3 or Ms ≥ 4.0. Hence they characterize as a “missed earthquake” any event with Ms≥ 4.3 (or Ms ≥ 4.0 respectively) for which prediction was not issued.Last but not least, we recall that Wyss and Baer [1981] published long term predictions in Greece (for the same time period discussed in this debate) ‐referring to expected EQs with magnitude 7.75‐ which turned out to be completely unsuccessful.
Reply II to “VAN: Candidacy and validation with the latest laws of the game,” by F. Mulargia and P. Gasperini and “Precursor candidacy and validation: The VAN Case so far,” by F. Mulargia and P. Gasperini
Authors: Varotsos P. , Eftaxias K. , Lazaridou M. 
Published: February 2004

A simple inspection of the Tables of Mulargia and Gasperini [1992, 1996a] that refer to the period 1987–1989 reveals the following two facts: (i) by recalling that predictions are issued only when the expected magnitude is Mpred ≥ 5.0, the true VAN success rate is 79% (for Δr ≤ 120km) while the (incorrect) success rate of 45% emerges when restricting only correlations that include earthquakes with MEQ≥5.0 are considered as successes, and (ii) the VAN alarm rate increases significantly for larger earthquake magnitudes, i.e., for MEQ≥5.0, 5.3, 5.5 and 5.8, the alarm rates are 22%, 36%, 50% and 60% respectively. These facts are inconsistent with their claim that “VAN results can be ascribed to chance.” This claim also contradicts the conclusions obtained from the calculations by Aceves et al. [1996], and by Honkura and Tanaka [1996].In a separate Section we give answers, point by point, to various statements made in the two papers by Mulargia and Gasperini [1996a,b]. Most of these statements are obviously untrue. For example, they claim that “VAN predictions have been documented primarily by circulating telegrams among the members of the VAN‐group” although: (i) the Greek Authorities (as well as 29 International Institutes) receive the VAN predictions well before the earthquake occurrence and (ii) it is extensively known that the two most destructive activities in Greece during the period 1987–1994 were publicly announced by VAN well in advance. Furthermore, Mulargia and Gasperini [1996a] claim that, for the period 1990–1992, VAN correctly predicted only 2 out of 16 EQs with Ms(=mb+0.3) ≥ 5.0; however, a check of the VAN data of this period (see Varotsos et al., 1993c) shows that the alarm rate is 8/20, for EQs with mb > 4.7, and increases to 3/4 for EQs with mb > 5.0.
Reply to “Probability of earthquake occurrence in Greece with special reference to the VAN predictions,” by Y. Honkura and N. Tanaka
Authors: Varotsos P. , Lazaridou M. 
Published: February 2004

The calculation of Honkura and Tanaka [1996] and that of Aceves et al. [1996], provide important tools for the clarification of the main question of this issue, i.e., whether or not the VAN predictions can be ascribed to chance.Honkura and Tanaka's [1996] calculation showed that, in a circular area with a radius of 120 km and for the time window of 22 days, the probability P of occurrence of an earthquake (EQ) with Ms ≥ 5.0 in Greece is less than 0.25, and even smaller for a time window of 11 days. For larger magnitude thresholds, i.e., Ms ≥ 5.5 or Ms ≥ 5.8 (and in view of Gutenberg‐Richter relation), their P‐value has to be drastically smaller. A simple comparison of these P‐values with the Tables of Mulargia and Gasperini [1992, 1996a] immediately reveals that VAN‐predictions cannot be ascribed to chance. Note that an inspection of the latter Tables leads to (i) the VAN success rate is 40∼45% (when considering correlations with earthquakes having MEQ ≥ 5.0 only), and (ii) the VAN alarm rates increase with the (earthquake) magnitude threshold, reaching to values of 50% and 60%, for MEQ ≥ 5.5 and MEQ ≥ 5.8 respectively.Another important point, which emerges from the calculation of Honkura and Tanaka [1996], is that “aftershocks must be treated carefully.” This strengthenes our remarks in Principles 4 and 5 of Varotsos et al. [1996a] that the inappropriate treatment of aftershocks in Mulargia and Gasperini’ [1992] calculation (which was based on Poisson distribution): (i) changed drastically the values of the significance level and (ii) turned a true “forward time correlation,” between predictions and earthquakes, to a “backward time association.” The latter point is also separately checked by Honkura and Tanaka [1996] who conclude that:“…with the backwards time correlation in mind… we could not find cases in which a high probability arises for the occurrence of an EQ of Ms ≥ 5.0 in the target area.” In this Reply we also proceed to some necessary clarifications, concerning the calculation of the “success rate” and “alarm rate” when a prediction method has, as expected, an experimental error in the magnitude determination.
Hydrothermal convection at mid‐ocean ridges: Influence of permeability anisotropy within a tilted triangular structure
Authors: Aron C. , Pezard P. A. , Angot Ph. , Laverne C. 
Published: February 2004

Recent results from seafloor exploration and crustal drilling are used to constrain the structures within which hydrothermal circulation occurs at mid‐ocean ridges (MOR). This hydrothermal activity is modeled numerically using a two‐dimensional triangular domain representing the extrusive layers. The configuration is heated both at an impermeable base and along the intrusion axis. The structure is characterized by dips of a few degrees towards the axis and permeability anisotropy (δ = KZ/KX). The temperature fields are computed for different hydrothermal regimes defined by variable axial heat flow values characterized by variable Rayleigh numbers (Ra*). These computed temperatures are compared to those deduced from basalt alteration mineralogy observed in seafloor samples and drillcores. The mean temperature of discharge zones is considered as limited to values between 60° and 100°C.In the isotropic case, the chosen geometry and boundary conditions are found to stabilize the convective process, which advocates against a time‐fluctuating behavior as a steady state is reached in an average time of 5000 years up to Ra* values as large as 600. However, Ra* values are unlikely to exceed 400, or to be smaller than 100 due to the mineralogical constraints. With Ra* larger than 100 and δ=1, a mean temperature of 25°C, compatible with celadonite‐nontronite and iron‐hydroxides mineralization, is obtained for the recharge zones. For a given axial heat flow and a similar permeability contrast, larger temperatures are obtained in subhorizontal settings than in subvertical ones. Small changes of permeability anisotropy are confirmed to induce large variations in temperatures and strength of the flow.
Simultaneous measurements of O+ and H+temperatures in the topside ionosphere over Arecibo
Authors: Sulzer Michael P. , González Sixto A. 
Published: February 2004

We have measured both proton (TH+) and oxygen ion (TO+) temperatures simultaneously from spectra obtained in the lower topside ionosphere using the Arecibo incoherent scatter radar (ISR). This is the first time that two ion temperatures and three ion compositions have been measured from the same IS spectrum, and, as far as we know, one of the first measurements of both ion temperatures in the ionosphere.First we describe our spectral‐domain analysis technique, emphasizing the ability to determine goodness of fit, which allows of the need for and effect of including a parameter to be numerically evaluated. We then show that common TH+ and TO+ allow insufficient freedom, and that separate temperatures are sufficient.A small negative bias in [He+] parameter is removed when the second temperature is allowed to be free while the H+ fraction is not significantly affected. We also show that the measurement cannot be made at altitudes where little O+ is present. The difference between TH+ and TO+ is zero (or at least very small) during the night, and rises to several hundred degrees at about 500 km shortly after sunrise. During the middle of the day the temperature difference declines (presumably due to higher densities) and then rises again before sunset.
The argon constraints on mantle structure
Authors: Allègre Claude J. , Hofmann Albrecht , O'Nions Keith 
Published: February 2004

The 40Ar budget of the Earth offers a powerful and straightforward argument in favour of the existence of a layered structure to the mantle.Whereas K‐Ar‐isotope systematics have been included as part of various discussions of mantle structure previously a simple and straightforward argument is presented here. Because 40Ar is produced by 40K the amount of K in the Earth may be constrained from 40Ar budgets. The atmospheric 40Ar budget implies that approximately half of all 40Ar produced within the Earth since its formation is retained within the solid Earth. It is argued that this additional 40Ar is located principally in the lower mantle.
Electromagnetic hybrid‐code simulation of magnetic reconnection: Velocity distribution functions of accelerated ions
Authors: Nakabayashi J. , Machida S. 
Published: February 2004

A 2‐1/2 dimensional electromagnetic hybrid simulation was conducted to explore particle acceleration in the magnetic reconnection process in the Earth magnetotail. By adding a localized anomalous resistivity to the neutral sheet of initial static Harris solution, we realized a spontaneous magnetic reconnection. We found that two kinds of characteristic electric fields were generated in addition to the conventional dawn‐to‐dusk electric field after the reconnection commenced. The first type of the electric field is directed toward the neutral sheet in the expanded plasma sheet boundary layer (PSBL), resulting in a dawnward drift of cold ions. The second type of electric field was directed as the conventional dawn to dusk component in the plasma sheet, but with a significantly large component away from the diffusion region. Though well‐developed slow mode shocks were not formed, this field played a significant role in plasma jet formation. The energy transfer from the electric field to the ions with the first type electric field was three times higher than with that the second type field. In addition to these perpendicular electric fields, the field‐aligned electric field in front of expanding plasma sheet (early‐phase plasmoid) caused a parallel ion acceleration. The dawnward plasma drift in the expanded plasma sheet and PSBL yielded a nonzero By field whose polarity showed an octupole structure with respect to the central diffusion region.The relevant forms of ion distribution functions predicted by the present model are also considered in this study. This model can be applied to the transient phase of the magnetic reconnection, i.e., the expansion phase of the magnetospheric substorms.
High resolution TEC monitoring method using permanent ground GPS receivers
Authors: Hernández‐Pajares M. , Juan J. M. , Sanz J. 
Published: February 2004

In this paper we propose a new and simple method for obtaining the ionospheric Total Electron Content (TEC) variations from GPS permanent station data, in a very precise manner and with high temporal and spatial resolution.The key idea is to use of the resonant period of 1 sidereal day between the Earth's rotation and the GPS satellite orbit periods, in order to obtain one TEC variation estimate directly from each ionospheric observation.This new strategy can be applied on both global and local scales, for instance to one single station. Its capabilities are shown in the application performed with the data gathered on 17, 18 and 19 October 1995 from 95 GPS permanent stations and 9 and 10 January 1997 (180 stations), coinciding with two major geomagnetic storms.
The TSS‐1R Mission: Overview and scientific context
Authors: Stone N. H. , Bonifazi C. 
Published: February 2004

The Tethered Satellite System (TSS) program is a binational collaboration between NASA and the Italian Space Agency (ASI) with NASA providing the Shuttle‐based deployer and tether and ASI providing a satellite especially designed for tethered deployment. Twelve science investigations (see Table 1) were supported by NASA, ASI, or the Air Force Philips Laboratory. The goals of the TSS‐IR mission, which was the second flight of the TSS hardware, were to provide unique opportunities to explore (1) certain space plasma‐electrodynamic processes—particularly those involved in the generation of ionospheric currents, and (2) the orbital mechanics of a gravity‐gradient stabilized system of two satellites linked by a long conducting tether.TSS‐IR was launched February 22, 1996 on STS‐75 into a 300‐km, circular orbit at 28.5° inclination. Satellite flyaway occurred at MET 3/00:27 and a unique data set was obtained over the next 5 hours as the tether was deployed to a length of 19,695 m. At MET 3/05:11, during a day pass, the tether suddenly broke near the top of the deployer boom. The break resulted from a flaw in the tether insulation which allowed the ignition of a strong electrical discharge that melted the tether. The operations that had begun at satellite flyaway, however, allowed significant science to be accomplished.
Research education
Authors: Hansen James , Harris Carolyn , Borenstein Samuel , Curran Brendan , Fox Mitchell 
Published: February 2004

IntroductionHow can we get the public to appreciate the way scientific understanding advances via iterative research? How can we provide females and underrepresented minorities an opportunity to be involved in science early enough in their schooling to make a difference in career motivation? How can research laboratories help improve science education in our schools and prepare students with skills that they will need in the workforce? We do not have the answers to these questions. Indeed, we are only beginning to work together, as researchers and educators, on these topics. However, the Editor, upon seeing the large number of student and educator coauthors on our paper in this issue of Journal of Geophysical Research, invited us to describe our fledgling program, with the hope of stimulating dialogue on a topic of increasing interest.
Introduction to special section: Maurice Ewing Symposium on Applications of Trace Substance Measurements to Oceanographic Problems
Authors: Schlosser Peter , Smethie William M. , Toggweiler J. Robert 
Published: February 2004

On October 16–20, 1995, a Maurice Ewing Symposium on Applications of Trace Substance Measurements to Oceanographic Problems was held at Biosphere 2 in Oracle, Arizona. The objectives of this symposium were (1) to review the status of tracer methodology for oceanographic research (technological advances and progress in applications), (2) to evaluate the potential of the individual tracers for regional and global studies of water mass formation and circulation in the ocean, and (3) to outline the role of tracers in calibration and improvement of global circulation models.Trace substances of natural and anthropogenic origin have been used to study circulation and mixing in the ocean for roughly the past 4 decades. In such studies the penetration and subsequent spreading of anthropogenic trace substances released to the ocean are observed and evaluated in terms of flow paths and mean transit and residence times of specific water masses. These studies are basically regional or global dye experiments. Additionally, the radioactive character of several natural tracers is used to determine the mean residence times of deep waters.
On the validity of the independent pixel approximation for boundary layer clouds observed during ASTEX
Authors: Zuidema Paquita , Evans K. Franklin 
Published: February 2004

The two‐dimensional radiative transfer behavior of nine marine stratocumulus clouds observed by cloud radar during the Atlantic Stratocumulus Transition Experiment is examined. The cloud radar resolves the vertical structure to 37.5 m. The method of [Frisch et al., 1995] is used to convert radar reflectivities to extinction fields. Three constructions of the same cloud field help elucidate underlying causes of variability: one is fully two‐dimensional, while the other two have vertically uniform extinction fields but possess either a flat cloud top or the original cloud top topography. Two‐dimensional solar radiative transfer results are compared with the independent pixel approximation (IPA) result.At the scale of the domain (≈ 7km) the IPA albedo bias is small, even after including vertical structure. Locally, in contrast, the direct solar beam interaction with cloud top geometry competes with radiative smoothing as the dominant radiative process. Power spectral analysis of nadir reflectances is dominated by radiative smoothing for overhead Sun, and side illumination/shadowing of cloud top bumps for low Sun. A method that incorporates direct beam interactions with the cloud geometry, in addition to radiative smoothing, significantly improves correlations of a smoothed IPA radiance field with the 2‐D reflectances. In a remote sensing application, optical depth and albedo retrieval biases from plane‐parallel theory depend on the spatial scale chosen to emulate a satellite pixel size. For scales less than a few kilometers and with low Sun, cloud top topography can cause large positive optical depth biases even when averaged over the entire domain. A larger spatial scales the negative IPA bias always dominates. Domain‐averaged monochromatic albedo retrieval errors remain below 0.005, a relative error of less then 1%.
Intravitreal sodium fluorescein enhances visualization of clear vitreous during vitreous surgery for macular hole: a safety and efficacy study
Authors: Das Taraprasad , Vedantham Vasumathy 
Published: February 2004

Abstract Purpose: To assess the safety and efficacy of sodium fluorescein (NaFl) as an aid for clear vitreous vitrectomy. Methods: In 50 consecutive cases of macular hole surgery, NaFl 0.6% prepared from 20% injectable dye was injected into the vitreous cavity after core vitrectomy so as to stain the clear formed vitreous. Results: NaFl stained the peripheral uncut clear vitreous green and improved the visualization for a safe and complete vitrectomy. No complications associated with the dye injection were noted. Conclusion: NaFl 0.6% can safely be used in the vitreous cavity for easy identification of clear uncut vitreous gel for clear vitreous vitrectomy. This enhances expeditious excision of this tissue.
Is directed donation misguided?
Authors: Sherwin Trevor , Coster Douglas J , La Nauze Jamie , Merry Alan , Pendergrast David , Armitage W John 
Published: February 2004

AbstractThe worldwide shortage of organs and tissue for transplant has led to many ethical discussions involving restrictions concerning organ and tissue donation, including living donations and payment for donation. Efforts are being made to increase the donor pool; however, it is timely to ask whether moral decisions such as the rejection of directed donations are defensible. In this Clinical Conundrum, six specialists delve into the ethical and practical issues surrounding directed donation of human organs and tissues with particular reference to its implications in the field of ophthalmology.
Comparison of the Proview pressure phosphene tonometer performed by the patient and examiner with the Goldmann applanation tonometer
Authors: Danesh‐Meyer Helen V , Niederer Rachel , Gaskin Brent J , Gamble Greg 
Published: February 2004

Abstract Objective: To compare the results of Proview pressure phosphene tonometry (PPPT) performed by the patient and an examiner with Goldmann applanation tonometry (GAT). Methods: A comparative case series of 96 (192 eyes) consecutive patients from a glaucoma clinic was conducted. Intraocular pressure (IOP) was measured with GAT by one examiner, PPPT by another examiner, and PPPT by the patient. All examiners were masked to the results from any preceding IOP measurement. Results: The coefficient of repeatability for repeated measurements for the GAT was ±0.48 mmHg. The limits of agreement for self‐measurement of IOP with the PPPT and examiner measured IOP with PPPT were 6.3 mmHg and 4.8 mmHg, respectively. The limits of agreement between GAT and self assessed PPPT were ±11.8 mmHg (mean difference of 0.63 mmHg). When the same comparison was made between GAT and examiner assessed PPPT, the results were limits of agreement of ±10 mmHg (mean difference of 2.86 mmHg). No significant difference was identified in the agreement of the GAT and the PPPT when subanalysed for age of patient or diagnosis (P > 0.05). The limits of agreement between self‐assessed IOP with the PPPT and the GAT were ±8.2 for those with IOP <20 mmHg and ±14.9 mmHg for those with IOP>20 mmHg. Conclusions: Poor agreement exists between IOP measured by GAT and PPPT measured by an examiner or by the patient.
Fluorescein angiographic monitoring of corneal vascularization in lipid keratopathy
Authors: Peter Jayanthi , Fraenkel Graham , Goggin Michael , Drew Anton 
Published: February 2004

AbstractThe use of digital fluorescein corneal angiography to assist argon laser photocoagulation is reported. Photocoagulation was performed on the vascular supply of lipid keratopathy in the left eye of a 44‐year‐old woman.