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Sample records for 30-km zony chaes

  1. Development of the Chae Optimal Supervision Environment Test

    ERIC Educational Resources Information Center

    Chae, Ki Byung

    2013-01-01

    The review of current supervision models and instruments revealed a crucial need for a valid, reliable instrument that assesses the quality of the supervision environment as a venue for promoting counselor development. Therefore, the primary purpose of this study was the construction and initial validation of the Chae Optimal Supervision…

  2. Direct solar radiation up to 30 km and stratification of attenuation components in the stratosphere.

    PubMed

    Kondratiev, K Y; Nicolsky, G A; Badinov, I Y; Andreev, S D

    1967-02-01

    The balloon apparatus and some of the results of the direct solar radiation investigations up to 30 km in the middle belt of the Soviet Union in 1961-1965 are briefly described. Measurements of total direct solar radiation showed that the aerosol extinction properties in the free atmosphere are rather considerable, not only up to 30 km but also at the higher levels. The layered character of the stratospheric optical structure is demonstrated. The dynamics of layers and the possible influence of volcanic activity is discussed. Spectral investigations in the 0.35-13 micro region demonstrated that the stratospheric humidity is small, approximating 10(-6)-10(-5) g/g. The measurements in the visible spectrum confirmed that stratospheric aerosol component is essential, the stratospheric optical density being about 10(-4)-10(-3) km(-1). Comparison of the results of spectral and integral investigations indicates that the aerosol ext nction is also dominant above 30 km. PMID:20057727

  3. The effect of creatine supplementation upon inflammatory and muscle soreness markers after a 30km race.

    PubMed

    Santos, R V T; Bassit, R A; Caperuto, E C; Costa Rosa, L F B P

    2004-09-01

    We have evaluated the effect of a creatine supplementation protocol upon inflammatory and muscle soreness markers: creatine kinase (CK), lactate dehydrogenase (LDH), prostaglandin E2) (PGE2) and tumor necrosis factor-alpha (TNF-alpha) after running 30km. Runners with previously experience in running marathons, with their personal best between 2.5-3h were supplemented for 5 days prior to the 30km race with 4 doses of 5g of creatine and 15g of maltodextrine per day while the control group received the same amount of maltodextrine. Pre-race blood samples were collected immediately before running the 30km, and 24h after the end of the test (the post-race samples). After the test, athletes from the control group presented an increase in plasma CK (4.4-fold), LDH (43%), PGE2 6.6-fold) and TNF-alpha (2.34-fold) concentrations, indicating a high level of cell injury and inflammation. Creatine supplementation attenuated the changes observed for CK (by 19%), PGE2 and TNF-alpha (by 60.9% and 33.7%, respectively, p<0.05) and abolished the increase in LDH plasma concentration observed after running 30km, The athletes did not present any side effects such as cramping, dehydration or diarrhea, neither during the period of supplementation, nor during the 30km race. All the athletes finished the race in a time equivalent to their personal best +/- 5.8%. These results indicate that creatine supplementation reduced cell damage and inflammation after an exhaustive intense race. PMID:15306159

  4. Risks from radionuclide migration to groundwater in the Chernobyl 30-km zone.

    PubMed

    Bugai, D A; Waters, R D; Dzhepo, S P; Skal'skij, A S

    1996-07-01

    Remediation of contaminated groundwater in the Chernobyl 30-km evacuation zone is frequently identified as a priority by technical experts and Chernobyl site officials in Ukraine. In order to evaluate the health risk basis for this groundwater remediation, we have estimated both on-site and off-site health risks caused by radionuclide migration to the groundwater and compared these risks with those from exposure to radioactive contamination on the ground surface. A simple and conservative analytical model was developed to assess radionuclide transport to the groundwater from the soil surface contaminated by radioactive fallout. 90Sr, the primary radioactive contaminant of concern for the groundwater-migration exposure pathway, was evaluated in the analysis. The estimated health risk to hypothetical, self-sufficient residents in the 30-km zone is dominated by external and internal irradiation (due primarily to ingestion of agricultural products) from 137Cs, which is present in soils of the 30-km zone in roughly equal proportion with 90Sr. The estimated risk from contaminated groundwater is approximately an order of magnitude lower. Analysis of 90Sr migration via groundwater to surface water and down-river population centers shows that, despite generally unfavorable environmental conditions in the 30-km exclusion zone, radionuclide transport via the groundwater pathway has potential to contribute only marginally to the off-site radiological risk, which is governed by wash-out of radionuclides from the contaminated river flood plain and catchment areas by surface water during spring snowmelt and rains. Health risks due to off-site radionuclide migration via groundwater are below the level requiring application of counter-measures. This analysis implies that, relative to other exposure pathways, there is little current or future health risk basis for the proposed complex and costly groundwater remediation measures in the 30-km zone. Therefore, these activities should

  5. Development and Standardization of Extended ChaeLee Korean Facial Expressions of Emotions

    PubMed Central

    Lee, Kyoung-Uk; Kim, JiEun; Yeon, Bora; Kim, Seung-Hwan

    2013-01-01

    Objective In recent years there has been an enormous increase of neuroscience research using the facial expressions of emotion. This has led to a need for ethnically specific facial expressions data, due to differences of facial emotion processing among different ethnicities. Methods Fifty professional actors were asked to pose with each of the following facial expressions in turn: happiness, sadness, fear, anger, disgust, surprise, and neutral. A total of 283 facial pictures of 40 actors were selected to be included in the validation study. Facial expression emotion identification was performed in a validation study by 104 healthy raters who provided emotion labeling, valence ratings, and arousal ratings. Results A total of 259 images of 37 actors were selected for inclusion in the Extended ChaeLee Korean Facial Expressions of Emotions tool, based on the analysis of results. In these images, the actors' mean age was 38±11.1 years (range 26-60 years), with 16 (43.2%) males and 21 (56.8%) females. The consistency varied by emotion type, showing the highest for happiness (95.5%) and the lowest for fear (49.0%). The mean scores for the valence ratings ranged from 4.0 (happiness) to 1.9 (sadness, anger, and disgust). The mean scores for the arousal ratings ranged from 3.7 (anger and fear) to 2.5 (neutral). Conclusion We obtained facial expressions from individuals of Korean ethnicity and performed a study to validate them. Our results provide a tool for the affective neurosciences which could be used for the investigation of mechanisms of emotion processing in healthy individuals as well as in patients with various psychiatric disorders. PMID:23798964

  6. GPS-aided gravimetry at 30 km altitude from a balloon-borne platform

    NASA Technical Reports Server (NTRS)

    Lazarewicz, Andrew R.; Evans, Alan G.

    1989-01-01

    A balloon-borne experiment, flown at 30 km altitude over New Mexico, was used to test dynamic differential Global Positioning System (GPS) tracking in support of gravimetry at high-altitudes. The experiment package contained a gravimeter (Vibrating String Accelerometer), a full complement of inertial instruments, a TI-4100 GPS receiver and a radar transponder. The flight was supported by two GPS receivers on the ground near the flight path. From the 8 hour flight, about a forty minute period was selected for analysis. Differential GPS phase measurements were used to estimate changes in position over the sample time interval, or average velocity. In addition to average velocity, differential positions and numerical averages of acceleration were obtained in three components. Gravitational acceleration was estimated by correcting for accelerations due to translational motion, ignoring all rotational effects.

  7. Optimum design of 30-km long-distance distributed optical fiber Raman temperature sensor system

    NASA Astrophysics Data System (ADS)

    Zhang, Zaixuan; Liu, Honglin; Wang, Jianfeng; Yu, Xiangdong; Jin, Yongxing; Kim, Insoo S.; Wu, Xiaobiao

    2005-02-01

    A 30km long distance distributed optical fiber Raman temperature sensor (DOFRTS) system has been made, it use new measuring temperature principle of optical fiber amplified anti-Stokes Raman spontaneous scattering. In the system, 1550nm erbium-doped optical fiber laser, a highness speed data acquisition card and signal processing technique are used. By using these technique, the problem of weak signal detection is resolved and signal to noise ratio is increased. All components of system are put into an intellectualized constant temperature box and work in constant temperature condition. Stability and environment adaptability are improved. By appraisal, performance of the system is listed as follows: length of single mode fiber: 31km, temperature rang:0-100°C (can be expanded), temperature measuring uncertainty:+/-2°C, temperature resolution:0.1°C, measurement time:432s, spatial resolution :3m.

  8. Cardiac Troponin T and I Release After a 30-km Run.

    PubMed

    Klinkenberg, Lieke J J; Luyten, Peter; van der Linden, Noreen; Urgel, Kim; Snijders, Daniëlle P C; Knackstedt, Christian; Dennert, Robert; Kietselaer, Bastiaan L J H; Mingels, Alma M A; Cardinaels, Eline P M; Peeters, Frederique E C M; van Suijlen, Jeroen D E; Ten Kate, Joop; Marsch, Elke; Theelen, Thomas L; Sluimer, Judith C; Wouters, Kristiaan; Bekers, Otto; Bekkers, Sebastiaan C A M; van Loon, Luc J C; van Dieijen-Visser, Marja P; Meex, Steven J R

    2016-07-15

    Prolonged endurance-type exercise is associated with elevated cardiac troponin (cTn) levels in asymptomatic recreational athletes. It is unclear whether exercise-induced cTn release mirrors a physiological or pathological underlying process. The aim of this study was to provide a direct comparison of the release kinetics of high-sensitivity cTnI (hs-cTnI) and T (hs-cTnT) after endurance-type exercise. In addition, the effect of remote ischemic preconditioning (RIPC), a cardioprotective strategy that limits ischemia-reperfusion injury, was investigated in a randomized controlled crossover manner. Twenty-five healthy volunteers completed an outdoor 30-km running trial preceded by RIPC (4 × 5 min 220 mm Hg unilateral occlusion) or control intervention. hs-cTnT, hs-cTnI, and sensitive cTnI (s-cTnI) concentrations were examined before, immediately after, 2 and 5 hours after the trial. The completion of a 30-km run resulted in a significant increase in circulating cTn (time: all p <0.001), with maximum hs-cTnT, hs-cTnI, and s-cTnI levels of 47 ± 27, 69 ± 62, and 82 ± 64 ng/L (mean ± SD), respectively. Maximum hs-cTnT concentrations were measured in 60% of the participants at 2 hours after exercise, compared with maximum hs-cTnI and s-cTnI concentrations at 5 hours in 84% and 80% of the participants. Application of an RIPC stimulus did not reduce exercise-induced cTn release (time × trial: all p >0.5). In conclusion, in contrast to acute myocardial infarction, maximum hs-cTnT levels after exercise precede maximum hs-cTnI levels. Distinct release kinetics of hs-cTnT and hs-cTnI and the absence of an effect of RIPC favors the concept that exercise-induced cTn release may be mechanistically distinct from cTn release in acute myocardial infarction. PMID:27282835

  9. Clouds in ECMWF's 30 KM Resolution Global Atmospheric Forecast Model (TL639)

    NASA Technical Reports Server (NTRS)

    Cahalan, R. F.; Morcrette, J. J.

    1999-01-01

    Global models of the general circulation of the atmosphere resolve a wide range of length scales, and in particular cloud structures extend from planetary scales to the smallest scales resolvable, now down to 30 km in state-of-the-art models. Even the highest resolution models do not resolve small-scale cloud phenomena seen, for example, in Landsat and other high-resolution satellite images of clouds. Unresolved small-scale disturbances often grow into larger ones through non-linear processes that transfer energy upscale. Understanding upscale cascades is of crucial importance in predicting current weather, and in parameterizing cloud-radiative processes that control long term climate. Several movie animations provide examples of the temporal and spatial variation of cloud fields produced in 4-day runs of the forecast model at the European Centre for Medium-Range Weather Forecasts (ECMWF) in Reading, England, at particular times and locations of simultaneous measurement field campaigns. model resolution is approximately 30 km horizontally (triangular truncation TL639) with 31 vertical levels from surface to stratosphere. Timestep of the model is about 10 minutes, but animation frames are 3 hours apart, at timesteps when the radiation is computed. The animations were prepared from an archive of several 4-day runs at the highest available model resolution, and archived at ECMWF. Cloud, wind and temperature fields in an approximately 1000 km X 1000 km box were retrieved from the archive, then approximately 60 Mb Vis5d files were prepared with the help of Graeme Kelly of ECMWF, and were compressed into MPEG files each less than 3 Mb. We discuss the interaction of clouds and radiation in the model, and compare the variability of cloud liquid as a function of scale to that seen in cloud observations made in intensive field campaigns. Comparison of high-resolution global runs to cloud-resolving models, and to lower resolution climate models is leading to better

  10. Communication between earthquake clusters separated by over 30 km supports simple volcano plumbing

    NASA Astrophysics Data System (ADS)

    Jonsdottir, K.; Jonasson, K.; Gudmundsson, M. T.; Hensch, M.; Hooper, A. J.; Holohan, E. P.; Sigmundsson, F.; Halldorsson, S. A.; Hognadottir, T.; Magnússon, E.; Pálsson, F.; Walter, T. R.; Ofeigsson, B.; Parks, M.; Roberts, M. J.; Hjorleifsdottir, V.; Cesca, S.; Guðmundsson, G.; Hreinsdottir, S.; Jarosch, A. H.; Dumont, S.; Fridriksdóttir, H. M.; Barsotti, S.; Einarsson, P.

    2015-12-01

    The subglacial Bárðarbunga volcano is composed of a large oval caldera (7x11 km) and fissures extending tens of kilometers away from the caldera along the rift zone, which marks the divergent plate boundary across Iceland. On August 16th, 2014 an intense seismic swarm started below the Bárðarbunga caldera and in the two weeks that followed a dyke migrated some 47 km laterally in the uppermost 6-10 km of the crust along the rift. The dyke propagation terminated in lava fields just north of Vatnajökull glacier, where a major (1.5 km3) six months long eruption took place. Intense earthquake activity in the caldera started in the period August 21-24 with over 70 M5 earthquakes accompanying slow caldera collapse, as verified by various geodetic measurements. The subsidence is likely due to magma withdrawal from a reservoir at depth beneath the caldera. During a five months period, October-February, the seismic activity was separated by over 30 km in two clusters; one along the caldera rims (due to piecewise caldera subsidence) and the other at the far end of the dyke (as a result of small shear movements). Here we present statistical analysis comparing the temporal behaviour of seismicity recorded in the two clusters. By comparing the earthquake rate in the dyke in temporal bins before and after caldera subsidence earthquakes to the rate away from these bins (background rate), we show that the number of dyke earthquakes was significantly higher (p <0.05) in the period 0-3 hours before a large earthquake (>M4.6) in the caldera. Increased dyke seismicity was also observed 0-3 hours following a large caldera earthquake. Elevated seismicity in the dyke before a large caldera earthquake may occur when a constriction in the dyke was reduced, followed by pressure drop in the chamber. Assuming that the large caldera earthquakes occurred when chamber pressure was lowest, the subsiding caldera piston may have caused temporary higher pressure in the dyke and thereby increased

  11. Kinetics of fuel particle weathering and {sup 90}Sr mobility in the Chernobyl 30-km exclusion zone

    SciTech Connect

    Kashparov, V.A.; Zvarich, S.I.; Protsak, V.P.; Levchuk, S.E.; Oughton, D.H.

    1999-03-01

    Weathering of fuel particles and the subsequent leaching of radionuclides causes {sup 90}Sr mobility in Chernobyl soils to increase with time after disposition. Studies of {sup 90}Sr speciation in soils collected in 1995 and 1996 from the Chernobyl 30-km exclusion zone have been used to calculate rates of fuel particles dissolution under natural environmental conditions. Results show that the velocity of fuel particle dissolution is primarily dependent on the physico-chemical characteristics of the particles and partially dependent on soil acidity. Compared to other areas, the fuel particle dissolution rate is significantly lower in the contaminated areas to the west of the Chernobyl reactor where deposited particles were presumably not oxidized prior to release. The data have been used to derive mathematical models that describe the rate of radionuclide leaching from fuel particles in the exclusion zone and changes in soil-to-plant transfer as a function of particle type and soil pH.

  12. [Long-term follow-up cytogenetic survey and biological dosimetry in persons evacuated from 30-km Chernobyl NPP zone].

    PubMed

    Maznik, N A

    2004-01-01

    The paper presents the results of the follow-up cytogenetic survey and biological dosimetry carried out in inhabitants of Pripiat' town and nearby villages, who were departured from the Chernobyl NPP 30-km exclusive zone during first days after the Chernobyl catastrophe. The unstable chromosome aberration level in inhabitants were significantly increased above control in terms up to 1 year after evacuation and declined gardually during next 14 years. In early period the cytogenetic damage frequency in evacuees showed no dependence on gender. The chromosome type aberration level appeared to be lower in young persons comparing with adults. The dicentrics plus centric rings yield had a positive correlation with duration of staying at Chernobyl zone. The average doses of protracted exposure were calculated from the dicentrics and centric rings yields; the dose estimations appeared to be 1.4 times higher in persons evacuated 3-11 days after the accident than that of in persons with shorter departure time. Uing the Bayesian analysis the probabilistic distribution of biological doses was constructed for the studied evacuees group. This distribution was characterized by a mean dose of 360 mGy, the modal doses of 200-450 mGy and 80% of probability density within the dose range 0-1000 mGy, that seems to be sufficient for considering the increased risk of late somatic radiation effects for this cohort. PMID:15571047

  13. Reduction of crop contamination by soil resuspension within the 30-km zone of the Chernobyl nuclear power plant.

    PubMed

    Sauras-Yera, Teresa; Tent, Joana; Ivanov, Yuri; Hinton, T G; Rauret, Gemma; Vallejo, Ramon

    2003-10-15

    A field experiment was conducted within the 30-km zone of the Chernobyl Nuclear Power Plant to analyze whether the application of mulching reduced resuspension of 137Cs contaminated soil in oat (Avena sativa) crops. In 1993, we applied a mulch treatment at a dose of 200 g m(-2), and soil resuspension was measured by estimating soil loadings onto plant surfaces from Ti concentrations in plants. In 1994, two mulch doses were applied, 200 and 50 g m(-2), and we estimated the contribution of soil resuspension by using artificial resuspension collection devices (ARC). In the 1993 experiment between 4.6 and 34.4% of the plant's total 137Cs contamination was attributed to external soil contamination. The mean amount of soil-derived 137Cs attached to vegetation was 124.7 Bq kg(-1)(plant) in control plots and 53.7 Bq kg(-1)(plant) in mulched plots. In the 1994 experiment, covering the soil with a mulch layer decreased the radiocesium content in ARC by about 70%. Results obtained in these experiments suggest that soil resuspension was a significant mechanism for plant contamination and that mulching was effective in reducing that contamination. PMID:14594366

  14. Expedition to the 30-km Chernobyl Exclusion Zone and the Utilization of its Experience in Education and Communication

    SciTech Connect

    Aszodi, Attila; Yamaji, Bogdan; Silye, Judit; Pazmandi, Tamas

    2006-07-01

    Between May 28 - June 4, 2005, under the organization of the Hungarian Nuclear Society (HNS) and the Hungarian Young Generation Network (HYGN) - which operates within the framework of the HNS - a scientific expedition visited the Chernobyl Nuclear Power Plant and the surrounding exclusion zone. The participants were young Hungarian nuclear professionals supervised by more experienced experts. The main scientific goals of the expedition were the followings: Get personal experiences in a direct way about the current status of the Chernobyl Power Plant and its surroundings, the contamination of the environment and about the doses. Gather information about the state of the shut down power plant and the shelter built above the damaged 4. unit. Training of young nuclear experts by performing on site measurements. The Hungarian expedition successfully achieved its objectives by performing wide-range of environmental and dosimetric measurements and collecting numerous biological and soil samples. Within the 30-km exclusion zone the influence of the accident occurred 20 years ago still could be measured clearly; however the level of the radioactivity is manageable in most places. The dosimetric measurements showed that no considerable exposure occurred among the members of the expedition. The analysis of samples has been started at the International Chernobyl Center in Slavutich. During the expedition not only environmental sampling and in-situ measurements were carried out but it was also well documented with photos and video recordings for educational, training and PR purposes. A documentary TV film was recorded during the expedition. The first-hand knowledge acquired during the expedition helps the authentic communication of the accident and its present-day consequences, which is especially important in 2006, 20 years after the Chernobyl accident. Since Ukraine and Hungary are neighbor countries the media constantly discuss the accident, the consequences and the risks of

  15. Can Pacing Be Regulated by Post-Activation Potentiation? Insights from a Self-Paced 30 km Trial in Half-Marathon Runners

    PubMed Central

    Del Rosso, Sebastián; Barros, Edilberto; Tonello, Laís; Oliveira-Silva, Iransé; Behm, David G.; Foster, Carl; Boullosa, Daniel A.

    2016-01-01

    Purpose Given the co-existence of post-activation potentiation (PAP) and fatigue within muscle, it is not known whether PAP could influence performance and pacing during distance running by moderating fatigue. The aim of this study was to assess the influence of PAP on pacing, jumping and other physiological measures during a self-paced 30 km trial. Methods Eleven male endurance-trained runners (half-marathon runners) volunteered to participate in this study. Runners participated in a multi-stage 30 km trial. Before the trial started, determination of baseline blood lactate (bLa) and countermovement jump (CMJ) height was performed. The self-paced 30 km trial consisted of 6 × 5 km splits. At the end of each 5 km split (60 s break), data on time to complete the split, CMJ height, Rating of Perceived Exertion (RPE) and blood lactate were collected while heart rate was continuously monitored. Results There was a significant decrease in speed (e.g. positive pacing strategy after the 4th split, p<0.05) with a progressive increase in RPE throughout the trial. Compared with baseline, CMJ height was significantly (p<0.05) greater than baseline and was maintained until the end of the trial with an increase after the 5th split, concomitant with a significant reduction in speed and an increase in RPE. Significant correlations were found between ΔCMJ and ΔSPEED (r = 0.77 to 0.87, p<0.05) at different time points as well as between RPE and speed (r = -0.61 to -0.82, p<0.05). Conclusion Our results indicates that fatigue and potentiation co-exist during long lasting endurance events, and that the observed increase in jump performance towards the end of the trial could be reflecting a greater potentiation potentially perhaps counteracting the effects of fatigue and preventing further reductions in speed. PMID:26934357

  16. Critical Evaluation of 0-30 km Profile Information in Ground-Based Zenith-Sky and Satellite-Measured Backscattered UV Radiation

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan; Petropavlovskikh, Irina; Deluishi, John; Einaudi, Franco (Technical Monitor)

    2000-01-01

    We now have several decades of experience in deriving vertical ozone profiles from the measurements of diffuse ultraviolet radiation by both ground and satellite-based instruments using Umkehr and BUV techniques. Continuing technological advances are pushing the state-of-the-art of these measurements to high spectral resolution and broader wavelength coverage. These modern instruments include the ground-based Brewer and satellite-based Global Ozone Monitoring Experiment (GOME) instruments, as well as advanced instruments being developed by ESA(SCIAMACHY), Netherlands(OMI) and Japan(ODUS). However, one of the issues that remains unresolved is the 0-30 km ozone profile information retrievable from these measurements. Though it is commonly believed that both the Umkehr and the satellite-based BUV techniques have very limited profile information below 30 km, there are those who argue that the data from these instruments should continue to be reported in this altitude range for they compare well with ozonesondes and hence there is useful scientific information. Others claim that the limitations of the Umkehr and BUV techniques are largely due to their low spectral resolution, and that the profile information below 30 km can be greatly improved by going to high spectral resolution instruments, such as Brewer and GOME. The purpose of this paper is to provide a critical evaluation of the 0-30 km ozone profile information in the various UV remote sensing techniques. We use a database of individual ozone profiles created using ozonesondes and SAGE and 4D ozone fields generated by data assimilation techniques to simulate radiances measured by the various techniques. We then apply a common inversion approach to all the methods to systematically examine how much profile information is available simply from the knowledge of total ozone, how much additional profile information is added by the traditional Dobson Umkehr and satellite buv techniques, and how much better one can do

  17. Penetration Experiments with 6061-T6511 Aluminum Targets and Spherical-Nose Steel Projectiles at Striking Velocities Between 0.5 and 3.0 km/s

    SciTech Connect

    Forrestal, M.J.; Piekutowski, A.J.

    1999-02-04

    We conducted depth of penetration experiments with 7.11-mm-diameter, 74.7-mm-long, spherical-nose, 4340 steel projectiles launched into 250-mm-diameter, 6061-T6511 aluminum targets. To show the effect of projectile strength, we used projectiles that had average Rockwell harnesses of R{sub c} = 36.6, 39.5, and 46.2. A powder gun and two-stage, light-gas guns launched the 0.023 kg projectiles at striking velocities between 0.5 and 3.0 km/s. Post-test radiographs of the targets showed three response regions as striking velocities increased: (1) the projectiles remained visibly undeformed, (2) the projectiles permanently deformed without erosion, and (3) the projectiles eroded and lost mass. To show the effect of projectile strength, we compared depth-of-penetration data as a function of striking velocity for spherical-nose rods with three Rockwell harnesses at striking velocities ranging from 0.5 to 3.0 km/s. To show the effect of nose shape, we compared penetration data for the spherical-nose projectiles with previously published data for ogive-nose projectiles.

  18. Determination of (129)I and (127)I concentration in soil samples from the Chernobyl 30-km zone by AMS and ICP-MS.

    PubMed

    Sahoo, Sarata Kumar; Muramatsu, Yasuyuki; Yoshida, Satoshi; Matsuzaki, Hiroyuki; Rühm, Werner

    2009-07-01

    A large amount of radioiodine isotopes (mainly (131)I, t(1/2) = 8 days) was released from the accident at Chernobyl Nuclear Power Plant (CNPP) in April-May 1986. An increase in childhood-thyroid cancer in the contaminated areas in Belarus, Russia and the Ukraine was demonstrated to be caused by radioiodine released at the time of the accident. However, there is a lack of quantitative data on the (131)I levels in the local environment (e.g. air, plant, soil). At this point, a long-lived iodine isotope, (129)I (t(1/2) = 15.7 million years), also released with a certain ratio to (131)I from CNPP, could be used for estimating the (131)I levels in the environment. In this paper we present analytical results of the (129)I concentrations and (129)I/(127)I atom ratios in soil samples collected from the CNPP exclusion zone (30-km zone), with the aim of assessing current contamination levels and distribution patterns. For the analysis of the iodine fraction in the investigated soil samples, the pyrohydrolysis method was utilized for separation of (127)I and (129)I nuclides, and subsequently their concentration was determined using inductively coupled plasma mass spectrometry (ICP-MS) and accelerator mass spectrometry (AMS), respectively. The concentration of (129)I and the (129)I/(127)I atom ratio in the surface soil samples in the 30 km-zone of CNPP ranged from 4.6 to 170 mBq/kg, and from 1.4 x 10(-6) to 13 x 10(-6), respectively. These values are significantly higher than those from global (129)I fallout, indicating that most of the measured (129)I was due to the deposition of the accident. Stable iodine concentrations in this area were found to be very low (below 1 ppm) for most of the samples, suggesting the environmental iodine levels in this area to be potentially low. The (129)I/(137)Cs activity ratio in surface and sub-surface soils was not so constant, i.e., in the range (7.3-20.2) x 10(-7). This might be due to the different behavior of deposition and/or migration

  19. Formation of continental crust in a temporally linked arc magma system from 5 to 30 km depth: ~ 90 Ma plutonism in the Cascades Crystalline Core composite arc section

    NASA Astrophysics Data System (ADS)

    Ratschbacher, B. C.; Miller, J. S.; Kent, A. J.; Miller, R. B.; Anderson, J. L.; Paterson, S. R.

    2015-12-01

    Continental crust has an andesitic bulk composition with a mafic lower crust and a granodioritic upper crust. The formation of stratified continental crust in general and the vertical extent of processes active in arc crustal columns leading to the differentiation of primitive, mantle-derived melts entering the lower crust are highly debated. To investigate where in the crustal column magma mixing, fractionation, assimilation and crystal growth occur and to what extent, we study the ~ 90 Ma magmatic flare-up event of the Cascades arc, a magma plumbing system from ~ 5 to 30 km depth. We focus on three intrusive complexes, emplaced at different depths during major regional shortening in an exceptionally thick crust (≥ 55 km1) but which are temporally related: the upper crustal Black Peak intrusion (1-3 kbar at 3.7 to 11 km; ~ 86.8 to 91.7 Ma2), the mid-crustal Mt. Stuart intrusion (3.5-4.0 kbar at 13 to 15 km; 90.8 and 96.3 Ma3) and the deep crustal Tenpeak intrusion (7 to 10 kbar at 25 to 37 km; 89.7 to 92.3 Ma4). These intrusive complexes are well characterized by geochronology showing that they have been constructed incrementally by multiple magma batches over their lifespans and thus allow the monitoring and comparison of geochemical parameters over time at different depths. We use a combination of whole rock major and trace element data and isotopes combined with detailed investigation of amphibole, which has been recognized to be important in the generation of calc-alkaline rocks in arcs to test the following hypotheses: (a) compositional bimodality is produced in the lower crust, whereas upper crustal levels are dominated by mixing to form intermediate compositions, or (b) differentiation occurs throughout the crustal column with different crystallizing phases and their compositions controlling the bulk chemistry. 1. Miller et al. 2009: GSA Special Paper 456, p. 125-149 2. Shea 2014: PhD thesis, Massachusetts Institute of Technology 3. Anderson et al. 2012

  20. Individual, social and physical environmental correlates of ‘never’ and ‘always’ cycling to school among 10 to 12 year old children living within a 3.0 km distance from school

    PubMed Central

    2012-01-01

    Background Cycling to school has been identified as an important target for increasing physical activity levels in children. However, knowledge about correlates of cycling to school is scarce as many studies did not make a distinction between walking and cycling to school. Moreover, correlates of cycling to school for those who live within a distance, that in theory would allow cycling to school, stay undiscovered. Therefore, this study examined individual, social and physical environmental correlates of never and always cycling to/from school among 10 to 12 year old Belgian children living within a 3.0 km distance from school. Methods 850 parents completed a questionnaire to assess personal, family, behavioral, cognitive, social and physical environmental factors related to the cycling behavior of their children. Parents indicated on a question matrix how many days a week their child (1) walked, (2) cycled, was (3) driven by car or (4) public transport to and from school during fall, winter and spring. Multivariate logistic regression analyses were conducted to examine the correlates. Results Overall, 39.3% of children never cycled to school and 16.5% of children always cycled to school. Children with high levels of independent mobility and good cycling skills perceived by their parents were more likely to always cycle to school (resp. OR 1.06; 95% CI 1.04-1.15 and OR 1.08; 95% CI 1.01-1.16) and less likely to never cycle to school (resp. OR 0.84; 95% CI 0.78-0.91 and OR 0.77; 95% CI 0.7-0.84). Children with friends who encourage them to cycle to school were more likely to always cycle to school (OR 1.08; 95% CI 1.01-1.15) and less likely to never cycle to school (OR 0.9; 95% CI 0.83-1.0). In addition, children with parents who encourage them to cycle to school were less likely to never cycle to school (OR 0.78; 95% CI 0.7-0.87). Regarding the physical environmental factors, only neighborhood traffic safety was significantly associated with cycling: i.e., children were more likely to always cycle to school if neighborhood traffic was perceived as safe by their parents (OR 1.18; 95% CI 1.07-1.31). Conclusion Individual, social and physical environmental factors were associated with children’s cycling behavior to/from school. However, the contribution of the physical environment is limited and highlights the fact that interventions for increasing cycling to school should not focus solely on the physical environment. PMID:23228003

  1. The Case for a Hubble Constant of 30 km s-1 Mpc-1.

    PubMed

    Bartlett, J G; Blanchard, A; Silk, J; Turner, M S

    1995-02-17

    Although recent determinations of the distance to the Virgo cluster based on Cepheid variable stars represent an important step in pinning down the Hubble constant, after 65 years a definitive determination of the Hubble constant still eludes cosmologists. At present, most of the observational determinations place the Hubble constant between 40 and 90 kilometers per second per megaparsec (km s(-1) Mpc(-1)). The case is made here for a Hubble constant that is even smaller than the lower bound of the accepted range on the basis of the great advantages, all theoretical in nature, of a Hubble constant of around 30 kilometers per second per megaparsec. Such a value for the Hubble cures all of the ills of the current theoretical orthodoxy, that is, a spatially flat universe composed predominantly of cold dark matter. PMID:17811436

  2. An innovative rotational Raman lidar to measure the temperature profile from the surface to 30 km altitude

    NASA Astrophysics Data System (ADS)

    Hauchecorne, Alain; Keckhut, Philippe; Mariscal, Jean-François; d'Almeida, Eric; Dahoo, Pierre-Richard; Porteneuve, Jacques

    2016-06-01

    A concept of innovative rotational Raman lidar with daylight measurement capability is proposed to measure the vertical profile of temperature from the ground to the middle stratosphere. The optical filtering is made using a Fabry-Pérot Interferometer with line spacing equal to the line spacing of the Raman spectrum. The detection is made using a linear PMT array operated in photon counting mode. We plan to build a prototype and to test it at the Haute-Provence Observatory lidar facility. to achieve a time resolution permitting the observation of small-scale atmospheric processes playing a role in the troposphere-stratosphere interaction as gravity waves. If successful, this project will open the possibility to consider a Raman space lidar for the global observation of atmospheric temperature profiles.

  3. In situ stratospheric measurements of HNO3 and HCl near 30 km using the balloon-borne laser in situ sensor tunable diode laser spectrometer

    NASA Technical Reports Server (NTRS)

    May, R. D.; Webster, C. R.

    1989-01-01

    In situ stratospheric measurements of the concentrations of the reservoir species HNO3 and HCl made during two flights of the high-resolution (0.0005/cm) balloon-borne laser in situ sensor instrument from Palestine, Texas, are reported. A measured HNO3 volume mixing ratio of 4.3 parts per billion by volume (ppbv) at 31 km altitude is about 1 ppbv larger than previously reported measurements at 32 deg N. An HCl mixing ratio of 1.6 ppbv at 29 km is in agreement with values obtained from earlier remote sensing techniques within the experimental uncertainties. Upper limits at 31 km of 0.4 ppbv for H2O2 and 0.2 ppbv for HOCl are also derived from analyses of spectra recorded near 1252/cm.

  4. Shackleton Crater Illumination

    NASA Video Gallery

    Simulated illumination conditions near the lunar South Pole. The 30km x 30km region highlights the Shackleton crater. The movie runs for 28 days, centered on the LCROSS impact date on October 9th, ...

  5. Impaired Perception of Emotional Expression in Amyotrophic Lateral Sclerosis

    PubMed Central

    Oh, Seong-il; Oh, Ki-Wook; Kim, Hee-Jin; Park, Jin-Seok

    2016-01-01

    Background and Purpose The increasing recognition that deficits in social emotions occur in amyotrophic lateral sclerosis (ALS) is helping to explain the spectrum of neuropsychological dysfunctions, thus supporting the view of ALS as a multisystem disorder involving neuropsychological deficits as well as motor deficits. The aim of this study was to characterize the emotion perception abilities of Korean patients with ALS based on the recognition of facial expressions. Methods Twenty-four patients with ALS and 24 age- and sex-matched healthy controls completed neuropsychological tests and facial emotion recognition tasks [ChaeLee Korean Facial Expressions of Emotions (ChaeLee-E)]. The ChaeLee-E test includes facial expressions for seven emotions: happiness, sadness, anger, disgust, fear, surprise, and neutral. Results The ability to perceive facial emotions was significantly worse among ALS patients performed than among healthy controls [65.2±18.0% vs. 77.1±6.6% (mean±SD), p=0.009]. Eight of the 24 patients (33%) scored below the 5th percentile score of controls for recognizing facial emotions. Conclusions Emotion perception deficits occur in Korean ALS patients, particularly regarding facial expressions of emotion. These findings expand the spectrum of cognitive and behavioral dysfunction associated with ALS into emotion processing dysfunction. PMID:27095526

  6. Lagrangian aspects of the axisymmetric Euler equation

    NASA Astrophysics Data System (ADS)

    Preston, Stephen C.; Sarria, Alejandro

    2016-03-01

    In this paper we are interested in geometric aspects of blowup in the axisymmetric three-dimensional (3D) Euler equations with swirl on a cylinder. Writing the equations in Lagrangian form for the flow derivative along either the axis or the boundary and imposing oddness on the vertical component of the flow, we extend some blowup criteria due to Chae, Constantin and Wu related to assumptions on the sign of the pressure Hessian. In addition. we give a geometric interpretation of the results, both in terms of the local geometry along trajectories and in terms of the Riemannian geometry of the volume-preserving diffeomorphism group.

  7. Construction and commissioning of a position-sensitive ionization chamber

    NASA Astrophysics Data System (ADS)

    Kwag, M. S.; Chae, K. Y.; Cha, S. M.; Kim, A.; Kim, M. J.; Lee, E. J.; Lee, J. H.

    2016-05-01

    A position-sensitive ionization chamber has been constructed and commissioned at the Physics Department of Sungkyunkwan University to extract position information on incident charged particles for future nuclear reaction measurements. By utilizing the newly-designed position-sensitive anodes and the previously-commissioned portable gas-filled ionization chamber by Chae et al., position information on incident particles could be obtained. The device was tested with an 241Am α-emitting source, and the standard deviation of the fitted Gaussian distribution was measured to be 1.76 mm when a collimator with a 2 mm hole was used.

  8. A New Tektite Discovery in the Guangdong Province, China, and the Search for the Source Crater of the Australasian Tektite Strewn Field

    NASA Astrophysics Data System (ADS)

    Kenkmann, T.; Maier, R. V.; Sturm, S.; Zhu, Meng-Hua.

    2014-09-01

    A new tektite location in South China is presented that belongs to the Australasian tektite strewnfield. We also investigated a 30 km circular structure in the Guangdong and Guangxi Province that might be related to the Australasian impact event.

  9. Development of a portable gas-filled ionization chamber

    NASA Astrophysics Data System (ADS)

    Chae, K. Y.; Cha, S. M.; Gwak, M. S.

    2014-02-01

    A new portable gas-filled ionization chamber has been designed and constructed at the Physics Department of Sung Kyun Kwan University. To overcome the maximum count rate of ˜105 particles per second of a conventional ionization chamber, which utilizes a Frisch grid, and to enhance the portability of a detector, we adopted the design of multiple electrodes and modified it from the original designs by Kimura et al. and Chae et al. The new design utilizes a stack of multiple electrodes installed perpendicular to the optical beam axis. This configuration provides a fast response time for the detector, which is essential for high-rate counting. The device has been tested with a 241Am ( t 1/2 = 432.2 years) radioactive α source, which mainly emits 5.486-MeV (branching ratio of 85%) and 5.443-MeV (branching ratio of 13%) α particles. An energy resolution of 6.3% was achieved.

  10. A rare case of concurrent signet-ring carcinoma of breast and microangiopathic hemolytic anemia.

    PubMed

    Lara, Kelly; Bae, Esther; Park, Hanna; Hussain, Farabi

    2016-01-01

    Microangiopathic hemolytic anemia (MAHA) can be an uncommon presentation of an underlying malignancy, most often due to signet-ring cell carcinoma (SRCC). Additionally, pure SRCC in a breast primary-tumor comprises <2% of all breast cancers (Shin SY, Park H, Chae SW, Woo HY. Microangiopathic hemolytic anemia as the first manifestation of metastatic signet-ring cell carcinoma of unknown origin: a case report and review of literature. Kor J Lab Med 2011;31:157-61). To the best of our knowledge, the combination of these two entities, pure breast primary SRCC along with MAHA, has not been reported. Here, we present such a rare case. We also evaluate the current literature regarding this and similar disease processes, of which evidence is scarce and further research is needed. PMID:27587305

  11. On 2-D Boussinesq equations for MHD convection with stratification effects

    NASA Astrophysics Data System (ADS)

    Bian, Dongfen; Gui, Guilong

    2016-08-01

    This paper is concerned with the two-dimensional magnetohydrodynamics-Boussinesq system with the temperature-dependent viscosity, thermal diffusivity and electrical conductivity. The first progress on this topic was made independently by Chae and Hou-Li [8,26] where the Boussinesq system with partial constant viscosity is obtained. Recently, Wang-Zhang [45] considered the temperature-dependent viscosity and thermal diffusivity, and Li-Xu [16] generalized the Wang-Zhang's result to the inviscid case with temperature-dependent thermal diffusivity. In this paper, we include the stratification and magnetic effects and consider the full system, in the framework of low regularity. We prove that, without any smallness assumption on the initial data, the full system is globally well-posed. Moreover, by applying the uniformly bounded generalized Oseen operator, time decay estimate of the solution is obtained.

  12. A rare case of concurrent signet-ring carcinoma of breast and microangiopathic hemolytic anemia†

    PubMed Central

    Lara, Kelly; Bae, Esther; Park, Hanna; Hussain, Farabi

    2016-01-01

    Microangiopathic hemolytic anemia (MAHA) can be an uncommon presentation of an underlying malignancy, most often due to signet-ring cell carcinoma (SRCC). Additionally, pure SRCC in a breast primary-tumor comprises <2% of all breast cancers (Shin SY, Park H, Chae SW, Woo HY. Microangiopathic hemolytic anemia as the first manifestation of metastatic signet-ring cell carcinoma of unknown origin: a case report and review of literature. Kor J Lab Med 2011;31:157–61). To the best of our knowledge, the combination of these two entities, pure breast primary SRCC along with MAHA, has not been reported. Here, we present such a rare case. We also evaluate the current literature regarding this and similar disease processes, of which evidence is scarce and further research is needed. PMID:27587305

  13. Magnetic helicity injection in NOAA 11261 associated with flares

    NASA Astrophysics Data System (ADS)

    Xu, Haiqing; Zhang, Hongqi; Su, Jiangtao; Ruan, Guiping; liu, Jihong

    2013-07-01

    Magnetic helicity was found important in understanding solar activities such as flares and coronal mass ejections (CME). Berger and field (1984) derived an expression for helicity flux dHm/dt, that can be applied to an individual solar active region (AR) occupying an area S of the photosphere, (1) \\begin{linenomath}dHm/dt=-2\\ints[(\\mathbf{Ap}\\cdot \\mathbf{V})\\mathbf{B}-(\\mathbf{Ap} \\cdot \\mathbf{B})\\mathbf{V}] dS, \\eqno{(1)}\\end{linenomath} where Ap is the vector potential of potential field, and V is the plasma velocity at the surface S. The first term describes the effect of magnetic footpoint motions on the surface S. The second term describes the flux of helicity advected through the surface when already twisted and/or writhed flux ropes emerge. Chae (2001) proposed a method of self-consistently determining magnetic helicity injection rate, dH/dt, using a time series of longitudinal magnetograms only: (2) \\begin{linenomath}dH/dt=-\\int2(\\textbf{A}p\\cdot \\textbf{V}LCT)BndS, \\eqno{(2)}\\end{linenomath} where n is the normal component of magnetic field. Ap is the vector potential computed from Bn by Fourier transform method. V LCT is the horizontal component of velocity determined by the technique of local correlation tracking (LCT). This technique was applied by some scientists (e.g., Chae et al., 2001; Nindos and Zhang, 2002; Romano et al., 2003). Magnetic helicity injection was found to be strongly correlated with the occurrence of major flares (Moon et al. 2002a, 2002b; Park et al., 2008; Labonte et al., 2007; Maeshiro et al., 2009).

  14. Soil organic components distribution in a podzol and the possible relations with the biological soil activities

    NASA Astrophysics Data System (ADS)

    Alvarez-Romero, Marta; Papa, Stefania; Verstraeten, Arne; Curcio, Elena; Cools, Nathalie; Lozano-Garcia, Beatriz; Parras-Alcántara, Luis; Coppola, Elio

    2016-04-01

    This research reports the preliminary results of a study based on the SOC (Soil Organic Carbon) fractionation in a pine forest soil (Pinus nigra). Hyperskeletic Albic Podzol soil (P113005, World Reference Base, 2014), described by the following sequence O-Ah-E-Bh-Bs-Cg, was investigated at Zoniën, Belgium. Total (TOC) and extractable (TEC) soil contents were determined by Italian official method of soil analysis. Different soil C fractions were also determined: Humic Acid Carbon (HAC) and Fulvic Acid Carbon (FAC). Not Humic Carbon (NHC) and Humin Carbon (Huc) fractions were obtained by difference. Along the mineral soil profile, therefore, were also tested some enzymatic activities, such as cellulase, xylanase, laccase and peroxidase, involved in the degradation of the main organic substance components, and dehydrogenase activity, like soil microbial biomass index. The results shows a differential TEC fractions distribution in the soil profile along three fronts of progress: (i) An E leaching horizon of TEC; Bh horizon (humic) of humic acids preferential accumulation, morphologically and analytically recognizable, in which humic are more insoluble that fulvic acids, and predominate over the latter; (ii) horizon Bs (spodic) in which fulvic acids are more soluble that humic acid, and predominate in their turn. All enzyme activities appear to be highest in the most superficial part of the mineral profile and decrease towards the deeper layers with different patterns. It is known that the enzymes production in a soil profile reflects the organic substrates availability, which in turn influences the density and the composition of the microbial population. The deeper soil horizons contain microbial communities adapted and specialized to their environment and, therefore, different from those present on the surface The results suggest that the fractionation technique of TEC is appropriate to interpret the podsolisation phenomenon that is the preferential distribution of

  15. High Resolution Regional Climate Modeling of the Irrigation Cooling Effect in California

    NASA Astrophysics Data System (ADS)

    Snyder, M. A.; Kueppers, L. M.; O'Brien, T.; Sloan, L. C.

    2007-12-01

    Recent research on the impact of irrigation on climate using regional climate models (RCMs) has revealed the presence of an irrigation cooling effect (ICE). By introducing large amounts of water to the land surface via irrigation there is a substantial decrease in daytime surface air temperatures during the dry season in California. Previous studies of the ICE in California utilized RCMs with horizontal resolution 30 km x 30 km. We have completed new experiments at 10 km x 10 km resolution for an 11-year time period from January 1 1979 to January 1 1990. The higher resolution allows for an improved representation of topography, which plays an important role in influencing the regional and local climate of California. An initial comparison of the 30 km and 10 km experiments reveals interesting similarities and differences in surface air temperature, humidity, and the surface energy budget. We also examined the changes in the winds due to irrigation between the 30 km and 10 km experiments. The cooling induced by irrigation leads to an increase in surface air pressure over the irrigated areas in California's Central Valley, which leads to a decrease in near surface onshore flow during the dry season. This onshore flow plays an important role for many crops, particularly wine grapes. By comparing the 30 km and 10 km experiments we are able to better quantify the uncertainty of the magnitude of changes in onshore flow.

  16. Equivalent strike-slip earthquake cycles in half-space and lithosphere-asthenosphere earth models

    USGS Publications Warehouse

    Savage, J.C.

    1990-01-01

    By virtue of the images used in the dislocation solution, the deformation at the free surface produced throughout the earthquake cycle by slippage on a long strike-slip fault in an Earth model consisting of an elastic plate (lithosphere) overlying a viscoelastic half-space (asthenosphere) can be duplicated by prescribed slip on a vertical fault embedded in an elastic half-space. Inversion of 1973-1988 geodetic measurements of deformation across the segment of the San Andreas fault in the Transverse Ranges north of Los Angeles for the half-space equivalent slip distribution suggests no significant slip on the fault above 30 km and a uniform slip rate of 36 mm/yr below 30 km. One equivalent lithosphere-asthenosphere model would have a 30-km thick lithosphere and an asthenosphere relaxation time greater than 33 years, but other models are possible. -from Author

  17. Dust productivity and impact collision of the asteroid (596) Scheila

    NASA Astrophysics Data System (ADS)

    Neslusan, L.; Ivanova, O.; Husarik, M.; Svoren, J.; Krisandova, Z. Seman

    2016-06-01

    Photometric observations of asteroid (596) Scheila were obtained during and after its 2010 outburst. The estimated radius of the body (spherical approximation of the asteroidal body) was 51.2±3.0 km and 50.6±3.0 km for different methods. The ejected dust mass from the asteroid ranged from 2.5 ×107 to 3.4 ×107 kg for different methods. An impact mechanism for triggering Scheila's activity is discussed. A few days before the impact, Scheila passed through the corridors of two potential cometary streams.

  18. INVESTIGATION OF PHOTOCHEMICAL MODELING OF POINT SOURCE POLLUTANTS WITH EULERIAN GRID AND LAGRANGIAN PLUME APPROACHES

    EPA Science Inventory

    In this paper, results of Eulerian grid and Lagrangian photochemical model simulations of emissions from a major elevated point source are presented. eries of simulations with grid sizes varying from 30 km to 2 km were performed with the Urban Airshed Model, a photochemical grid ...

  19. Effects of Automobile Commute Characteristics on Affect and Job Candidate Evaluations: A Field Experiment

    ERIC Educational Resources Information Center

    Van Rooy, David L.

    2006-01-01

    The current study assesses the effects of the commuting environment on affective states and hiring decisions. A total of 136 undergraduate females were randomly assigned to one of four conditions based on the length (10 km vs. 30 km) and level of congestion (low vs. high) during a commute. Multivariate analyses of variance indicate that affective…

  20. PATHOGENIC PHYTOPHTHORA SPECIES IN SAN JOAQUIN VALLEY IRRIGATION WATER SOURCES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface sources of irrigation water including the Kings River and three canals were assayed for Phytophthora spp. at six locations in the San Joaquin Valley within 30 km of Hanford, CA. Four nylon-mesh bags, each containing three firm, green pear fruits (separated by Styrofoam blocks) as bait for Ph...

  1. Sagebrush wildfire effects on soil chemistry: A temporal and spatial study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In sagebrush ecosystems, surface soil nutrient availability, particularly of N, often increases immediately following wildfire. However, little is known on how soil N availability and other nutrients, change over time post-wildfire. In October 2013, a wildfire approximately 30 km north of Reno, NV o...

  2. The largest neutron-star mass yet recorded has broad implications

    SciTech Connect

    Schwarzschild, Bertram

    2011-01-15

    Neutron stars are presumed to contain the densest matter in the cosmos. These remnants of core-collapse supernovae pack more than the Sun's mass (M{sub {center_dot}}) into a sphere less than 30 km across. There is considerable uncertainty about the character of matter squeezed to such ultrahigh densities, which cannot be reproduced in the laboratory.

  3. High-latitude stratospheric winds near summer solstice - The diurnal and semidiurnal solar tides

    NASA Technical Reports Server (NTRS)

    Neubert, T.; Iversen, I. B.; Madsen, M. M.; Dangelo, N.

    1983-01-01

    A technique for studying winds and tides at altitudes of approximately 30 km is the continuous and precise tracking of zero-pressure, stratospheric balloons. The CONSOL navigation system allows tracking of a balloon over the North Atlantic for two days or longer. Tidal wind data from 14 balloon trajectories (approximately 670 balloon hours) are presented and compared with theoretical predictions.

  4. Active Learning in the Atmospheric Science Classroom and beyond through High-Altitude Ballooning

    ERIC Educational Resources Information Center

    Coleman, Jill S. M.; Mitchell, Melissa

    2014-01-01

    This article describes the implementation of high-altitude balloon (HAB) research into a variety of undergraduate atmospheric science classes as a means of increasing active student engagement in real-world, problem-solving events. Because high-altitude balloons are capable of reaching heights of 80,000-100,000 ft (24-30 km), they provide a…

  5. Aviation weather service requirements, 1980 - 1990

    NASA Technical Reports Server (NTRS)

    Lieurance, N. A.

    1977-01-01

    Future aviation weather needs are discussed. Priority weather requirements and deficiencies existing for weather observations and forecast services in terminal areas are presented. Needs in en route operations up to 30 km are addressed with emphasis on turbulence, presence of suspended ice and water particles, SST to supersonic speeds, solar radiation, ozone, and sonic booms. Some conclusions are drawn and recommendations are presented.

  6. [Dynamics of tritium content in flood-lands reservoirs of the Pripyat river and cooling pond of the Chernobyl nuclear plant].

    PubMed

    Gudkov, D I

    1999-01-01

    Tritium content in water from natural and artificial reservoirs within 30-km exclusion zone of the Chernobyl NPP has been determined. The increase of Tritium activity in the involved water reserwous has been registered in May 1994 and April 1995. As supposed the source of the increase, nuclear power plants, equipped with WWER reactors and located in catchment area of Pripyat river. PMID:10689425

  7. The stratospheric aerosol content above Spitsbergen during winter 1991/92

    SciTech Connect

    Beyerle, G.; Neuber, R. )

    1994-06-22

    This paper summarizes the lidar measurements made at Spitsbergen (79[degrees]N) during the period of EASOE. The lidar can see backscatter and depolarization effects from the tropopause to 30 km. No aerosols were detected above 20 km until the breakup of the polar vortex. Stratospheric loading from the Pinatubo eruption were clearly visible at lower altitudes.

  8. Stratospheric plume dispersion: Measurements from STS and Titan solid rocket motor exhaust. Technical report

    SciTech Connect

    Beiting, E.J.

    1999-04-20

    Plume expansion was measured from nine Space Shuttle and Titan IV vehicles at altitudes of 18, 24, and 30 km in the stratosphere. The plume diameters were inferred from electronic images of polarized, near-infrared solar radiation scattered from the exhaust particles, and these diameters were found to increase linearly with time. The expansion rate was measured for as long as 50 min after the vehicle reached altitude. Measurements made simultaneously at multiple altitudes showed that the expansion rate increased with increasing altitude for six measurements made at Cape Canaveral but decreased between 24 and 30 km for the one measurement made at Vandenberg AFB. The average expansion rates for all measurements are 4.3 {+-} 1.0 m/s at 18 km, 6.8 {+-} 1.9 m/s at 24 km, and 8.7 {+-} 2.5 m/s at 30 km. Expansion rates varied from launch to launch by as much as a factor of 1.6 at 18 km, 2.2 at 24 km, and 2.7 at 30 km. No correlation between the expansion rate and wind speed or shear was evident. These data are compared to several models for diffusivity and are used to update a comprehensive particle model of solid rocket motor exhaust in the stratosphere. The expansion rates are required by models to calculate the spatial extent and temporal persistence of the local stratospheric ozone depletion cause by solid rocket exhaust.

  9. Structural response to 3D simulated earthquake motions in San Bernardino Valley

    USGS Publications Warehouse

    Safak, E.; Frankel, A.

    1994-01-01

    Structural repsonse to one- and three-dimensional (3D) simulated motions in San Bernardino Valley from a hypothetical earthquake along the San Andreas fault with moment magnitude 6.5 and rupture length of 30km is investigated. The results show that the ground motions and the structural response vary dramatically with the type of simulation and the location. -from Authors

  10. 40 CFR Appendix IV to Part 86 - Durability Driving Schedules

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... speed to 20 m.p.h. followed by light accelerations to the base speed. The 10th lap is run at a constant.... In addition, there are 5 light declerations each lap from the base speed to 30 km/h followed by light... to Part 86—Durability Driving Schedules (a) Durability Driving Schedule for Light-Duty Vehicles...

  11. ACROSS NORTH AMERICA TRACER EXPERIMENT (ANATEX) MODEL EVALUATION STUDY

    EPA Science Inventory

    Three perfluorocarbon tracer gases were released at 2.5-day or 5.0-day intervals from two sites in central North America and sampled for 24-h periods at 77 surface sites. he source-receptor distances ranged from less than 30 km to 3,000 km. he data were used to evaluate the long-...

  12. Flat-field and Dark Frame Corrections for IRIS Data

    NASA Astrophysics Data System (ADS)

    Saar, S. H.; Jaeggli, S. A.; Bush, R. I.; Boerner, P.; Wuelser, J.; Tarbell, T. D.; Lites, B. W.; De Pontieu, B.

    2013-12-01

    We discuss the development of flat-field and dark frame corrections for Interface Region Imaging Spectrograph (IRIS) data. Flat-fields for IRIS were taken prior to launch using a lamp filtered to NUV wavelengths; following launch the Sun itself was used as a flat-field source. The solar flat-field for the slit-jaw imagers is constructed using the Chae method, which extracts the moving object and fixed gain patterns from a set of dithered images. The spectrographic flat-fields are produced by significantly defocusing the telescope and averaging many images in a scan to remove solar structure, so that the average spectral profile can be removed. A given dark frame consists of pedestal and dark current components. In IRIS, both are temperature dependent, though they respond to different measured temperatures; the dark current is also exposure time dependent. Each CCD readout port has a slightly different temperature and exposure time response. We have analyzed a series of dark frames over an IRIS orbit to calibrate for these effects. We plan to continue to monitor the flat-field and dark frames regularly for any changes.

  13. Ethics in Prion Disease

    PubMed Central

    Bechtel, Kendra; Geschwind, Michael D.

    2013-01-01

    This paper is intended to discuss some of the scientific and ethical issues that are created by increased research efforts towards earlier diagnosis, as well as to treatment of, human prion diseases (and related dementias), including the resulting consequences for individuals, their families, and society. Most patients with prion disease currently are diagnosed when they are about 2/3 of the way through their disease course (Geschwind, Kuo et al. 2010; Paterson, Torres-Chae et al. 2012), when the disease has progressed so far that even treatments that stop the disease process would probably have little benefit. Although there are currently no treatments available for prion diseases, we and others have realized that we must diagnose patients earlier and with greater accuracy so that future treatments have hope of success. As approximately 15% of prion diseases have a autosomal dominant genetic etiology, this further adds to the complexity of ethical issues, particularly regarding when to conduct genetic testing, release of genetic results, and when or if to implement experimental therapies. Human prion diseases are both infectious and transmissible; great care is required to balance the needs of the family and individual with both public health needs and strained hospital budgets. It is essential to proactively examine and address the ethical issues involved, as well as to define and in turn provide best standards of care. PMID:23906487

  14. Fast and Accurate Fourier Series Solutions to Gravitational Lensing by a General Family of Two-Power-Law Mass Distributions

    NASA Astrophysics Data System (ADS)

    Chae, Kyu-Hyun

    2002-04-01

    Fourier series solutions to the deflection and magnification by a family of three-dimensional cusped two-power-law ellipsoidal mass distributions are presented. The cusped two-power-law ellipsoidal mass distributions are characterized by inner and outer power-law radial indices and a break (or transition) radius. The model family includes mass models mimicking Jaffe, Hernquist, and η models and dark matter halo profiles from numerical simulations. The Fourier series solutions for the cusped two-power-law mass distributions are relatively simple and allow a very fast calculation, even for a chosen small fractional calculational error (e.g., 10-5). These results will be particularly useful for studying lensed systems that provide a number of accurate lensing constraints and for systematic analyses of large numbers of lenses. Subroutines employing these results for the two-power-law model and the results by Chae, Khersonsky, & Turnshek for the generalized single-power-law mass model are made publicly available.

  15. Simulation of d(7Be,t)6Be with Fresco, and investigation of resonant states of 6Be

    NASA Astrophysics Data System (ADS)

    Pelham, Timothy

    2008-10-01

    An ongoing study is presented into the resonant states of 6Be via simulation of d(7Be,t)6Be with Fresco to investigate the results of ``Searching for resonances in the unbound 6Be nucleus'' a paper by K.Y. Chae [1]. In this paper the d(7Be,t)6Be reaction was studied to search for resonances in the 6Be nucleus that may be used to increase our knowledge of the 3He(3He,2p)4He reaction. A 100-MeV 7Be beam from the Holifield Radioactive Ion Beam Facility (HRIBF) was used to bombard CD2 targets, and tritons were detected by the Silicon Detector Array (SIDAR). It was concluded that a combination of reaction mechanisms are necessary to account for the observed triton energy spectrum. This will be further investigated by simulating the various reaction mechanisms with Fresco to try to reproduce and explain these results. Preliminary Results will be presented.

  16. An Experiment to Investigate the Role of Neutrals in Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Lawrence, Eric; Yoo, Jongsoo; Yamada, Masaaki; Ji, Hantao; Dorfman, Seth; Tharp, Tim; Myers, Clayton

    2010-11-01

    Magnetic reconnection in the solar chromosphere has become a topic of recent interest as it may be a source of energy transfer into the corona [1], and observations show evidence of fast reconnection [2]. Unlike the corona, the plasma in the chromosphere is relatively cool (T ˜10^4 K) and is weakly to partially ionized (nn/n ˜10^0-10^4). Furthermore, simulations have shown that the reconnection rate can depend on the ionization fraction and neutral collisionality [3]. Damping due to ion-neutral viscosity may also play a role. In the Magnetic Reconnection Experiment (MRX), we plan to study the effects of neutrals on reconnection in a controlled laboratory setting. A optical probe diagnostic is used to measure neutral density, and we plan to develop a UV diagnostic to facilitate comparisons with solar observations. Initial pressure scans have shown that we can access a parameter space relevant to the chromosphere. [4pt] [1] P. A. Sturrock, ApJ 521, 451 (1999).[0pt] [2] J. Chae, et al., J. Korean Astron. Soc., 36, 13 (2003).[0pt] [3] P. D. Smith, et al., A&A 486, 569 (2008).

  17. Robust hermetic packaging techniques for MEMS integrated microsystems.

    SciTech Connect

    Chae, Junseok; Stark, Brian H.; Kuo, Andrew; Oliver, Andrew David; Najafi, Khalil

    2005-03-01

    This work is the result of a Sandia National Laboratories LDRD funded fellowship at the University of Michigan. Although, guidance and suggestions were offered by Sandia, the work contained here is primarily the work of Brian H. Stark, and his advisor, Professor Khalil Najafi. Junseok Chae, Andrew Kuo, and their coworkers at the University of Michigan helped to record some of the data. The following is an abstract of their work. We have developed a vacuum packaging technology using a thick nickel film to seal MEMS structures at the wafer level. The package is fabricated in a three-mask process by electroplating a 40 micro-meter thick nickel film over an 8 micro-meter sacrificial photoresist that is removed prior to package sealing. Implementation of electrical feedthroughs in this process requires no planarization. The large release channel enables an 800x800 micro-meter package to be released in less than three hours. Several mechanisms, based upon localized melting and lead/tin solder bumping, for sealing the release channel have been investigated. We have also developed Pirani gauges, integrated with this package, which can be used to establish the hermeticity of the different sealing technologies. They have measured a sealing pressure of approximately 1.5 Torr. Our work differs from previous Pirani gauges in that we utilize a novel doubly anchored structure that stiffens the structural membrane while not substantially degrading performance in order to measure fine leak rates.

  18. Impact on the earth, ocean and atmosphere

    NASA Technical Reports Server (NTRS)

    Ahrens, Thomas J.; O'Keefe, John D.

    1987-01-01

    On the basis of finite-difference techniques, cratering flow calculations are used to obtain the spatial attenuation of shock pressure with radius along the impact axis for the impact of silicate rock and iron impactors on a silicate half-space at speeds of 5 to 45 km/sec. Upon impact of a 10 to 30 km diameter silicate or water object onto a 5 km deep ocean overlying a silicate half-space planet at 30 km/sec, it is found that from 12 to 15 percent of the incident energy is coupled into the water. The mass of atmosphere lost due to impacts of 1 to 5 km radius projectiles is calculated.

  19. Pure Rotational Raman Lidar for Temperature Measurements from 5-40 Km Over Wuhan, China

    NASA Astrophysics Data System (ADS)

    Li, Yajuan; Song, Shalei; Yang, Yong; Li, Faquan; Cheng, Xuewu; Chen, Zhenwei; Liu, Linmei; McCormick, M. Patrick; Gong, Shunsheng

    2016-06-01

    In this paper a pure rotational Raman lidar (PRR) was established for the atmospheric temperature measurements from 5 km to 40 km over Wuhan, China (30.5°N, 114.5°E). To extract the expected PRR signals and simultaneously suppress the elastically backscattered light, a high-spectral resolution polychromator for light splitting and filtering was designed. Observational results revealed that the temperature difference measured by PRR lidar and the local radiosonde below 30 km was less than 3.0 K. The good agreement validated the reliability of the PRR lidar. With the 1-h integration and 150-m spatial resolution, the statistical temperature error for PRR lidar increases from 0.4 K at 10 km up to 4 K at altitudes of about 30 km. In addition, the whole night temperature profiles were obtained for study of the long-term observation of atmospheric fluctuations.

  20. Chromospheric, transition layer and X-ray emission for stars with different rotational velocities

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, E.

    1982-01-01

    In agreement with previous findings for the MgII k line emission in F stars an increase of Lya and transition layer emission with increasing V sub r sin i, if v sub r sin i greater than 30 km/sec. was not found. For V sub r sin i 30 km/sec., the measured line intensities are consistent with an increase in emission with increasing V sub r sin i. Such a relation between emission and rotation for single stars is also in agreement with X-ray observations. For the young F stars in the Hyades we find generally enhanced emission independently of rotational velocities. The enhancement is most pronounced for low excitation lines.

  1. Cape Canaveral, Florida range reference atmosphere 0-70 km altitude

    NASA Technical Reports Server (NTRS)

    Tingle, A. (Editor)

    1983-01-01

    The RRA contains tabulations for monthly and annual means, standard deviations, skewness coefficients for wind speed, pressure temperature, density, water vapor pressure, virtual temperature, dew-point temperature, and the means and standard deviations for the zonal and meridional wind components and the linear (product moment) correlation coefficient between the wind components. These statistical parameters are tabulated at the station elevation and at 1 km intervals from sea level to 30 km and at 2 km intervals from 30 to 90 km altitude. The wind statistics are given at approximately 10 m above the station elevations and at altitudes with respect to mean sea level thereafter. For those range sites without rocketsonde measurements, the RRAs terminate at 30 km altitude or they are extended, if required, when rocketsonde data from a nearby launch site are available. There are four sets of tables for each of the 12 monthly reference periods and the annual reference period.

  2. Low-emissivity impact craters on Venus

    NASA Technical Reports Server (NTRS)

    Weitz, C. M.; Elachi, C.; Moore, H. J.; Basilevsky, A. T.; Ivanov, B. A.; Schaber, G. G.

    1992-01-01

    An analysis of 144 impact craters on Venus has shown that 11 of these have floors with average emissivities lower than 0.8. The remaining craters have emissivities between 0.8 and 0.9, independent of the specific backscatter cross section of the crater floors. These 144 impact craters were chosen from a possible 164 craters with diameters greater than 30 km as identified by researchers for 89 percent of the surface of Venus. We have only looked at craters below 6053.5 km altitude because a mineralogical change causes high reflectivity/low emissivity above the altitude. We have also excluded all craters with diameters smaller than 30 km because the emissivity footprint at periapsis is 16 x 24 km and becomes larger at the poles.

  3. Research study on neutral thermodynamic atmospheric model. [for space shuttle mission and abort trajectory

    NASA Technical Reports Server (NTRS)

    Hargraves, W. R.; Delulio, E. B.; Justus, C. G.

    1977-01-01

    The Global Reference Atmospheric Model is used along with the revised perturbation statistics to evaluate and computer graph various atmospheric statistics along a space shuttle reference mission and abort trajectory. The trajectory plots are height vs. ground range, with height from ground level to 155 km and ground range along the reentry trajectory. Cross sectional plots, height vs. latitude or longitude, are also generated for 80 deg longitude, with heights from 30 km to 90 km and latitude from -90 deg to +90 deg, and for 45 deg latitude, with heights from 30 km to 90 km and longitudes from 180 deg E to 180 deg W. The variables plotted are monthly average pressure, density, temperature, wind components, and wind speed and standard deviations and 99th inter-percentile range for each of these variables.

  4. El Chichon and 'mystery cloud' aerosols between 30 and 55 km Global observations from the SME visible spectrometer

    NASA Technical Reports Server (NTRS)

    Clancy, R. T.

    1986-01-01

    Visible limb radiances measured by the Solar Mesosphere Explorer (SME) are used to obtain volume scattering ratios for aerosol loading in the 30-55 km altitude range of the stratosphere. Global maps of these ratios are presented for the period January 1982 to August 1984. Significant aerosol scattering from the 'mystery cloud' and El Chichon aerosol layers are found above 30 km. A timescale of approximately 2 months between the appearance of the aerosol at 30.5 km and at 37.5 km is consistent with vertical transport of aerosol or vapor by eddy diffusion above 30 km. An anticorrelation exists between aerosol scattering and stratospheric temperatures. Periods of lower stratospheric temperatures may account for the formation of aerosol between 40 and 55 km altitude.

  5. Soil contamination with 90Sr in the near zone of the Chernobyl accident.

    PubMed

    Kashparov, V A; Lundin, S M; Khomutinin, Y V; Kaminsky, S P; Levchuk, S E; Protsak, V P; Kadygrib, A M; Zvarich, S I; Yoschenko, V I; Tschiersch, J

    2001-01-01

    Representative large-scale soil sampling on a regular grid of step width about 1 km was carried out for the first time in the near zone of the Chernobyl accident (radius 36 km). An integrated map of terrestrial 90Sr contamination density in the 30 km exclusion zone (scale 1:200,000) has been created from the analysed samples. Maps of the main agrochemical characteristics of the soils, which determine the fuel particle dissolution rates and the contamination of vegetation, were produced. The total contents of 90Sr on the ground surface of the 30 km zone in Ukraine (without the reactor site and the radioactive waste storages) was about 810 TBq (8.1 x 10(+14) Bq) in 1997, which corresponds to 0.4-0.5% of the Chernobyl reactor inventory at the time of the accident. This assessment is 3-4 times lower than previous estimates. PMID:11468820

  6. Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) scientific objectives

    NASA Astrophysics Data System (ADS)

    Riese, M.; Oelhaf, H.; Preusse, P.; Blank, J.; Ern, M.; Friedl-Vallon, F.; Fischer, H.; Guggenmoser, T.; Höpfner, M.; Hoor, P.; Kaufmann, M.; Orphal, J.; Plöger, F.; Spang, R.; Suminska-Ebersoldt, O.; Ungermann, J.; Vogel, B.; Woiwode, W.

    2014-07-01

    The upper troposphere/lower stratosphere (UTLS) represents an important part of the climate system. Even small changes in the composition and dynamic structure of this region have significant radiative effects. Quantifying the underlying physical and chemical processes therefore represents a crucial task. Currently, there is a lack of UTLS observations with sufficient three-dimensional resolution. The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) aircraft instrument addresses this observational lack by providing observations of numerous trace constituents as well as temperature and cloud structures with an unprecedented combination of vertical resolution (up to 300 m) and horizontal resolution (about 30 km × 30 km). As a result, important scientific questions concerning stratosphere-troposphere exchange, the occurrence of subvisible cirrus clouds in the lowermost stratosphere (LMS), polar chemistry, and gravity wave processes can be addressed, as reviewed in this paper.

  7. A cosmic dust influx model. III

    NASA Astrophysics Data System (ADS)

    Lebedinets, V. N.; Begkhanov, M.

    A model of cosmic dust influx is developed using results of radar and photographic studies of meteors and bolides, micrometeor impact data obtained during space missions, and the available experimental data on dust particles as small as 10 to the -17th g. It is shown, in particular, that particles of all sizes occurring above 30 km are mainly of meteor origin. Above 140 km, the earth atmosphere contains only primary cosmic particles of all sizes whose concentrations are equal to those observed in the interplanetary space but whose flux densities are twice as high. Above 30 km and below 100 km, the atmosphere contains primary micrometeor particles with masses less than 10 to the -8th g and particles of the same mass formed as a result of the fragmentation of large meteoric bodies.

  8. The Accidental Tide Gauge: A GPS Reflection Case Study from Kachemak Bay, Alaska

    NASA Technical Reports Server (NTRS)

    Larson, Kristine M.; Ray, Richard D.; Nievinski, Felipe G..; Freymueller, Jeffrey T.

    2013-01-01

    For the last decade, it has been known that reflected GPS signals observed with specialized instruments could be used to measure sea level. In this letter, data from an existing geodeticquality GPS site near Kachemak Bay, Alaska, are analyzed for a one-year time period. Daily sea-level variations are more than 7 m. Tidal coefficients have been estimated and compared with coefficients estimated from records from a traditional tide gauge at Seldovia Harbor, approximately 30 km away. The GPS and Seldovia estimates of M(sub 2) and S(sub 2) coefficients agree to better than 2%; much of this residual can be attributed to true differences in the tide over 30 km as it propagates up Kachemak Bay. For daily mean sea levels the agreement is 2.3 cm. Because a standard geodetic GPS receiver/antenna is used, this GPS instrument can measure long-term sea-level changes in a stable terrestrial reference frame.

  9. [LIFE QUALITY OF CHILDREN WITH SMALL ANOMALIES OF HEART DEVELOPMENT, BORN TO PARENTS IRRADIATED IN CHILDHOOD IN THE CHERNOBYL ACCIDENT].

    PubMed

    Kondrashova, V G; Dombrovskaya, N S

    2015-01-01

    The study involved 162 children with small anomalies of heart development (SAHD) in core group (children born to parents evacuated from the 30-km zone in childhood) and 39 children in the control group. Quality of life of adolescents was assessed by questionnaire MOS-SF-36 in the Russified version (changed by International reseach centre of life quality, Russia, St. Petersburg, 1998). In children of main group with SAHD, was established systemic pathological process involving not only the cardiovascular system, but also an autonomic nervous systems, hemostasis, upper gastro-intestinal tract, hepatobiliary, urinary system, musculoskeletal system and others, which causes polymorphic clinical picture. Quality of life in children with SAHD, born from parents evacuated from the 30-km Chernobyl zone in childhood was reduced in comparison with practically healthy children. The quality life reduction relate, primarily, physical functioning. Clinical polymorphism and reduced quality of life require the development of approaches to improve diagnosis, treatment and rehabilitation of these patients. PMID:26118021

  10. West Clearwater, Quebec impact structure. I - Field geology, structure and bulk chemistry. II - Petrology

    NASA Technical Reports Server (NTRS)

    Simonds, C. H.; Phinney, W. C.; Mcgee, P. E.; Cochran, A.

    1978-01-01

    A field study at the 30-km-diameter West Clearwater impact crater was carried out during the summer of 1977 to identify the nature of the flow of impact melt and less shocked debris during the excavation stage of the cratering process. The present paper investigates: (1) comparisons with other impact craters and lunar samples; (2) generation and emplacement mechanisms of impact melts and associated clastic debris; and (3) the geometry of the transient cavity and the pristine morphology of the crater.

  11. Distributed temperature sensing system using a commercial OTDR and a standard EDFA with controlled gain

    NASA Astrophysics Data System (ADS)

    Bassan, Fabio R.; Salgado, Felipe C.; Fruett, Fabiano; Rosolem, Joao B.

    2016-05-01

    The distributed temperature sensor system based in the spontaneous Raman backscattering is demonstrated for the first time to our knowledge, using a commercial OTDR (Optical Time Domain Reflectometer) and a standard erbium doped fiber amplifier (EDFA) with controlled gain. We evaluated this approach in a 30 km of single mode fiber using an OTDR pulse width of 100 ns and an EDFA with 17 dBm of output power.

  12. Detection of two satellites in the Cassini division of Saturn's rings

    NASA Technical Reports Server (NTRS)

    Marouf, E. A.; Tyler, G. L.

    1986-01-01

    The presence of two about 10-km-radius satellites within a 100-km-wide gap in the Cassini division of Saturn's rings is inferred from the observation of perturbations of nearby ring material. The perturbations are detected as regular fluctuations in the optical depth profile measured during Voyager radio occultation by the rings and are used to estimate the satellite's orbits and masses. The two satellites appear to 'shepherd' a 30-km-wide ringlet within the gap.

  13. A fully automated digitally controlled 30-inch telescope

    NASA Technical Reports Server (NTRS)

    Colgate, S. A.; Moore, E. P.; Carlson, R.

    1975-01-01

    A fully automated 30-inch (75-cm) telescope has been successfully designed and constructed from a military surplus Nike-Ajax radar mount. Novel features include: closed-loop operation between mountain telescope and campus computer 30 km apart via microwave link, a TV-type sensor which is photon shot-noise limited, a special lightweight primary mirror, and a stepping motor drive capable of slewing and settling one degree in one second or a radian in fifteen seconds.

  14. Extraction of Aerosol and Rayleigh Components from Doppler Lidar Return Signal

    NASA Technical Reports Server (NTRS)

    Barnes, John E.; Fischer, Ken W.; Abreu, Vincent J.; Skinner, Wilbert R.

    1992-01-01

    One of the most significant problems which limits the applicability of lidar systems for pressure and density profile measurements below 30 km altitude is the presence of atmospheric aerosols which contaminate the molecular or Rayleigh return signal. A new technique is described which allows for the separation of the return signal into aerosol and molecular scattered components. The technique was applied to data from the University of Michigan's High Resolution Doppler Lidar (HRDL).

  15. Mode-selective optical packet switching in mode-division multiplexing networks.

    PubMed

    Diamantopoulos, N P; Hayashi, M; Yoshida, Y; Maruta, A; Maruyama, R; Kuwaki, N; Takenaga, K; Uemura, H; Matsuo, S; Kitayama, K

    2015-09-01

    A novel mode-selective optical packet switching, based on mode-multiplexers/demultiplexers and multi-port optical micro-electro-mechanical systems (MEMS) switches, has been proposed and experimentally demonstrated. The experimental demonstration was performed using the LP(01), LP(11a) and LP(11b) modes of a 30-km long mode-division multiplexed few-mode fiber link, utilizing 40 Gb/s, 16-QAM signals. PMID:26368463

  16. Ground vibrations from heavy freight trains

    NASA Astrophysics Data System (ADS)

    Dawn, T. M.

    1983-03-01

    Ground vibration from heavy freight trains on good quality welded track are found to have only a weak dependence on train speed above 30 km/h. At the site on which these tests were carried out a critical speed was found at which the vibration reached a peak. The frequencies of vibration produced appear to be functions of track and vehicle dimensions and the critical speed occurs at the coincidence of sleeper passage frequency and the total vehicle on track resonance frequency.

  17. Cloud Layers East of the Great Red Spot

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This color view of the region just to the East of the Great Red Spot was taken by Voyager 1 on March 4, 1979 at a distance of 1,000,000 miles (1,800,000 km). Differences in cloud color may indicate relative heights of the cloud layers but the exact relationship between color and height has not yet been established. The smallest clouds seen in this picture are approximately 20 miles (30 km) across.

  18. Cloud Layers Southeast of the Great Red Spot

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This view of the region just to the Southeast of the Great Red Spot was taken by Voyager 1 on March 4, 1979 at a distance of 1,100,000 miles (1,800,000 km). Differences in cloud color may indicate relative heights of the cloud layers but the exact relationship between color and height has not yet been established. The smallest clouds seen in this picture are approximately 20 miles (30 km) across.

  19. The discrepancy between stratospheric ozone profiles from balloon soundings and from other techniques: A possible explanation

    NASA Technical Reports Server (NTRS)

    Demuer, Dirk; Debacker, Hugo

    1994-01-01

    Regular balloon ozone soundings with electrochemical sondes have been performed at Uccle since 1969. More than 450 ozone soundings between 1985 and 1989 were used to calculate the altitudes Zs from the VIZ radiosonde data and the altitudes Zr deduced from the tracking of the balloon train with a primary wind-finding radar. The values of Zs at fixed times appeared to be systematically too low as compared to Zr. The differences Zr-Zs increase with altitude; at 30 km the annual mean values of Zr-Zs (plus or minus standard deviation) vary between 590 plus or minus 910 m and 1410 plus or minus 1160 m, according to the pressure calibration of different manufacturing series of radiosondes. From these results it is found that around the 30 km level the ozone concentrations calculated from soundings with VIZ sondes are too low by 7.5 to 14 percent, depending upon the manufacturing series of radiosondes. At least part of the discrepancy which has often been found between ozone profiles from balloon soundings and from other techniques such as rocket observations or Umkehr measurements may be explained by this effect. An altitude correction would have important consequences as to the climatology of ozone in the middle stratosphere as adopted at the moment. About half of the day-to-day variability of ozone observed from soundings with VIZ radiosondes above the 30 km level, is induced by the variability of Zr-Zs. The agreement between altitudes calculated from radar data and Vaisala radiosondes is much better; from 34 comparative soundings a mean difference (plus or minus standard deviation) of about -300 plus/minus 180 m was found at 30 km.

  20. SAM II aerosol profile measurements, Poker Flat, Alaska; July 16-19, 1979

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Chu, W. P.; Mcmaster, L. R.; Grams, G. W.; Herman, B. M.; Pepin, T. J.; Russell, P. B.; Swissler, T. J.

    1981-01-01

    SAM II satellite measurements during the July 1979 Poker Flat mission, yielded an aerosol extinction coefficient of 0.0004/km at 1.0 micron wavelength, in the region of the stratospheric aerosol mixing ratio peak (12-16 km). The stratospheric aerosol optical depth for these data, calculated from the tropopause through 30 km, is approximately 0.001. These results are consistent with the average 1979 summertime values found throughout the Arctic.

  1. Iridium{reg_sign} worldwide personal communication system

    SciTech Connect

    Helm, J.

    1997-01-01

    The IRIDIUM system is a personal worldwide communication system designed to support portable, low power subscriber units through the use of a constellation of satellites in low earth polar orbit. The satellites are networked together to form a system which provides continuous line-of-sight communications between the IRIDIUM system and any point within 30 km of the earth{close_quote}s surface. The system architecture and operation are described. {copyright} {ital 1997 American Institute of Physics.}

  2. Intercomparison between ozone profiles measured above Spitsbergen by lidar and sonde techniques

    NASA Technical Reports Server (NTRS)

    Fabian, Rolf; Vondergathen, Peter; Ehlers, J.; Krueger, Bernd C.; Neuber, Roland; Beyerle, Georg

    1994-01-01

    This paper compares coincident ozone profile measurements by electrochemical sondes and lidar performed at Ny-Alesund/Spitsbergen. A detailed height dependent statistical analysis of the differences between these complementary methods was performed for the overlapping altitude region (13-35 km). The data set comprises ozone profile measurements conducted between Jan. 1989 and Jan. 1991. Differences of up to 25 percent were found above 30 km altitude.

  3. Strong refraction near the Venus surface - Effects observed by descent probes

    NASA Technical Reports Server (NTRS)

    Croft, T. A.

    1982-01-01

    The telemetry signals from Pioneer Venus probes indicated the strong downward refraction of radio waves. As the probes descended, the strength of the direct signal decreased because of absorption and refractive defocusing. During the last 30 km of descent there was a second measured component in addition to the direct signal. Strong atmospheric reaction is important in strengthening echoes that are scattered toward the earth. Such surface-reflected signals are good indicators of horizontal winds.

  4. Sizes and polycyclic aromatic hydrocarbon composition distributions of nano, ultrafine, fine, and coarse particulates emitted from a four-stroke motorcycle.

    PubMed

    Chien, Shu M; Huang, Yuh J

    2010-11-01

    Thus, this study was undertaken to determine the size distribution, concentration, species, and carcinogenic potency of particulate matter and particle-bound polycyclic aromatic hydrocarbons (PAHs) emitted from 4-st/mc at various speeds (idle, 15 km/h, 30 km/h). Approximately 80% of the particles emitted from the that is, they are primary inhalable particulates. The particle total number concentrations (TNCs) emitted while idling and at 15 and 30 km/h were 2.07 x 10⁴, 2.35 x 10⁴, and 2.60 x 10⁴ #/cm³, respectively; i.e., they increased at elevated speeds. Notably, most of the particles emitted at 30 km/h had diameters of less than 0.65 μm and contained higher percentages of total PAHs. Excluding incomplete combustion, we suspected that some of the lower-molecular-weight PAHs [phenanthrene (PA), anthracene (Ant), pyrene (Pyr)] obtained in the fine particles at idle originated from unburned 95-octane unleaded fuel. When operated at 15 km/h, pyrolysis of the PAHs dominated, resulting in increased amounts of medium-molecular-weight PAHs {fluorene (FL), Pyr, benz[a]anthracene (BaA), chrysene (CHR)} in the ultrafine particles. Furthermore, at 30 km/h, more pyrosynthesis products {benzo[a]pyrene (BaP), indeno[1,2,3,-cd]pyrene (IND), dibenz[a,h]anthracene (DBA)}, induced through combustion at the correspondingly higher temperature, were exhausted with the nanoparticles. Although the total concentrations of BaP-equivalent emissions were inconsistent with the total PAHs, the nanoscale-sized particulates emitted from the 4-st/mc at higher speeds had the strongest PAH-related carcinogenic potencies, which should be a great concern. PMID:20924922

  5. Field testing of commercially manufactured capture collars on white-tailed deer

    USGS Publications Warehouse

    Mech, L.D.; Kunkel, K.E.; Chapman, R.C.; Kreeger, T.J.

    1990-01-01

    We conducted 31 tests of commercially manufactured capture collars on female white-tailed deer (Odocoileus virginianus) in the Superior National Forest, Minnesota, under temperatures from -37C to 22C. Deer were recaptured in 28 of the 31 tests; in the 3 failures, we remotely released the collars from the deer. Communication with the collars was achieved from up to 3.0 km on the ground and 26.5 km from the air.

  6. Development of optical fiber frequency and time distribution systems

    NASA Technical Reports Server (NTRS)

    Lutes, G.

    1982-01-01

    The development of ultra stable optical fiber distribution systems for the dissemination of frequency and timing references is reported. The ultimate design goals for these systems are a frequency stability of 10 to the -17 power for tau or = 100 sec and time stability of + or - 0.1 ns for 1 year and operation over distances or = 30 km. A prototype system is reviewed and progress is discussed.

  7. Evaluation of Environmental Contamination and Estimated Radiation Doses for the Return to Residents’ Homes in Kawauchi Village, Fukushima Prefecture

    PubMed Central

    Taira, Yasuyuki; Hayashida, Naomi; Yamaguchi, Hitoshi; Yamashita, Shunichi; Endo, Yuukou; Takamura, Noboru

    2012-01-01

    To evaluate the environmental contamination and radiation exposure dose rates due to artificial radionuclides in Kawauchi Village, Fukushima Prefecture, the restricted area within a 30-km radius from the Fukushima Dai-ichi Nuclear Power Plant (FNPP), the concentrations of artificial radionuclides in soil samples, tree needles, and mushrooms were analyzed by gamma spectrometry. Nine months have passed since samples were collected on December 19 and 20, 2011, 9 months after the FNPP accident, and the prevalent dose-forming artificial radionuclides from all samples were 134Cs and 137Cs. The estimated external effective doses from soil samples were 0.42–7.2 µSv/h (3.7–63.0 mSv/y) within the 20-km radius from FNPP and 0.0011–0.38 µSv/h (0.010–3.3 mSv/y) within the 20–30 km radius from FNPP. The present study revealed that current levels are sufficiently decreasing in Kawauchi Village, especially in areas within the 20- to 30-km radius from FNPP. Thus, residents may return their homes with long-term follow-up of the environmental monitoring and countermeasures such as decontamination and restrictions of the intake of foods for reducing unnecessary exposure. The case of Kawauchi Village will be the first model for the return to residents’ homes after the FNPP accident. PMID:23049869

  8. Evaluation of environmental contamination and estimated radiation doses for the return to residents' homes in Kawauchi Village, Fukushima prefecture.

    PubMed

    Taira, Yasuyuki; Hayashida, Naomi; Yamaguchi, Hitoshi; Yamashita, Shunichi; Endo, Yuukou; Takamura, Noboru

    2012-01-01

    To evaluate the environmental contamination and radiation exposure dose rates due to artificial radionuclides in Kawauchi Village, Fukushima Prefecture, the restricted area within a 30-km radius from the Fukushima Dai-ichi Nuclear Power Plant (FNPP), the concentrations of artificial radionuclides in soil samples, tree needles, and mushrooms were analyzed by gamma spectrometry. Nine months have passed since samples were collected on December 19 and 20, 2011, 9 months after the FNPP accident, and the prevalent dose-forming artificial radionuclides from all samples were (134)Cs and (137)Cs. The estimated external effective doses from soil samples were 0.42-7.2 µSv/h (3.7-63.0 mSv/y) within the 20-km radius from FNPP and 0.0011-0.38 µSv/h (0.010-3.3 mSv/y) within the 20-30 km radius from FNPP. The present study revealed that current levels are sufficiently decreasing in Kawauchi Village, especially in areas within the 20- to 30-km radius from FNPP. Thus, residents may return their homes with long-term follow-up of the environmental monitoring and countermeasures such as decontamination and restrictions of the intake of foods for reducing unnecessary exposure. The case of Kawauchi Village will be the first model for the return to residents' homes after the FNPP accident. PMID:23049869

  9. Near-field strain observations of the October 2013 Ruisui, Taiwan, earthquake: source parameters and limits of very short-term strain detection

    NASA Astrophysics Data System (ADS)

    Canitano, Alexandre; Hsu, Ya-Ju; Lee, Hsin-Ming; Linde, Alan T.; Sacks, Selwyn

    2015-08-01

    Volumetric strain changes associated with the October 2013 M w 6.2 Ruisui earthquake were recorded by a network made up with four borehole Sacks-Evertson dilatometers in eastern Taiwan. These instruments are located within 25-30 km of the seismic source providing also high-resolution near-field observations. Co-seismic offsets larger than a few 102 n ɛ were seen by most of the sensors. We relocated the 30 km × 30 km fault plane through a grid-search approach. The inferred fault parameters (217°, 48°, 49°) are in reasonable agreement with those resulting from the inversions of long-period seismic waves (209°, 59°, 50°) as well as from GPS data inversion (200°, 45°, 42°). Moreover, analysis of the 100-Hz sampling data 10 s before seismic radiations indicate no pre-seismic strain change emergent from the instrumental noise level (from 10 -2 to 10 -1 n ɛ). Such an observation sets limits on any precursory change in a nucleation area, taken to have dimensions of about 250-300 m, seconds before the mainshock. Thus, the upper limit of any pre-seismic moment is about 10 -5 % of the total seismic moment of the Ruisui earthquake.

  10. Multiple-Aperture Based Solar Seeing Profiler

    NASA Astrophysics Data System (ADS)

    Zhao, Gang; Ren, Deqing

    2015-08-01

    Characterization of daytime atmospheric turbulence profile up to 30 km above the telescope is crucial for designs and performance estimations of solar Multi-Conjugate Adaptive Optics (MCAO) systems. To measure seeing profiles up to 30km, we introduce the Multiple Aperture Seeing Profiler (MASP). It bases on the principle of S-DIMM+ and consists of two portable small telescopes similar to SHABAR. Thus the MASP take the advantages of both S-DIMM+ and SHABAR. It is portable and can be used without big telescope, while it has ability to measure turbulence profile up to 30km. Numerical simulations are carried out to evaluate the performance of MASP. We find that for one layer case, MASP can retrieve the seeing with error ~5% using 800 frames of WFS data, which is quite similar with the results of a telescope with diameter of 1120mm. We also simulate profiles with four turbulence layers, and find that our MASP can well retrieve the strengths and heights of the four turbulence layers. Since previous measurements at BBSO showed that daytime turbulence profile typically consists of four layers, MASP we introduced is sufficient for actual seeing measurement.

  11. Lithospheric thinning associated with rifting in East Africa

    NASA Technical Reports Server (NTRS)

    Wendlandt, R. F.; Morgan, R.

    1982-01-01

    The rate of ascent of the thermal perturbation of eruptive rock types in the Kenya Dome region can be calculated for depths of origin ranging from greater than 170 km to the lower crust (25-30 km) as combined with dated occurrences. An equation is derived and solved iteratively for ascent velocity at 10 km depth intervals from 150-30 km, assuming a thermal diffusivity of 1 sq mm/sec. For radii of 50 and 100 km and constant gradient increases within the range 55-60 C/km over the lithosphere-asthenosphere boundary (LAB) ascent depth range, the calculated rate of upwelling corresponds well with the results of a simple thermal model of lithospheric thinning. A 1 C/km change in gradient results approximately in a 0.55 Myr change in ascent time from 150 to 30 km, due to the increasing differential between the geotherm and the solidus with decreasing depths and the increasing rate of heat loss to the surface. It is suggested by the temporal-spatial-compositional relations of eruptives in the Kenya Dome region that there is a shallowing of magma source regions with time, implying encroachment of a thermal anomaly.

  12. The effect of increased carbon dioxide concentrations on stratospheric ozone

    NASA Technical Reports Server (NTRS)

    Boughner, R. E.

    1978-01-01

    Consideration is given to the influence on ozone of an increased carbon dioxide concentration, for which a measurable growth has been observed in the recent past. Increased carbon dioxide can indirectly affect ozone by perturbing atmospheric temperatures, which will alter ozone production, whose rate displays a fairly strong temperature dependence. This paper presents one-dimensional model results for the steady state ozone behavior when the CO2 concentration is twice its ambient level; the results account for coupling between chemistry and temperature. When the CO2 level doubled, the total ozone burden increased in relation to the ambient burden by 1.2-2.5%, depending on the vertical diffusion coefficient used. Above 30 km, ozone concentrations were larger than the ambient values, a maximum increase of 16% being reached at 43 km. In this region the relative variations were insensitive to the choice of diffusion coefficient. Below 30 km, ozone concentrations were smaller than the unperturbed values and were sensitive to the vertical diffusion profile in this region (10-30 km).

  13. Accuracy estimates for some global analytical models of the Earth's main magnetic field on the basis of data on gradient magnetic surveys at stratospheric balloons

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Yu. P.; Brekhov, O. M.; Bondar, T. N.; Filippov, S. V.; Petrov, V. G.; Tsvetkova, N. M.; Frunze, A. Kh.

    2014-03-01

    Two global analytical models of the main magnetic field of the Earth (MFE) have been used to determine their potential in deriving an anomalous MFE from balloon magnetic surveys conducted at altitudes of ˜30 km. The daily mean spherical harmonic model (DMSHM) constructed from satellite data on the day of balloon magnetic surveys was analyzed. This model for the day of magnetic surveys was shown to be almost free of errors associated with secular variations and can be recommended for deriving an anomalous MFE. The error of the enhanced magnetic model (EMM) was estimated depending on the number of harmonics used in the model. The model limited by the first 13 harmonics was shown to be able to lead to errors in the main MFE of around 15 nT. The EMM developed to n = m = 720 and constructed on the basis of satellite and ground-based magnetic data fails to adequately simulate the anomalous MFE at altitudes of 30 km. To construct a representative model developed to m = n = 720, ground-based magnetic data should be replaced by data of balloon magnetic surveys for altitudes of ˜30 km. The results of investigations were confirmed by a balloon experiment conducted by Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation of the Russian Academy of Sciences and the Moscow Aviation Institute.

  14. Variation of the lunar highland surface roughness at baseline 0.15-100 km and the relationship to relative age

    NASA Astrophysics Data System (ADS)

    Yokota, Y.; Gwinner, K.; Oberst, J.; Haruyama, J.; Matsunaga, T.; Morota, T.; Noda, H.; Araki, H.; Ohtake, M.; Yamamoto, S.; Gläser, P.; Ishihara, Y.; Honda, C.; Hirata, N.; Demura, H.

    2014-03-01

    We report the surface roughness analysis of the lunar highlands for the baseline range 0.15-100 km. We use the Median Differential Slope αm to investigate the scale dependency of the roughness and derive the global αm distribution from SELENE Laser Altimeter and Terrain Camera data. While αm(l) versus baseline l (km) plots vary among different highland types, all highlands commonly show a peak at 3-30 km. The Pre-Nectarian surface shows a relatively large αm(20-30 km). Our analysis is supported by the simulation of synthetic surface cratering models and crater statistics. In our simulation, a peak of αm(30 km) is successfully reproduced. The actual crater density shows good correlation with an empirical roughness indicator. However, a large part of the Nectarian surface shows a peak at 6-9 km baseline. This peak may be caused by secondary craters and ejecta deposit textures from the Nectarian system basins.

  15. Vibronic Emission Spectroscopy of Benzyl-Type Radicals Generated by Corona Discharge

    NASA Astrophysics Data System (ADS)

    Yi, Eun Hye; Yoon, Young; Lee, Sang

    2014-06-01

    Benzyl radical is a prototypical aromatic free radical and has been the subject of numerous spectroscopic studies. On the other hand, ring-substituted benzyl radicals, benzyl-type radicals, have received less attention due to the difficulties associated with production in corona discharge and analysis of spectra. We report vibronic emission spectra of hetero halogen multi-substituted benzyl radicals generated by corona discharge of corresponding toluene derivatives using a pinhole-type glass nozzle, from which visible vibronic emission spectra were recorded using a long-path monochromator. The spectra show nice features of strongest origin band and a series of vibronic bands in the lower energies originating from the vibrationless D_1 state. From the analysis of the spectra observed, we determined the energies of the D_1 → D_0 electronic transition and vibrational mode frequencies in the ground electronic state. On the other hand, all substituted benzyl radicals show the origin bands shifted to red region with respect to the parental benzyl radical at 22002 cm-1. The shifts of multi-substituted benzyl radicals can be well estimated using the method developed from mono-substituted benzyl radicals as well as the positions of nodal point and mutual orientation of substituents, which could be useful for scientists to set a proper scanning range of their spectrometers for the spectroscopic observation of transient molecules. In this presentation, we will discuss the substituent effect on electronic transition energy and the experimental technique developed in this laboratory. Y. W. Yoon and S. K. Lee, J. Phys. Chem. A, 117, 2485 (2013). Y. W. Yoon, S. Y. Chae, and S. K. Lee, Chem. Phys. Lett., 584, 37 (2013). Y. W. Yoon and S. K. Lee, Chem. Phys. Lett., 570, 29 (2013).

  16. Structural domain walls in polar hexagonal manganites

    NASA Astrophysics Data System (ADS)

    Kumagai, Yu

    2014-03-01

    The domain structure in the multiferroic hexagonal manganites is currently intensely investigated, motivated by the observation of intriguing sixfold topological defects at their meeting points [Choi, T. et al,. Nature Mater. 9, 253 (2010).] and nanoscale electrical conductivity at the domain walls [Wu, W. et al., Phys. Rev. Lett. 108, 077203 (2012).; Meier, D. et al., Nature Mater. 11, 284 (2012).], as well as reports of coupling between ferroelectricity, magnetism and structural antiphase domains [Geng, Y. et al., Nano Lett. 12, 6055 (2012).]. The detailed structure of the domain walls, as well as the origin of such couplings, however, was previously not fully understood. In the present study, we have used first-principles density functional theory to calculate the structure and properties of the low-energy structural domain walls in the hexagonal manganites [Kumagai, Y. and Spaldin, N. A., Nature Commun. 4, 1540 (2013).]. We find that the lowest energy domain walls are atomically sharp, with {210}orientation, explaining the orientation of recently observed stripe domains and suggesting their topological protection [Chae, S. C. et al., Phys. Rev. Lett. 108, 167603 (2012).]. We also explain why ferroelectric domain walls are always simultaneously antiphase walls, propose a mechanism for ferroelectric switching through domain-wall motion, and suggest an atomistic structure for the cores of the sixfold topological defects. This work was supported by ETH Zurich, the European Research Council FP7 Advanced Grants program me (grant number 291151), the JSPS Postdoctoral Fellowships for Research Abroad, and the MEXT Elements Strategy Initiative to Form Core Research Center TIES.

  17. Light emitting transistors: A new route for display pixels (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Namdas, Ebinazar B.

    2015-10-01

    Organic light emitting transistors (LEFETs) are an emerging class of light emitting devices that have been successfully demonstrated in single-layer [1] and mutli-layer device structures [2]. LEFETs can simultaneously execute light-emission and standard logic functions (ON/OFF) of a transistor in a single device architecture [1]. This dual functionality of LEFETs has a potential to offer a new route to simplify fabrication of display pixels. However, the key problem of existing LEFETs thus far has been their low external quantum efficiency (EQE) at high brightness, poor ON/OFF ratio, and mobility. More recently, hybrid light emitting transistors [3-4], consisting of solution processed n-type metal oxide (inorganic) as the charge transport layer and light emitting conjugated polymer (organic), have been used to achieve higher mobility, ON/OFF ratio and brightness. In this talk, I will discuss the various factors that currently influence device performance in LEFETs, and will provide insights into our recent progress in developing high-performance hybrid LEFETs. References: (1). E. B. Namdas, J. S. Swensen, P. Ledochowitsch, J. D. Yuen, D. Moses, A. J. Heeger, Adv. Mater.,20, 1321 (2008). (2). M. Ullah, K. Tandy, S. D. Yambem, M. Aljada, P. L. Burn, P. Meredith, E. B. Namdas. Adv. Mater. 25, 6213-6218 (2013). (3). B. Walker, M. Ullah, G. J. Chae, P. L Burn, S. Cho, J. Y. Kim, E. B. Namdas, J. H. Seo. Appl Phys Lett, 105, 183302 (2014). (4). K. Muhieddine, M. Ullah, B. N. Pal, P. Burn, E. B. Namdas, Adv. Mater. 26, 6410 (2014).

  18. High grain, low noise organic and nanoelectronic photodetectors (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Huang, Jinsong

    2015-08-01

    The dramatically reduction of cost of photodetectors without comprising their performance will enable new applications in many fields. In this talk, I will brief our progress in the development of sensitive photodetectors/photon counters using low-cost solution processable organic and nano-electronic materials. Four types of device structures will be compared in terms of device gain, noise, sensitivity, response speed and linear dynamic range: 1) traditional diode structure, 2) a structure combine the photodiode and photoconductor through the interface trap triggered secondary charge injection, 3) an organic phototransistor that has combined photoconductive gain and photovoltaic gain, and 4) quantum dots modulated transistor channel conductance. Broad response spectrum from UV to NIR will be demonstrated, and active material limited performance will be discussed. Solution-Processed Nanoparticle Super-Float-Gated Organic Field-Effect Transistor as Un-cooled Ultraviolet and Infrared Photon Counter Yongbo Yuan, Qingfeng Dong, Bin Yang, Fawen Guo, Qi Zhang, Ming Han, and Jinsong Huang*, Scientific Reports, 3, 2707 (2013) A nanocomposite ultraviolet photodetector enabled by interfacial trap-controlled charge injection Fawen Guo, Bin Yang, Yongbo Yuan, Zhengguo Xiao, Qingfeng Dong, Yu Bi, and Jinsong Huang*, Nature Nanotechnology, 7, 798-802, (2012) Large Gain, Low Noise Nanocomposite Ultraviolet Photodetectors with a Linear Dynamic Range of 120 dB Yanjun Fang, Fawen Guo,Zhengguo Xiao, Jinsong Huang*, Advanced Optical Materials, 348-353 (2014) High Gain and Low-Driving-Voltage Photodetectors Based on Organolead Triiodide Perovskites Rui Dong, Yanjun Fang, Jungseok Chae, Jun Dai, Zhengguo Xiao, Qingfeng Dong,Yongbo Yuan, Andrea Centrone,Xiao Cheng Zeng , Jinsong Huang*. ,Advanced Materials, 2015

  19. Time Evolution of Coronal Magnetic Helicity in the Flaring Active Region NOAA 10930

    NASA Astrophysics Data System (ADS)

    Park, Sung-Hong; Jing, J.; Wang, H.

    2010-05-01

    To study the three-dimensional (3D) magnetic field topology and its long-term (a few days) evolution associated with the X3.4 flare of 2006 December 13, we investigate the temporal evolution of the relative coronal magnetic helicity in NOAA active region (AR) 10930 during the time period of December 8, 21:20 UT through December 14, 5:00 UT. The coronal helicity is calculated based on the 3D nonlinear force-free (NLFF) magnetic fields reconstructed by the optimization method (Wheatland et al. 2000) as implemented by Wiegelmann (2004). As the boundary conditions for the force-free reconstruction, we use the preprocessed Hinode Spectropolarimeter (SP) vector magnetograms in which the net Lorentz force and the torque in the photosphere are minimized (see Wiegelmann et al. 2006 for the details). The major findings of this study are: (1) a negative (left-handed) helicity of -5×1043 Mx2 in the AR corona is estimated right before the X3.4 flare; (2) the major flare is preceded by a significantly and consistently large amount of negative helicity injection (-2×1043 Mx2) into the corona over 2 days; (3) the temporal variation of helicity is comparable to that of the rotational speed in the southern sunspot with positive polarity; (4) in general, the time profile of the coronal helicity is well-matched with that of the helicity accumulation by the time integration of the simplified helicity injection rate (Chae 2001) determined by using SOHO MDI magnetograms; (5) at the time period of the channel structure development (December 11, 4:00-8:00 UT) with newly emerging flux and just right before the C5.7 class flare, the time variation of the coronal helicity shows a rapid and huge increase of negative helicity, but that of the helicity accumulation by MDI magnetograms indicates a monotonous increase of negative helicity.

  20. Evaluation of tropical channel refinement using MPAS-A aquaplanet simulations

    SciTech Connect

    Martini, Matus N.; Gustafson, Jr., William I.; O'Brien, Travis A.; Ma, Po -Lun

    2015-09-13

    Climate models with variable-resolution grids offer a computationally less expensive way to provide more detailed information at regional scales and increased accuracy for processes that cannot be resolved by a coarser grid. This study uses the Model for Prediction Across Scales–Atmosphere (MPAS22A), consisting of a nonhydrostatic dynamical core and a subset of Advanced Research Weather Research and Forecasting (ARW-WRF) model atmospheric physics that have been modified to include the Community Atmosphere Model version 5 (CAM5) cloud fraction parameterization, to investigate the potential benefits of using increased resolution in an tropical channel. The simulations are performed with an idealized aquaplanet configuration using two quasi-uniform grids, with 30 km and 240 km grid spacing, and two variable-resolution grids spanning the same grid spacing range; one with a narrow (20°S–20°N) and one with a wide (30°S–30°N) tropical channel refinement. Results show that increasing resolution in the tropics impacts both the tropical and extratropical circulation. Compared to the quasi-uniform coarse grid, the narrow-channel simulation exhibits stronger updrafts in the Ferrel cell as well as in the middle of the upward branch of the Hadley cell. The wider tropical channel has a closer correspondence to the 30 km quasi-uniform simulation. However, the total atmospheric poleward energy transports are similar in all simulations. The largest differences are in the low-level cloudiness. The refined channel simulations show improved tropical and extratropical precipitation relative to the global 240 km simulation when compared to the global 30 km simulation. All simulations have a single ITCZ. Furthermore, the relatively small differences in mean global and tropical precipitation rates among the simulations are a promising result, and the evidence points to the tropical channel being an effective method for avoiding the extraneous numerical artifacts seen in earlier

  1. Validation of three different scientific ozone products retrieved from IASI spectra using ozonesondes

    NASA Astrophysics Data System (ADS)

    Dufour, G.; Eremenko, M.; Griesfeller, A.; Barret, B.; Leflochmoën, E.; Clerbaux, C.; Hadji-Lazaro, J.; Coheur, P.-F.; Hurtmans, D.

    2011-08-01

    Three scientific ozone products from the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A, retrieved in three different research teams (LA, LATMOS/ULB, LISA) with different retrieval schemes, are characterized and validated using ozonesondes measurements. The three products are mature enough to be used for detailed analyses of atmospheric chemistry and transport in the troposphere. The characteristics of the products are analyzed in terms of retrieval sensitivity, systematic and random errors, and ability to retrieve the natural variability of ozone and focus on different partial columns from the lower troposphere up to 30 km. The validation covers the midlatitudes and the tropics and the period from January to December 2008. The products present degrees of freedom (DOF) in the troposphere between 1 and 1.2 on average in the midlatitudes and between 1 and 1.4 in the tropics. The DOF are distributed differently on the vertical depending on the profiles and the season: summer leading to a better sensitivity to the lower troposphere, as expected. The error estimates range between 10 and 20 % from the lower tropospheric partial columns (0-6 km and 0-8 km for the midlatitudes and the tropics respectively) to the UTLS partial columns (8-16 km and 11-20 km for the midlatitudes and the tropics respectively) for all the products and are about 5 % in the stratosphere (16-30 km) and for the column up to 30 km. The main feature that arises from the comparison with the ozonesondes is a systematic overestimation of ozone in the UTLS (between 10 and 25 %) by the three products in the midlatitudes and the tropics, attributed to the moderate vertical resolution of IASI and possibly to spectroscopic inconsistencies. The ability of the products to reproduce natural variability of tropospheric ozone is fairly good and depends on the considered season and region.

  2. Comparative studies of lunar, Martian, and Mercurian craters and plains

    NASA Technical Reports Server (NTRS)

    Oberbeck, V. R.; Arvidson, R. E.; Aggarwal, H. R.

    1975-01-01

    The spatial distribution of lunar smooth plains is not consistent with experimental simulations of melt rock emplacement during cratering in layered materials. Nor is it consistent with the location of melt rocks (suevite) near the Ries basin. Lunar smooth plains surrounding Imbrium are most extensive in areas where pre-existing craters are most degraded. This observation suggests that plains form by impact of basin and local primary crater ejecta, together with deposition of debris excavated by the resultant secondary cratering events. Craters within the belt of smooth plains surrounding the Caloris basin on Mercury are most degraded nearest the basin; this suggests that Mercurian smooth plains must, at least in part, be emplaced in a manner similar to plains surrounding the Imbrium basin. Mercurian uplands have a primary crater population deficient in small crater diameters (less than approximately 30 km). Lunar uplands far from major basins also have a crater population deficient in small crater sizes. Martian cratered terrain exhibits a similar crater deficiency, which was previously interpreted as due to obliteration of small craters (less than approximately 30 km) by some surface process. A crater size distribution deficient in small sizes (less than approximately 30 km) on the Mercurian, lunar, and Martian uplands has implications for the origin of debris bombarding the inner solar system during the period recorded by these surfaces. It is proposed that during late heavy bombardment, the inner solar system was inundated with bodies that broke up under tidal fission as they approached the planets. Such a mechanism would lend to production of a crater population deficient in small crater sizes, and it would also explain the large degree of spatial clustering of primary craters on Mercury, the moon, and Mars.

  3. First Rosetta Radio Science Bistatic Radar Observations of 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Andert, Thomas P.; Remus, Stefan; Simpson, Richard A.; Pätzold, Martin; Asmar, Sami W.; Kahan, Daniel S.; Bird, Mike K.; Häusler, Bernd; Tellmann, Silvia

    2015-04-01

    The Rosetta spacecraft was successfully inserted on 6th August 2014 into orbit around comet 67P/Churyumov-Gerasimenko. In September Rosetta was placed into bound orbits with an initial distance of 30 km and a decreasing distance until the end October. After lander delivery, bound orbits were maintained again at 20 km and 30 km. One of the objectives of the Rosetta Radio Science Investigations (RSI) is to address the dielectric properties, small-scale roughness, and rotational state of the nucleus of the comet, which can be determined by means of a surface scattering experiment, also known as Bistatic Radar. The radio subsystem transmitter located on board the Rosetta spacecraft beams right circularly polarized radio signals at two wavelengths -3.6 cm (X-Band) and 13 cm (S-Band) - toward the nucleus surface. Part of the impinging radiation is then scattered toward a receiver at a ground station on Earth and recorded. On September 29th, 2014 the first Bistatic Radar experiment ever at a comet was successfully conducted. The distance between 67P/Churyumov-Gerasimenko and Rosetta was 20 km and both right circularly polarized (RCP) and left circularly polarized (LCP) reflected signals from the comet's surface in X-Band were detected during the experiment at the Goldstone complex of the NASA Deep Space Network. The ultra-stable oscillator (USO) on board Rosetta served during the experiment as a very stable reference frequency source. The direct and reflected signal were separated during the experiment by only a fraction of 1 Hz. The extreme stability of the USO allowed a detection and separation of the weak signals even on the required long integration times. Five additional Bistatic Radar experiments were conducted successfully between mid-October and mid-December 2014 with the 70-m DSN ground stations in Goldstone and Canberra at different distances to the comet (10 km, 20 km and 30 km) and reflected signals were observed in each case.

  4. Territory contamination with the radionuclides representing the fuel component of Chernobyl fallout.

    PubMed

    Kashparov, V A; Lundin, S M; Zvarych, S I; Yoshchenko, V I; Levchuk, S E; Khomutinin, Y V; Maloshtan, I M; Protsak, V P

    2003-12-30

    The data obtained through a series of experiments were used to specify the correlation of activities of the fuel component radionuclides of Chernobyl fallout and to create the maps of the 30-km Chernobyl zone terrestrial density of contamination with 154Eu, 238Pu, 239+240Pu and 241Am (on 01.01.2000). In the year 2000, total inventories of the fuel component radionuclides in the upper 30-cm soil layer of the 30-km Chernobyl zone in Ukraine (outside the ChNPP industrial site, excluding the activity located in the radioactive waste storages and in the cooling pond) were estimated as: 90Sr--7.7 x 10(14) Bq; 137Cs--2.8 x 10(15) Bq; 154Eu--1.4 x 10(13) Bq; 238Pu--7.2 x 10(12) Bq; 239+240Pu--1.5 x 10(13) Bq; 241Am--1.8 x 10(13) Bq. These values correspond to 0.4-0.5% of their amounts in the ChNPP unit 4 at the moment of the accident. The current estimate is 3 times lower than the previous widely-cited estimates. Inventories of the fuel component radionuclides were also estimated in other objects within the 30-km zone and outside it. This allowed more accurate data to be obtained on the magnitude of a relative release of radionuclides in the fuel particles (FP) matrix during the Chernobyl accident outside the ChNPP industrial site. It amounts to 1.5+/-0.5% of these radionuclides in the reactor, which is 2 times lower than the previous estimates. Two-thirds of the radionuclides release in the FP was deposited on the territory of Ukraine. PMID:14630415

  5. Crustal structure along the geosciences transect from Altay to Altun Tagh

    USGS Publications Warehouse

    Wang, Y.-X.; Han, G.-H.; Jiang, M.; Yuan, X.-C.; Mooney, W.D.; Coleman, R.G.

    2004-01-01

    Based upon the P- and S-wave data acquired along the geoscience transect from Altay to Altun Tagh in Northwest China, the crustal structures of velocities and Poisson's ratio are determined. The crustal velocity structure features an obvious three-layer structure with velocities of 6. 0 ??? 6. 3km/s, 6. 3 ??? 6. 6km/s and 6.9 ??? 7. Okm/s from surface to depth, respectively. The crustal thickness along the. entire profile is mostly 50km with the thickest crust (56km) beneath the Altay and the thinnest (46km) beneath the Junggar basin. The velocities underlying Moho are 7.7 to 7.8km/s between the Tianshan and the Junggar basin, and 7.9 to 8.0km/s below the Altay Mountains and eastern margin of the Tarim basin. The southern half of the profile, including the eastern Tianshan Mountains and eastern margin of the Tarim basin, shows low P-wave velocities and ?? = 0. 25 to a depth, of 30km, which suggests a quartz-rich, granitic upper crustal composition. The northern half of the profile below the Altay Mountains and Junggar Accretional Belt has a higher Poisson's ratio of ?? = 0.26 ??? 0.27 to a depth of 30km, indicative of an intermediate crustal composition, The entire profile is underlain by a 15 to 30km thick high-velocity (6.9 ??? 7.0km/s; ?? = 0. 26 - 0.28) lower crustal layer that we interpret to have a bulk composition of mafic granulite. At the southern end of the profile a 5km-thick midcrustal low-velocity layer ( Vp, = 5.9km/s, ?? = 0.25) underlies the Tianshan and the region to the south, and may be indicative of granitic intrusive in Late Paleozoic.

  6. Crustal Structure of Northeastern Sicily, South Italy, From Tomographic Inversion of Local Earthquake Arrival-times

    NASA Astrophysics Data System (ADS)

    Orecchio, B.; Aloisi, M.; Barberi, G.; Neri, G.

    After integrating the databases of the local and national seismic networks relative to lithospheric seismicity that occurred in and around Northeastern Sicily bet ween 1978 and 2001, we selected 932 events for 3D local tomography of P- and S-wave velocity. A dataset of 10241 P and 5597 S arrival times was inverted for Vp, Vs and hypocenter distributions using the SIMULPS12 algorithm. Analysis of the Derivative Weight Sum and Spread Function detected a rather good level of constraint of velocity at nodes of a grid with horizontal and vertical spacing of 10 and 6 km respectively, spanning the upper 30 Km beneath the area including Central and Northeastern Sicily, Southern Calabria and the Southeasternmost Tyrrhenian Sea. Standard deviation of arrival-time residuals after 3D inversion was about 20% lower than obtained by locating the same earthquakes using the minimum 1D model. Four main spatial domains can be distinguished in the obtained velocity structure: i) a high-velocity domain corresponding to Tyrrhenian structural units; ii) low-velocity domain corresponding to Sicilian units; iii) a domain corresponding to the Calabrian Arc characterized by positive velocity anomalies at shallow depth (nodes in the range 0-12 Km) and by negative velocity ones below (18-30 Km); iv) positive anomalies at deep nodes (18-30 Km) and negative anomalies above, in the area including the Etna volcano and the Ionian coast of Sicily near the volcanic edifice. Velocity distributions were analyzed jointly with the geophysical and geological information available in the literature in order to improve our knowledge of the crustal structure in the study area. Furthermore, comparisons were made with the most recent regional geodynamic models and led us to state that the crustal features evidenced in the present investigation match well with the model assuming gravity- induced southeastward roll-back of an Ionian lithospheric slab subducting beneath the Tyrrhenian sea.

  7. ASSESSING THE MERCURY HEALTH RISKS ASSOCIATED WITH COAL-FIRED POWER PLANTS: ISSUES IN ATMOSPHERIC PROCESSES.

    SciTech Connect

    LIPFERT, F.; SULLIVAN, T.; RENNINGER, S.

    2004-03-28

    The rationale for regulating air emissions of mercury from U.S. coal-fired power plants largely depends on mathematical dispersion modeling, including the atmospheric chemistry processes that affect the partitioning of Hg emissions into elemental (Hg{sub 0}) and the reactive (RGM) forms that may deposit more rapidly near sources. This paper considers and evaluates the empirical support for this paradigm. We consider the extant experimental data at three spatial scales: local (< 30 km), regional (< {approx}300 km), and national (multi-state data). An additional issue involves the finding of excess Hg levels in urban areas.

  8. Estimation of Interplate Coupling in the Central and Eastern of Java trench from CGPS Observation

    NASA Astrophysics Data System (ADS)

    Irwan, Meilano; Endra, Gunawan; Susilo, Susilo; Joni, Effendi; Hasanuddin Z., Abidin; Dina, Sarsito

    2015-04-01

    We used three-component surface velocities in the Central and Eastern Java to estimate plate coupling on the subduction interface at the Java subduction zone. The observation period starting from 2009 to 2013 with more than 40 CGPS observation stations. The results show a heterogeneous distribution of interplate coupling from Central to the East of Java trench. Strong coupling at a depth of 10-30 km with rate 3-4 cm/yr is estimated at the south of East Java. The downdip limits of the coupled areas is estimated at 50km. This slip deficit on subduction interface has important implication for seismic hazard of Java Island.

  9. Ganges Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This Mars Global Surveyor (MGS) Orbiter Camera (MOC) image shows a high resolution view of portions of the lobes of several landslide deposits in Ganges Chasma. Dark material near the bottom (south) end of the image is windblown sand.

    Location near: 8.2oS, 44.3oW Image width: 3.0 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  10. The 1980 stratospheric-tropospheric exchange experiment

    NASA Technical Reports Server (NTRS)

    Margozzi, A. P. (Editor)

    1983-01-01

    Data are presented from the Stratospheric-Tropospheric Water Vapor Exchange Experiment. Measurements were made during 11 flights of the NASA U-2 aircraft which provided data from horizontal traverser and samplings in and about the tops of extensive cirrus-anvil clouds produced by overshooting cumulus turrets. Aircraft measurements were made of water vapor, ozone, ambient and cloud top temperature, fluorocarbons, nitrous oxide, nitric acid, aerosols, and ice crystal populations. Balloonsondes were flown about twice daily providing data on ozone, wind fields, pressure and temperature to altitudes near 30 km. Satellite photography provided detailed cloud and cloud top temperature information. Descriptions of individual experiments and detailed compilations of all results are provided.

  11. The BLISS measurements of NO2 - Some new insights

    NASA Technical Reports Server (NTRS)

    Pyle, J. A.; Webster, C. R.; May, R. D.; Lary, D. J.

    1991-01-01

    The present study compares the diurnal variation of NO2 measured near 30 km by the BLISS in situ laser spectrometer with calculations from a photochemical model that includes a detailed description of multiple scattering. Even better agreement is found between the data and the model, both at sunset and during the day. The conclusions of an earlier study that the high-resolution in situ measurements of NO2 facilitated validation of the understanding of the diurnal chemistry of NO2 are confirmed.

  12. Composition and stability of coyote families and territories in North Dakota

    USGS Publications Warehouse

    Allen, S.H.; Hastings, J.O.; Kohn, S.C.

    1987-01-01

    Coyote (Canis latrans) families studied in North Dakota during 1976 to 1978 contained three or more adults during the spring-summer season, and they occupied large contiguous, non-overlapping territories. Coyote territories averaged 61 km2 during the spring-summer season and 30 km2 during fall-winter season. Three of four families occupied territories that were similar in size for two consecutive years; however, boundaries changed within individual families when one or both alpha adults were killed. All coyotes replacing dead alpha adults were 1 year old.

  13. An energy-efficient and elastic optical multiple access system based on coherent interleaved frequency division multiple access.

    PubMed

    Yoshida, Yuki; Maruta, Akihiro; Ishii, Kenji; Akiyama, Yuji; Yoshida, Tsuyoshi; Suzuki, Naoki; Koguchi, Kazuumi; Nakagawa, Junichi; Mizuochi, Takashi; Kitayama, Ken-ichi

    2013-05-20

    This paper proposes a novel bandwidth-elastic and energy-efficient passive optical network (PON) based on the coherent interleaved frequency division multiple access (IFDMA) scheme. We experimentally demonstrate the coherent IFDMA-PON uplink transmission up-to 30 Gbps over a 30 km standard single-mode fiber with 2 × optical network units (ONUs). A low-complexity digital carrier synchronization technique enables multiple access of the ONUs on the basis of 78.1 MHz narrow band orthogonal subcarriers without any guard-bands. PMID:23736447

  14. INITIAL PLANETESIMAL SIZES AND THE SIZE DISTRIBUTION OF SMALL KUIPER BELT OBJECTS

    SciTech Connect

    Schlichting, Hilke E.; Fuentes, Cesar I.; Trilling, David E.

    2013-08-01

    The Kuiper Belt is a remnant from the early solar system and its size distribution contains many important constraints that can be used to test models of planet formation and collisional evolution. We show, by comparing observations with theoretical models, that the observed Kuiper Belt size distribution is well matched by coagulation models, which start with an initial planetesimal population with radii of about 1 km, and subsequent collisional evolution. We find that the observed size distribution above R {approx} 30 km is primordial, i.e., it has not been modified by collisional evolution over the age of the solar system, and that the size distribution below R {approx} 30 km has been modified by collisions and that its slope is well matched by collisional evolution models that use published strength laws. We investigate in detail the resulting size distribution of bodies ranging from 0.01 km to 30 km and find that its slope changes several times as a function of radius before approaching the expected value for an equilibrium collisional cascade of material strength dominated bodies for R {approx}< 0.1 km. Compared to a single power-law size distribution that would span the whole range from 0.01 km to 30 km, we find in general a strong deficit of bodies around R {approx} 10 km and a strong excess of bodies around 2 km in radius. This deficit and excess of bodies are caused by the planetesimal size distribution left over from the runaway growth phase, which left most of the initial mass in small planetesimals while only a small fraction of the total mass is converted into large protoplanets. This excess mass in small planetesimals leaves a permanent signature in the size distribution of small bodies that is not erased after 4.5 Gyr of collisional evolution. Observations of the small Kuiper Belt Object (KBO) size distribution can therefore test if large KBOs grew as a result of runaway growth and constrained the initial planetesimal sizes. We find that results from

  15. High Spectral Resolution Lidar Data

    DOE Data Explorer

    Eloranta, Ed

    2004-12-01

    The HSRL provided calibrated vertical profiles of optical depth, backscatter cross section and depoloarization at a wavelength of 532 nm. Profiles were acquired at 2.5 second intervals with 7.5 meter resolution. Profiles extended from an altitude of 100 m to 30 km in clear air. The lidar penetrated to a maximum optical depth of ~ 4 under cloudy conditions. Our data contributed directly to the aims of the M-PACE experiment, providing calibrated optical depth and optical backscatter measurements which were not available from any other instrument.

  16. Electrodynamic response of the middle atmosphere to auroral pulsations

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Croskey, C. L.; Hale, L. C.; Mitchell, J. D.; Barcus, J. R.

    1990-01-01

    The MAC/EPSILON observational campaign encompassed the use of two Nike Orion rocket payloads which studied the effects of auroral energetics on the middle atmosphere. While one payload was launched during the recovery phase of a moderate magnetic substorm, during fairly stable auroral conditions, the other was launched during highly active postbreakup conditions during which Pc5 pulsations were in progress. The energetic radiation of the first event was composed almost entirely of relativistic electrons below 200 keV, while that of the second was dominated by much softer electrons whose high X-ray fluxes exceeded the cosmic ray background as an ionizing source down to below 30 km.

  17. Discovery of intense gamma-ray flashes of atmospheric origin

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.; Bhat, P. N.; Mallozzi, R.; Horack, J. M.; Koshut, T.; Kouveliotou, C.; Pendleton, G. N.; Meegan, C. A.; Wilson, R. B.; Paciesas, W. S.

    1994-01-01

    Observations have been made of a new terrestrial phenomenon: brief (approx. millisecond), intense flashes of gamma rays, observed with space-borne detectors. These flashes must originate at altitudes in the atmosphere above at least 30 km in order to be observable by orbiting detectors aboard the Compton Gamma-Ray Observatory (CGRO). At least a dozen events have been detected over the past 2 years. The photon spectra from the events are very hard and are consistent with bremsstrahlung emission from energetic (MeV) electrons. The most likely origin of these high energy electrons, while speculative at this time, is a rare type of high altitude electrical discharge above thunderstorm regions.

  18. Sedimentary Rocks in Melas

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This Mars Global Surveyor (MGS) Orbiter Camera (MOC) image shows a butte and several other landforms eroded into light-toned, layered, sedimentary rock in southern Melas Chasma. Melas is part of the vast Valles Marineris trough system.

    Location near: 11.8oS, 74.6oW Image width: 3.0 km (1.9 mi) Illumination from: lower left Season: Southern Spring

  19. Sedimentary Rock in Candor

    NASA Technical Reports Server (NTRS)

    2005-01-01

    11 February 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dozens of light- and a few dark-toned sedimentary rock layers exposed by faulting and erosion in western Candor Chasma, part of the vast Valles Marineris trough system.

    Location near: 6.5oS, 77.0oW Image width: 3.0 km (1.9 mi) Illumination from: upper left Season: Southern Autumn

  20. Retrieval of HCl and HNO3 Profiles from Ground-Based FTIR Data Using SFIT2

    NASA Technical Reports Server (NTRS)

    Connor, Brian; Wood, Stephen W.; Keys, J. Gordon; Rinsland, Curtis P.; Murcray, Frank J.

    1998-01-01

    A recently developed algorithm, SFIT2, is used to assess profile information available in ground-based FTIR measurements of HCl and HNO3 and to analyze spectra recorded at Lauder, New Zealand, and Arrival Heights, Antarctica. It is shown that the altitude range of HCI retrievals may be extended by using multiple spectral lines. A preliminary analysis of a five year record of HNO3 at Lauder shows that the Pinatubo aerosol caused a large increase of HNO3 in a layer at about 20-30 km while having little effect at lower altitude.

  1. A ring galaxy in Canes Venatici and related ring galaxies

    SciTech Connect

    Wakamatsu, Ken-ichi; Nishida, M.T. Kobe Women's University )

    1991-04-01

    A spectroscopic observation was made of a ring-shaped object in Canes Venatici. A bright knot at the edge of the ring has a recession velocity of 10,960 + or - 30 km/s and so is confirmed as an extragalactic object. It shows no sign of nuclear activity but appears to be an H II region of intermediate excitation class. The linear diameter of the ring is 14.2 + or - 0.8 kpc, a typical size for ring galaxies. Recession velocities of several other ring galaxies are also given. 24 refs.

  2. Mass motions in impulsive flarelike brightenings as observed by OSO 8. [mechanism response for solar flares

    NASA Technical Reports Server (NTRS)

    Bruner, E. C., Jr.; Lites, B. W.

    1979-01-01

    C IV 1548-A line profiles obtained with the University of Colorado spectrometer aboard OSO 8 reveal transient, redshifted brightenings in the chromosphere-corona transition region above active regions and sunspots. In these events the intensity rises by factors of up to 5 in less than the profile sampling interval of 27 sec. These events indicate that the emitting material is moving downward at velocities of up to 30 km/sec. The increase in line intensity and the amount of motion are consistent with the interpretation of these events as pressure waves propagating down magnetic flux loops.

  3. SP.ACE: taking secondary school students' hearts and minds "up, up and away"

    NASA Astrophysics Data System (ADS)

    de Schrijver, Erik

    2005-08-01

    Secondary school students were given the opportunity to build and fly "pongsats" (small experiments weighing under 100 grams each, and packed inside a ping pong ball) on high-altitude balloons bound for 100000 feet, or 30 km: the edge of space. The need to acquire the knowledge and know-how to build successful experiments gave birth to the SP.ACE project. Over their last 3 years of secondary education, students are now learning about flight vehicles, the physical conditions in space, microcontrollers, sensors, programming, data logging, flight path analysis, and much more.

  4. Lidar Observations of Stratospheric Clouds After Volcanic Eruption of Pinatubo

    NASA Technical Reports Server (NTRS)

    Sun, Jinhui; Qiu, Jinhuan; Xia, Qilin; Zhang, Jinding

    1992-01-01

    A very large increase of backscattered light from the stratospheric aerosol layer was observed by using a ruby laser in Beijing (39 degrees 54 minutes N, 116 degrees 27 minutes E) from the end of July 1991 to March 1992. It was concluded that this increase was almost certainly due to the volcanic eruption of Mt. Pinatubo in the Philippines in June 1991. The measuring instruments used are described. Information is given in graphical form for vertical profiles, fluctuation of the maximum backscattering ratio above 20 km during the nine month period, and the time variation of the integrated backscattering coefficient at a height of 15 to 30 km.

  5. A linear accelerator for simulated micrometeors.

    NASA Technical Reports Server (NTRS)

    Slattery, J. C.; Becker, D. G.; Hamermesh, B.; Roy, N. L.

    1973-01-01

    Review of the theory, design parameters, and construction details of a linear accelerator designed to impart meteoric velocities to charged microparticles in the 1- to 10-micron diameter range. The described linac is of the Sloan Lawrence type and, in a significant departure from conventional accelerator practice, is adapted to single particle operation by employing a square wave driving voltage with the frequency automatically adjusted from 12.5 to 125 kHz according to the variable velocity of each injected particle. Any output velocity up to about 30 km/sec can easily be selected, with a repetition rate of approximately two particles per minute.

  6. The photochemistry of methane in the atmosphere of Triton

    NASA Technical Reports Server (NTRS)

    Strobel, Darrell F.; Summers, Michael E.; Herbert, Floyd; Sandel, Bill R.

    1990-01-01

    The model of Summers and Strobel (1989) for photochemical reactions in the Uranus atmosphere was modified and used for quantitative calculations of methane in the atmosphere of Triton. The principal adjustable parameters in the new model are the surface CH4 concentrations and the vigor of vertical mixing in Triton's lower atmosphere. It is shown the rate of methane photolysis that was calculated is sufficient to generate a smog of condensed C2H2, C2H4, C2H6, and C4H2 particles in the lowest 30 km of Triton's atmosphere, with an optical depth consistent with the Voyager imaging results.

  7. Test and development of inflatable spheres instrumented with miniaturized thermistors, accelerometers and pressure transducers

    NASA Technical Reports Server (NTRS)

    Luers, J. K.

    1978-01-01

    Instrumentation was developed for the high altitude inflatable sphere to measure its skin temperature, acceleration and internal pressure. The sphere without instrumentation has routinely been used over the past 10 years to provide measurements of winds, density, temperature and pressure between 100 Km and 30 Km altitude. With the miniaturized instrumentation package onboard, the system offers the potential for providing meteorological information as well as a better understanding of sphere performance and dynamics during its descent. Of the six launches of instrumented spheres only one provided telemetry data. However, many of the objectives of the program were achieved.

  8. Simulation of the transport of halogen species from the equatorial and mid-latitude stratosphere to the polar stratosphere in a two-dimensional model

    NASA Technical Reports Server (NTRS)

    Yung, Yuk L.; Shia, R. L.; Allen, M.; Zurek, R. W.; Crisp, D.; Wen, J. S.

    1988-01-01

    The bulk of O sub 3 destruction in the Antarctic stratosphere takes place in the lower stratosphere between 15 and 25 km. Both O sub 3 and the halogen reservoir species have their origins in the higher altitude region (20 to 30 km) in the equatorial and mid-latitude stratosphere. Using the Caltech-JPL two-dimensional residual circulation model, researchers investigate the growth of stratospheric halogen due to the increase of CFCl sub 3 and CF sub 2 Cl sub 2.

  9. Melting and differentiation in Venus with a cold start: A mechanism of the thin crust formation

    NASA Technical Reports Server (NTRS)

    Solomatov, Viatcheslav S.; Stevenson, David J.

    1992-01-01

    Recent works argue that the venusian crust is thin: less than 10-30 km. However, any convective model of Venus unavoidably predicts melting and a fast growth of the basaltic crust, up to its maximum thickness of about 70 km limited, by the gabbro-eclogite phase transition. The crust is highly buoyant due to both its composition and temperature and it is problematic to find a mechanism providing its effective recycling and thinning in the absence of plate tectonics. There are different ways to solve this contradiction. This study suggests that a thin crust can be produced during the entire evolution of Venus if Venus avoided giant impacts.

  10. Impact of an asteroid or comet in the ocean and extinction of terrestrial life

    NASA Technical Reports Server (NTRS)

    Ahrens, T. J.; Okeefe, J. D.

    1982-01-01

    Finite difference calculations describing the impact mechanics associated with a 10 to 30 km diameter silicate or water object impacting a 5 km deep ocean overlying a silicate solid planet demonstrate that from 12 to 15% of the bolide energy resides in the water. It is speculated that minimal global tsunami run-up heights on the continents would be 300-400 meters, and that such waves would inundate all low altitude continental areas, and strip and silt-over virtually all vegetation. As a result the terrestrial animal food chain would be seriously perturbed. This could in turn cause extinction of large terrestrial animals.

  11. Observatorio UC at Santa Martina: a small observing facility operated by PUC

    NASA Astrophysics Data System (ADS)

    Baffico, M.; Avila, G.; Baade, D.; Bendek, E.; Guirao, C.; Gonzalez, O.; Marchant, P.; Salas, V.; Toledo, I.; Vasquez, S.; Vanzi, L.

    2008-07-01

    The Department of Astronomy and Astrophysics (DAA) of the Pontificia Universidad Católica de Chile (PUC) operates a small observatory at Santa Martina hills located in the outskirts of Santiago. Despite the close distance (about 30 km) from the centre of a very large metropolitan area, the observatory offers excellent conditions in terms of number of clear nights and relatively good conditions in terms of light pollution and image quality. The observatory is mostly used for didactic purposes, however we are evaluating scientific applications as well.

  12. Comparing Water Vapor Mixing Ratio Profiles and Cloud Vertical Structure from Multiwavelength Raman Lidar Retrievals and Radiosounding Measurements

    NASA Astrophysics Data System (ADS)

    Costa-Surós, Montserrat; Stachlewska, Iwona S.; Markowicz, Krzysztof

    2016-06-01

    A study of comparison of water vapor mixing ratio profiles, relative humidity profiles, and cloud vertical structures using two different instruments, a multiwavelength Aerosol-Depolarization-Raman lidar and radiosoundings, is presented. The observations were taken by the lidar located in Warsaw center and the radiosoundings located about 30km to the North in Legionowo (Poland). We compared the ground-based remote sensing technology with in-situ method in order to improve knowledge about water content thought the atmosphere and cloud formation. The method used for retrieving the cloud vertical structure can be improved comparing the radiosonde results with the lidar observations, which show promising results.

  13. Lunar crater depths from orbiter IV long-focus photographs

    USGS Publications Warehouse

    Arthur, D.W.G.

    1974-01-01

    The paper presents method and results for the determination of the depths of more than 1900 small lunar craters from measures of shadows on the long-focus pictures obtained by Lunar Orbiter IV. The method for converting the measured shadow length into the true length in nature of the shadow hypotenuse is new and is applicable to other planetary bodies provided comparable spacecraft ephemerides are available. The measures were made with a simple surveyor's plotting scale on the standard Orbiter IV photographic enlargements. The results indicate that the smaller lunar (D < 30 km) craters are appreciably deeper than is indicated by earlier work using imagery obtained at terrestrial observatories. ?? 1974.

  14. Infrared and radar signatures of lunar craters - Implications about crater evolution

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.; Cutts, J. A.; Shorthill, R. W.; Zisk, S. H.

    1980-01-01

    Geological models accounting for the strongly crater size-dependent IR and radar signatures of lunar crater floors are examined. The simplest model involves the formation and subsequent 'gardening' of an impact melt layer on the crater floor, but while adequate in accounting for the gradual fading of IR temperatures and echo strengths in craters larger than 30 km in diameter, it is inadequate for smaller ones. It is concluded that quantitative models of the evolution of rock populations in regoliths and of the interaction of microwaves with regoliths are needed in order to understand crater evolutionary processes.

  15. Gamma ray flashes add to mystery of upper atmosphere

    NASA Astrophysics Data System (ADS)

    Atmospheric electricity research has come a long way since Benjamin Franklin's kite-flying days. But what researchers have been learning lately about above-thunderstorm electricity has wrought a whole new era of mysteries.For a start, last summer a Colorado meteorologist sparked interest in a terrestrial phenomenon that the community first observed more than 100 years ago: optical flashes that occur above thunderstorms—at least 30 km above Earth. Walter Lyons with the Ft. Collins-based Mission Research Corporation, demonstrated that such flashes are not anomalies, as conventional scientific wisdom had held. He filmed hundreds of flashes during a 2-week period.

  16. Present concept on current water protection and remediation activities for the areas contaminated by the 1986 Chernobyl accident

    SciTech Connect

    Voitsekhovitch, O.; Prister, B.; Nasvit, O.; Los, I.; Berkovski, V.

    1996-07-01

    The results of radiation monitoring data and migration pathway analysis of water bodies within areas affected by the 1986 Chernobyl accident provide a unique opportunity for decision-makers working in other extensively contaminated regions to optimize their approaches to surface and groundwater protection. Most engineering measures within the Chernobyl 30-km exclusion zone were focused on preventing secondary contamination of surface and groundwater from entering the Pripyat River and the Kiev Reservoir. However, implementation of these measures required huge financial and human resources. Therefore, lessons about post-accidental water protection activities can be learned form the Chernobyl example. 9 refs., 9 figs.

  17. Range-wide patterns of greater sage-grouse persistence

    USGS Publications Warehouse

    Aldridge, C.L.; Nielsen, S.E.; Beyer, H.L.; Boyce, M.S.; Connelly, J.W.; Knick, S.T.; Schroeder, M.A.

    2008-01-01

    Aim: Greater sage-grouse (Centrocercus urophasianus), a shrub-steppe obligate species of western North America, currently occupies only half its historical range. Here we examine how broad-scale, long-term trends in landscape condition have affected range contraction. Location: Sagebrush biome of the western USA. Methods: Logistic regression was used to assess persistence and extirpation of greater sage-grouse range based on landscape conditions measured by human population (density and population change), vegetation (percentage of sagebrush habitat), roads (density of and distance to roads), agriculture (cropland, farmland and cattle density), climate (number of severe and extreme droughts) and range periphery. Model predictions were used to identify areas where future extirpations can be expected, while also explaining possible causes of past extirpations. Results: Greater sage-grouse persistence and extirpation were significantly related to sagebrush habitat, cultivated cropland, human population density in 1950, prevalence of severe droughts and historical range periphery. Extirpation of sage-grouse was most likely in areas having at least four persons per square kilometre in 1950, 25% cultivated cropland in 2002 or the presence of three or more severe droughts per decade. In contrast, persistence of sage-grouse was expected when at least 30 km from historical range edge and in habitats containing at least 25% sagebrush cover within 30 km. Extirpation was most often explained (35%) by the combined effects of peripherality (within 30 km of range edge) and lack of sagebrush cover (less than 25% within 30 km). Based on patterns of prior extirpation and model predictions, we predict that 29% of remaining range may be at risk. Main Conclusions: Spatial patterns in greater sage-grouse range contraction can be explained by widely available landscape variables that describe patterns of remaining sagebrush habitat and loss due to cultivation, climatic trends, human

  18. Demographic, agricultural products, and food consumption data for a collective farm in Oranoe District, Ivankov District, Kiev Region, Ukraine

    SciTech Connect

    Ryabov, I N; Davidenko, G M; Templeton, W L; ,

    1992-07-01

    This report provides some demographic, agricultural and food consumption data for the collective farms ( Kybisheva,'' composed of three villages) in the Oranoe Department, District of Ivankov, Kiev Region. This area is situated approximately 15 km south of the Chernobyl 30-km Exclusion Zone. The levels of {sup 137}Cs are approximately 5--10 curies/km{sup 2}. This data was collected by the Integrated Radioecological Expedition to Chernobyl of the Russian Academy of Sciences as part of the co-operative studies on environmental radiation dose assessment conducted under the US/USSR Joint Co-operative Committee on Civilian Nuclear Reactor Safety (JCCCNRS) established in 1989.

  19. Native gold and companion minerals in the Cenozoic sediments of the Ural Foredeep

    NASA Astrophysics Data System (ADS)

    Petrovsky, D. V.; Silaev, V. I.; Zharkov, V. A.; Petrovsky, V. A.

    2012-11-01

    Clastic gold in the Cenozoic sediments of the Ural Foredeep is referred to the apron and aureole dynamic types of alluvial placers, which are formed at a distance of 10-30 km from their sources. The gold grains vary appreciably in size and chemical composition of individuals and are characterized by good round-ness and high degree of alluvial refining. It is suggested that endogenic gold occurrences in mountainous regions of the Polar and Subpolar Urals were the main sources of clastic gold grains.

  20. The Brownell and Ness County (1894) L6 chondrites - Further sorting-out of Ness County meteorites

    NASA Astrophysics Data System (ADS)

    Rubin, A. E.; Read, W. F.

    1984-09-01

    Brownell is a new moderately shocked L6 chondrite from Ness County, KS, that is petrologically distinct from the other L6 chondrites from Ness County. These latter meteorites, Wellmanville, Franklinville, and Ness County (1894), are very similar in their olivine and low-Ca pyroxene compositional distributions, kamacite Co contents, modal abundances of metallic Fe, Ni, and presence of martensitic metallic Fe, Ni (about 14 wt pct Ni). However, their silicates indicate that they have been shocked to different extents. It is suggested that all three probably represent a single heterogeneously-shocked L6 fragmental breccia that fell over a large area over 30 km in length.

  1. Uppermantle anisotropy and the oceanic lithosphere

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.; Regan, J.

    1983-01-01

    Published Rayleigh and Love wave phase and group velocity data have been inverted taking into account sphericity, anelastic dispersion, and transverse isotropy. For a PREM-type modular parameterization, the thickness of the high velocity mantle seismic lithosphere (LID) varies in thickness from about 30 km for young ocean to about 50 km for old ocean, much less than previous estimates based on isotropic inversion of similar data. This LID thickness is comparable to the elastic or flexural thickness found from studies of seamount loading and flexure at trenches, suggesting that the thickness of the lithosphere may be controlled by mineralogy, composition, or crystal orientation rather than by temperature alone.

  2. Present concept on current water protection and remediation activities for the areas contaminated by the 1986 Chernobyl accident.

    PubMed

    Voitsekhovitch, O; Prister, B; Nasvit, O; Los, I; Berkovski, V

    1996-07-01

    The results of radiation monitoring data and migration pathway analysis of water bodies within areas affected by the 1986 Chernobyl accident provide a unique opportunity for decision-makers working in other extensively contaminated regions to optimize their approaches to surface and groundwater protection. Most engineering measures within the Chernobyl 30-km exclusion zone were focused on preventing secondary contamination of surface and groundwater from entering the Pripyat River and the Kiev Reservoir. However, implementation of these measures required huge financial and human resources. Therefore, lessons about post-accidental water protection activities can be learned from the Chernobyl example. PMID:8655324

  3. NGC 2242 - A newly discovered planetary nebula

    NASA Astrophysics Data System (ADS)

    Maehara, H.; Okamura, S.; Noguchi, T.; He, X. T.; Liu, J. Y.; Huang, Y. W.; Feng, X.-C.

    1987-05-01

    Photometric and spectroscopic analyses are made for the object NGC 2242, which was detected in a survey of emission-line galaxies by Liu et al. (1986). Luminosity and color distributions and a small heliocentric velocity (-30 km s-1) are all inconsistent with previous classifications as a galaxy. NGC 2242 is probably a planetary nebula located at ≡2 kpc from the sun and at ≡500 pc above the galactic plane. Characteristics and physical parameters of NGC 2242 are discussed in some detail.

  4. Melting and differentiation in Venus with a cold start: A mechanism of the thin crust formation

    NASA Astrophysics Data System (ADS)

    Solomatov, Viatcheslav S.; Stevenson, David J.

    1992-12-01

    Recent works argue that the venusian crust is thin: less than 10-30 km. However, any convective model of Venus unavoidably predicts melting and a fast growth of the basaltic crust, up to its maximum thickness of about 70 km limited, by the gabbro-eclogite phase transition. The crust is highly buoyant due to both its composition and temperature and it is problematic to find a mechanism providing its effective recycling and thinning in the absence of plate tectonics. There are different ways to solve this contradiction. This study suggests that a thin crust can be produced during the entire evolution of Venus if Venus avoided giant impacts.

  5. The Brownell and Ness County (1894) L6 chondrites - Further sorting-out of Ness County meteorites

    NASA Technical Reports Server (NTRS)

    Rubin, A. E.; Read, W. F.

    1984-01-01

    Brownell is a new moderately shocked L6 chondrite from Ness County, KS, that is petrologically distinct from the other L6 chondrites from Ness County. These latter meteorites, Wellmanville, Franklinville, and Ness County (1894), are very similar in their olivine and low-Ca pyroxene compositional distributions, kamacite Co contents, modal abundances of metallic Fe, Ni, and presence of martensitic metallic Fe, Ni (about 14 wt pct Ni). However, their silicates indicate that they have been shocked to different extents. It is suggested that all three probably represent a single heterogeneously-shocked L6 fragmental breccia that fell over a large area over 30 km in length.

  6. Design of a three-dimensional site-scale model for the unsaturated zone at Yucca Mountain, Nevada

    SciTech Connect

    Wittwer, C.S.; Bodvarsson, G.S.; Chornack, M.P.; Flint, A.L.; Lewis, B.D.; Spengler, R.W.; Flint, L.E.; Rautman, C.A.

    1992-01-01

    A three-dimensional model of moisture flow within the unsaturated zone at Yucca Mountain is being developed. This site-scale model covers an area of about 30 km{sup 2} and is bounded by major faults to the east and west. A detailed numerical grid has been developed based on location of boreholes, different infiltration zones, hydrogeological units and their outcrops, major faults, and water level data. Different maps, such as contour maps and isopachs maps, are presented for the different infiltration zones, and for the base of the Tiva Canyon, the Paintbrush, and the Topopah Spring hydrogeological units.

  7. Design of a three-dimensional site scale model for the unsaturated zone at Yucca Mountain, Nevada

    SciTech Connect

    Wittwer, C.S.; Bodvarsson, G.S.; Chornack, M.P.; Flint, A.L.; Lewis, B.D.; Spengler, R.W.; Flint, L.E.; Rautman, C.A.

    1992-10-01

    This paper discusses a three-dimensional model of moisture flow within the unsaturated zone at Yucca Mountain which is being developed. The site-scale model covers an area of about 30 km{sup 2} and is bounded by major faults to the east and west. A detailed numerical grid has been developed based on locations of boreholes, different infiltration zones, hydrogeological units and their outcrops, major faults, and water level data. Different maps, such as contour maps and isopachs maps, are presented for the different infiltration zones, and for the base of the Tiva Canyon, the Paintbrush, and the Topopah Spring hydrogeological units.

  8. Titan's Elusive Lakes? Properties and Context of Dark Spots in Cassini TA Radar Data

    NASA Technical Reports Server (NTRS)

    Lorenz, R. D.; Elachi, C.; Stiles, B.; West, R.; Janssen, M.; Lopes, R.; Stofan, E.; Paganelli, F.; Wood, C.; Kirk, R.

    2005-01-01

    Titan's atmospheric methane abundance suggests the likelihood of a surface reservoir of methane and a surface sink for its photochemical products, which might also be predominantly liquid. Although large expanses of obvious hydrocarbon seas have not been unambiguously observed, a number of rather radar-dark spots up to approximately 30 km across are observed in the Synthetic Aperture Radar (SAR) data acquired during the Cassini TA encounter on October 26th 2004. Here we review the properties and setting of these dark spots to explore whether these may be hydrocarbon lakes.

  9. In-Flight Performance of the TES Loop Heat Pipe Rejection System: Seven Years in Space

    NASA Technical Reports Server (NTRS)

    Rodriquez, Jose I.; Na-Nakornpanom, Arthur

    2012-01-01

    The Tropospheric Emission Spectrometer (TES) is an infrared, high spectral resolution Fourier transform spectrometer with a 3.3 to 15.4 micron wavelength coverage. TES is a scanning instrument intended for determining the chemical state of the Earth's lower atmosphere (troposphere) from the surface to 30+ km. TES produces vertical profiles of important pollutant and greenhouse gases such as carbon monoxide, ozone, methane, and water vapor on a global scale every other day. TES was launched into orbit onboard NASA's earth Observing System Aura spacecraft on July 15, 2004 from Vandenberg Air Force Base, California.

  10. Diurnal variation of stratospheric chlorine monoxide - A critical test of chlorine chemistry in the ozone layer

    NASA Technical Reports Server (NTRS)

    Solomon, P. M.; De Zafra, R.; Parrish, A.; Barrett, J. W.

    1984-01-01

    Ground-based observations of a mm-wave spectral line at 278 GHz have yielded stratospheric chlorine monoxide column density diurnal variation records which indicate that the mixing ratio and column density of this compound above 30 km are about 20 percent lower than model predictions based on 2.1 parts/billion of total stratospheric chlorine. The observed day-to-night variation is, however, in good agreement with recent model predictions, both confirming the existence of a nighttime reservoir for chlorine and verifying the predicted general rate of its storage and retrieval.

  11. The Chacana caldera complex in Ecuador

    NASA Astrophysics Data System (ADS)

    Hall, Minard L.; Mothes, Patricia A.

    2008-10-01

    The Chacana caldera, located immediately east of Quito, capital of Ecuador, forms the most-northern edifice of Ecuadorõs rhyolite province. It is a 50X30 km Pleistocene structure that has remained active into historic times. Vitrophyres, welded tuffs, and ignimbrites of rhyolitic and dacitic composition constitute the outer flanks, meantime syngenetic breccias and tuffs, capped later by extensive dacite lava flows and basin sediments, filled the calderaõs depression. A notable resurgence occurred that lifted quiet-water sediments to over 4000 m in elevation. The area has numerous hot springs, and little seismic activity.

  12. The Present and Future of Occultation Surveys of the Outer Solar System: From TAOS to Whipple

    NASA Astrophysics Data System (ADS)

    Bianco, Federica; Alcock, C.; Murray, S.; Werner, M.; TAOS Collaboration

    2009-09-01

    We have analyzed new data from the TAOS occultation survey and set new, sensitive upper limits to the number density of KBOs of diameter D<30 km, and of objects in Sedna-like orbits. We present the first constraints on models of the formation and evolution of the Solar System based on occultation survey data. We show what future occultation programs must be able to do in order to survey comprehensively the populations of small bodies in the outer solar system, and describe a Discovery class mission, Whipple, that can achieve these goals.

  13. New evidence for magmatic intrusion beneath the Rio Grande rift, New Mexico.

    USGS Publications Warehouse

    Towle, J.N.

    1980-01-01

    An analysis of the geomagnetic variation field across the Rio Grande rift has identified two concentrations of telluric current flow beneath the rift caused by channeling of telluric currents in electrically conductive structures in the crust and upper mantle. A shallow conductor nearly coincides with a very strong reflection in a high-resoltuion seismic-reflection profile across the central Rio Grande graben which has been attributed to a lens at mid-crustal depth. The deep (more than 30 km) conductor is 200 km wide and may indicate anomalously high temperatures and, by inference, a thinning of the lithosphere beneath the rift.-Authors

  14. The Black Mountain asperity - Seismic hazard of the southern San Francisco Peninsula, California

    NASA Technical Reports Server (NTRS)

    Scholz, C. H.

    1985-01-01

    A slip deficit region running 75 km from Black Mountain south of Palo Alto to San Juan Battista is studied to assess earthquake hazard. If this region were ruptured in its entirety, the event would produce a M-sub-s = 6.9 earthquake. The conditional probability of this rupturing in the near future is the highest of any section of the San Andreas fault except Parkfield. This earthquake would rupture 30 km farther northwest and be about 3 times larger than that previously proposed by others (Lindh, 1983, and Sykes and Nishenko, 1984). This constitutes a greater risk to the southern San Francisco Peninsula than previously expected.

  15. Scramjet Research Activities at the Institute of Flight Propulsion of the Technische Universitaet Muenchen

    NASA Astrophysics Data System (ADS)

    Maier, D.; Kirstein, S.; Fuhrmann, T.; Rocci Denis, S.; Hupfer, A.; Kau, H.-P.

    2009-01-01

    At the Institute of Flight Propulsion (LFA) of the Technische Universitaet Muenchen scramjet research has been carried on since the 70's. Based on the experiences gained during the last decades experimental and numerical studies on scramjet engines are currently conducted within a research training group (GRK1095) funded by the German Research Foundation (DFG). The main goal of this program is to design a fixed geometry scramjet engine for a Mach 8 flight at an operating altitude of 30 km. In addition to a historical overview latest research results are presented in this paper.

  16. Multiwavelength lidar measurements of stratospheric aerosols above Spitsbergen during winter 1992/93

    SciTech Connect

    Beyerle, G.; Neuber, R.; Schrems, O. ); Wittrock, F. ); Knudsen, B. )

    1994-01-01

    Using a multiwavelength lidar the authors measured aerosols from the tropopause to altitudes of 30 km in the period December 1992 to March 1993. They analyzed backscatter and depolarization measurements to infer information on aerosol size and phase. During most of this period they saw evidence of a liquid drop aerosol layer in the lower stratosphere which was of a volcanic origin. In January they observed polar stratospheric clouds on numerous occasions, and particle size was found to depend strongly on the cooling rate.

  17. Constraining Enceladus’s ice shell thickness using tidally driven Coulomb failure models of the tiger stripe fractures

    NASA Astrophysics Data System (ADS)

    Olgin, J. G.; Smith-Konter, B. R.; Pappalardo, R. T.

    2009-12-01

    The thickness of Enceladus’s ice shell, and subsequently the depth of its underlying ocean, plays an important role in determining the magnitude and orientation of tidal stresses on the surface of the satellite. The objective of this study is to attempt to constrain Enceladus’s ice shell thickness through assessment of tidally driven Coulomb failure of the tiger stripe fractures, probable sources of tectonic activity that reside along Enceladus’s south polar region. Using the SatStress computational model and assuming a global ocean and uniform ice shell thickness, we compare tidal stresses resulting from a suite of models of variable ice shell thickness (6 km, 24 km, 30 km, 40 km, 50 km, 75 km, and 90 km). Evaluation of the Love numbers for each model (l2, h2 and k2) suggest that ice shell thicknesses greater than a few 10s of km are not capable of generating stress conditions conducive to fault failure on Enceladus. We further investigate the feasibility of tiger stripe failure by applying a Coulomb failure model to the resulting tidal stresses. Based on previous work, we have shown that a 24 km thick ice shell model is capable of generating stress conditions that promote Coulomb failure and strike-slip displacements of ~0.4 m along some portions of the tiger stripe system, assuming a coefficient of friction of 0.2. We compare this reference model to the 6 km, 30 km, 40 km, 50 km, 75 km, and 90 km ice shell models and find that thin to moderate ice shell models do indeed support fault failure, while thick ice shell models do not. Models based on a 6 km ice shell thickness can yield strike-slip displacements on the order of 1 m along all segments of the tiger stripe system. Models based on a 30 km ice shell thickness can also generate strike-slip displacements (~0.1 m), however only on isolated fault segments. Finally, models based on a 40 km ice shell thickness or greater cannot generate stresses capable of Coulomb failure along any of the tiger stripe

  18. 40 CFR 86.528-78 - Transmissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: Shift Speed 1st to 2d gear 19 km/h (11.8 mi/h). 2d to 3d gear 33 km/h (20.5 mi/h). 3d to 4th gear 44 km... to 2d gear 30 km/h (18.6 mi/h). 2d to 3d gear 45 km/h (28.0 mi/h). 3d to 4th gear 60 km/h (37.3...

  19. 40 CFR 86.528-78 - Transmissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: Shift Speed 1st to 2d gear 19 km/h (11.8 mi/h). 2d to 3d gear 33 km/h (20.5 mi/h). 3d to 4th gear 44 km... to 2d gear 30 km/h (18.6 mi/h). 2d to 3d gear 45 km/h (28.0 mi/h). 3d to 4th gear 60 km/h (37.3...

  20. 40 CFR 86.528-78 - Transmissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: Shift Speed 1st to 2d gear 19 km/h (11.8 mi/h). 2d to 3d gear 33 km/h (20.5 mi/h). 3d to 4th gear 44 km... to 2d gear 30 km/h (18.6 mi/h). 2d to 3d gear 45 km/h (28.0 mi/h). 3d to 4th gear 60 km/h (37.3...

  1. 40 CFR 86.528-78 - Transmissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Shift Speed 1st to 2d gear 19 km/h (11.8 mi/h). 2d to 3d gear 33 km/h (20.5 mi/h). 3d to 4th gear 44 km... to 2d gear 30 km/h (18.6 mi/h). 2d to 3d gear 45 km/h (28.0 mi/h). 3d to 4th gear 60 km/h (37.3...

  2. 40 CFR 86.528-78 - Transmissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: Shift Speed 1st to 2d gear 19 km/h (11.8 mi/h). 2d to 3d gear 33 km/h (20.5 mi/h). 3d to 4th gear 44 km... to 2d gear 30 km/h (18.6 mi/h). 2d to 3d gear 45 km/h (28.0 mi/h). 3d to 4th gear 60 km/h (37.3...

  3. MOLA Global map of surface gradients on Mars

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Absolute slopes on 30-km baselines indicate the magnitude of typical regional tilts of that scale. The Northern hemisphere is flatter than the South, and shows some linear slope breaks, for example north of Alba Patera (40N, 250E) and the Tharsis province. The major volcanos display flanks slopes of 2.5-5 degrees, comparable to Hawaiian shields. The southwest rim of the Hellas impact basin appears relatively eroded, with shallower typical slopes. A shaded relief map of the topography is overlaid is monochrome.

  4. Simulation of CO2 release at 800 km altitude

    NASA Astrophysics Data System (ADS)

    Setayesh, A.

    1993-08-01

    The SOCRATES contamination-interaction code has been used to simulate the reactions of 0 + CO2 yields CO2(v) + O, O + CO2 - CO(v) + O2, and CO2 + H - CO + OH(v) at an altitude of 800 km in both ram and wake directions of the spacecraft. These simulations show that the radiation from these reactions can be measurable for the parameters which have been used in these calculations. The investigation carries out the simulations as much as 30 km from the spacecraft. The radiative intensity of CO(v) and OH(v) show the highest and lowest, respectively.

  5. A New View on Interstellar Dust - High Fidelity Studies of Interstellar Dust Analogue Tracks in Stardust Flight Spare Aerogel

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Postberg F.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Bugiel, S.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G. J.; Frank, D.; Gainsforth, Z.

    2011-01-01

    In 2000 and 2002 the Stardust Mission exposed aerogel collector panels for a total of about 200 days to the stream of interstellar grains sweeping through the solar system. The material was brought back to Earth in 2006. The goal of this work is the laboratory calibration of the collection process by shooting high speed [5 - 30km/s] interstellar dust (ISD) analogues onto Stardust aerogel flight spares. This enables an investigation into both the morphology of impact tracks as well as any structural and chemical modification of projectile and collector material. First results indicate a different ISD flux than previously assumed for the Stardust collection period.

  6. Laser phase noise compensation in long-range OFDR by using an optical fiber delay loop

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Fan, Xinyu; Wang, Shuai; Yang, Guangyao; Liu, Qingwen; He, Zuyuan

    2016-04-01

    We propose and experimentally demonstrate a novel technique to compensate the laser phase noise in long-range OFDR by using an optical fiber delay loop, which mainly consists of a delay fiber and a frequency shifter. The delay fiber is used to shorten the optical path difference between two arms of the interferometer, and the frequency shifter works as a counter for taking the number of lightwave circulated in the loop. The preliminary experiment shows a successful compensation effect, and a 10 cm spatial resolution over 30 km measurement range is realized by using this method.

  7. VizieR Online Data Catalog: RV and vsini of southern stars (de Medeiros+, 2014)

    NASA Astrophysics Data System (ADS)

    de Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordstrom, B.; Mayor, M.

    2013-11-01

    Rotational and radial velocities have been measured for 1589 evolved stars of spectral types F, G, and K and luminosity classes IV, III, II, and Ib, based on observations carried out with the CORAVEL spectrometers. The precision in radial velocity is better than 0.30km/s per observation, whereas rotational velocity uncertainties are typically 1.0km/s for subgiants and giants and 2.0km/s for class II giants and Ib supergiants. (1 data file).

  8. Lunar Crustal History Recorded in Lunar Anorthosites

    NASA Technical Reports Server (NTRS)

    Nyquist, Laurence E.; Shih, C.-Y.; Reese, D.; Park, J.; Bogard. D.; Garrison, D.; Yamaguchi, A.

    2010-01-01

    Anorthosites occur ubiquitously within the lunar crust at depths of 3-30 km in apparent confirmation of the Lunar Magma Ocean (LMO) hypothesis. We have dated lunar anorthosite 67075, a Feldspathic Fragmental Breccia (FFB) collected near the rim of North Ray Crater by the Sm-Nd and Rb-Sr techniques. We also have dated an anorthositic white clast (WC) in lunar meteorite Dhofar 908 by the Ar-39-Ar-40 technique and measured whole rock (WR) Sm-Nd data for a companion sample. We discuss the significance of the ages determined for these and other anorthosites for the early magmatic and bombardment history of the moon.

  9. Two-point attack on the two nonorthogonal states QKD protocol over a fiber optic channel

    NASA Astrophysics Data System (ADS)

    Yang, Li; Wu, Ling-An

    2005-01-01

    We suggest here a two-point eavesdropping strategy aimed at a two nonorthogonal states protocol of quantum key distribution over a fiber-optic channel. When the single-photon sources and detectors of Alice, Bob and the two Eve are all ideal, the two-point attack can break the two nonorthogonal states protocol if the distance between Alice and Bob is longer than 30 km. However, Bennett's original multi-photon protocol is secure against both two-point and beam splitting attacks, though the protocol is realized with a weak pulsed source.

  10. The Optical Spectrum of SrOH Re-Visited Zeeman Effect, High-Resolution Spectroscopy and Franck-Condon Factors.

    NASA Astrophysics Data System (ADS)

    Nguyen, Trung; Kokkin, Damian L.; Steimle, Timothy; Kozyryev, Ivan; Doyle, John M.

    2015-06-01

    Motivated by a diverse range of applications in physics and chemistry, currently there is great interest in the cooling of molecules to very low temperatures (≤1 mK). Direct laser cooling has been previously demonstrated for the diatomic radicals SrF, YO, and CaF, and most recently a three-dimensional magneto-optical trap (MOT) of SrF molecules was achieved. To determine the possibility of laser cooling for polyatomic molecules containing three or more atoms, detailed information is required about their Franck-Condon factors (FCFs) for emission from the excited states of interest. Here we report on the high-resolution laser excitation spectra, recorded field-free and in the presence of a static magnetic field, and on the dispersed fluorescence (DF) spectra for the A^2Π1/2 ← X^2σ^+ and B^2σ^+ ← X ^2σ^+ electronic transitions of SrOH. The DF spectra were analyzed to precisely determine FCFs and compared with values predicted using a normal coordinate GF matrix approach. The recorded Zeeman spectra were analyzed to determine the magnetic moments. Implication for proposed laser cooling and trapping experiments for SrOH will be presented. E.S. Shuman, J.F. Barry and D. DeMille, Nature 467, 820 (2010) J.F. Barry, E.S. Shuman, E.B. Norrgard and D. DeMille, Phys. Rev. Lett. 108, 103002 (2012) M.T. Hummon, M. Yeo, B.K. Stuhl, A.L. Collopy, Y. Xia, and J. Ye, Phys. Rev. Lett. 110, 143001 (2013) M. Yeo, M.T. Hummon, A.L. Collopy, B. Yan, B. Hemmerling, E. Chae, J.M. Doyle, and J. Ye, arXiv:1501.04683 (2015) V. Zhelyazkova, A. Cournol, T.E. Wall, A. Matsushima, J.J. Hudson, E.A. Hinds, M.R. Tarbutt, and B.E. Sauer, Phys. Rev. A 89, 053416 (2014) J.F. Barry, D.J. McCarron, E.B. Norrgard, M.H. Steinecker and D. DeMille, Nature 512, 286 (2014) D.J. McCarron, E.B. Norrgard, M.H. Steinecker and D. DeMille, arXiv:1412.8220 (2014)

  11. Alloplastic adjuncts in breast reconstruction

    PubMed Central

    Cabalag, Miguel S.; Rostek, Marie; Miller, George S.; Chae, Michael P.; Quinn, Tam; Rozen, Warren M.

    2016-01-01

    Background There has been an increasing role of acellular dermal matrices (ADMs) and synthetic meshes in both single- and two-stage implant/expander breast reconstruction. Numerous alloplastic adjuncts exist, and these vary in material type, processing, storage, surgical preparation, level of sterility, available sizes and cost. However, there is little published data on most, posing a significant challenge to the reconstructive surgeon trying to compare and select the most suitable product. The aims of this systematic review were to identify, summarize and evaluate the outcomes of studies describing the use of alloplastic adjuncts for post-mastectomy breast reconstruction. The secondary aims were to determine their cost-effectiveness and analyze outcomes in patients who also underwent radiotherapy. Methods Using the PRSIMA 2009 statement, a systematic review was conducted to find articles reporting on the outcomes on the use of alloplastic adjuncts in post-mastectomy breast reconstruction. Multiple databases were searched independently by three authors (Cabalag MS, Miller GS and Chae MP), including: Ovid MEDLINE (1950 to present), Embase (1980 to 2015), PubMed and Cochrane Database of Systematic Reviews. Results Current published literature on available alloplastic adjuncts are predominantly centered on ADMs, both allogeneic and xenogeneic, with few outcome studies available for synthetic meshes. Outcomes on the 89 articles, which met the inclusion criteria, were summarized and analyzed. The reported outcomes on alloplastic adjunct-assisted breast reconstruction were varied, with most data available on the use of ADMs, particularly AlloDerm® (LifeCell, Branchburg, New Jersey, USA). The use of ADMs in single-stage direct-to-implant breast reconstruction resulted in lower complication rates (infection, seroma, implant loss and late revision), and was more cost effective when compared to non-ADM, two-stage reconstruction. The majority of studies demonstrated

  12. Vibronic Spectroscopy of Hetero Dihalo-Benzyl Radicals Generated by Corona Discharge : Jet-Cooled Chlorofluorobenzyl Radicals

    NASA Astrophysics Data System (ADS)

    Yoon, Young; Lee, Sang

    2015-06-01

    .~Phys. 136, 174306 (2012). S.~Y.~Chae, Y.~W.~Yoon, and S.~K.~Lee, Chem.~Phys.~Lett. 612, 134 (2014).

  13. Venus - Crater distributions at low northern latitudes and in the southern hemisphere from new Arecibo observations

    NASA Technical Reports Server (NTRS)

    Campbell, D. B.; Stacy, N. J. S.; Hine, A. A.

    1990-01-01

    Arecibo high resolution radar data covering approximately 23 percent of the surface of Venus were analyzed for circular features with crater-like appearances. Overlapping Venera 15/16 radar data, with its more normal to the surface viewing geometry, was used to verify crater diameters measured from the Arecibo data. A comparison of the diameter-frequency distribution of the possible impact features in the Arecibo data for northern latitudes south of 40 deg N and for the southern hemisphere with the distribution from the Venera 15/16 data for the northernmost quarter of the planet indicated similar distributions for large crater-like features with diameters greater than approximately 30 km, but a deficiency of smaller craters in the Arecibo data. One possible process responsible for the density differences of small craters is a difference in the rate of volcanic resurfacing. An increase in the resurfacing rate of approximately 50 percent would explain the lower density of small craters in the area covered by the Arecibo data compared with the Venera data, but would not account for the differences being confined to the less than 30 km crater diameter range.

  14. Cancer Risk in Adult Residents near Nuclear Power Plants in Korea - A Cohort Study of 1992-2010

    PubMed Central

    Li, Zhong Min

    2012-01-01

    This study evaluated cancer risk for adult residents near Nuclear Power Plants (NPPs) in Korea through a valid prospective cohort study during 1992-2010. The study cohort was composed of 11,367 adults living within a five km radius from the NPPs for the exposed and 24,809 adults for the non-exposed or reference cohort set at two different levels of proximity; 5-30 km radius and more than 30 km radius away from NPPs. In 303,542.5 person-years of follow-up, a total of 2,298 cancer cases of all sites, or 1,377 radio-inducible cancers diagnosed during 1992-2008 were ascertained. Multiple adjusted hazard ratios and 95% confidence intervals were estimated using multivariate Cox proportional hazard model. There were no epidemiological evidence for increased risk of cancer due to radiation from NPPs. Radiological study results or surveillance data of radiation doses around NPPs could be well documented for risk estimation of radio-inducible cancers, instead of epidemiological study results of the long-time required. Continuous surveillance of quantitative measures of dose levels around NPPs and radiation exposures to the residents is warranted. PMID:22969244

  15. Delayed production of sulfuric acid condensation nuclei in the polar stratosphere from El Chichon volcanic vapors

    NASA Technical Reports Server (NTRS)

    Hofmann, D. J.; Rosen, J. M.; Gringel, W.

    1985-01-01

    It is pointed out that measurements of the vertical profiles of atmospheric condensation nuclei (CN) have been conducted since 1973. Studies with a new instrument revealed that the CN concentration undergoes a remarkable annual variation in the 30-km region characterized by a large increase in the late winter/early spring period with a subsequent decay during the remainder of the year. The event particles are observed to be volatile at 150 C, suggesting a sulfuric acid-water composition similar to that found in the normal 20 km aerosol layer. The development of about 10 to the 7th metric tons of sulfuric acid aerosol following the injection of sulfurous gases by El Chichon in April 1982, prompted Hofmann and Rosen (1983) to predict a very large CN event for 1983. The present investigation is concerned with the actual observation of the predicted event. Attention is given to the observation of a very large increase of what appear to be small sulfuric acid droplets at 30-km altitude in January 1983 over Laramie, WY, in January 1983.

  16. Models of lithosphere and asthenosphere anisotropic structure of the Yellowstone hot spot from shear wave splitting

    USGS Publications Warehouse

    Waite, G.P.; Schutt, D.L.; Smith, R.B.

    2005-01-01

    Teleseismic shear wave splitting measured at 56 continuous and temporary seismographs deployed in a 500 km by 600 km area around the Yellowstone hot spot indicates that fast anisotropy in the mantle is parallel to the direction of plate motion under most of the array. The average split time from all stations of 0.9 s is typical of continental stations. There is little evidence for plume-induced radial strain, suggesting that any contribution of gravitationally spreading plume material is undetectably small with respect to the plate motion velocity. Two stations within Yellowstone have splitting measurements indicating the apparent fast anisotropy direction (??) is nearly perpendicular to plate motion. These stations are ???30 km from stations with ?? parallel to plate motion. The 70?? rotation over 30 km suggests a shallow source of anisotropy; however, split times for these stations are more than 2 s. We suggest melt-filled, stress-oriented cracks in the lithosphere are responsible for the anomalous ?? orientations within Yellowstone. Stations southeast of Yellowstone have measurements of ?? oriented NNW to WNW at high angles to the plate motion direction. The Archean lithosphere beneath these stations may have significant anisotropy capable of producing the observed splitting. Copyright 2005 by the American Geophysical Union.

  17. Dispersal Patterns of Coastal Fish: Implications for Designing Networks of Marine Protected Areas

    PubMed Central

    Di Franco, Antonio; Gillanders, Bronwyn M.; De Benedetto, Giuseppe; Pennetta, Antonio; De Leo, Giulio A.; Guidetti, Paolo

    2012-01-01

    Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment) dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus) using otolith chemistry. At a large spatial scale (∼200 km) we investigated natal origin of fish and at a smaller scale (∼30 km) we assessed “site fidelity” (i.e. post-settlement dispersal until recruitment). Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply) to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ∼30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas. PMID:22355388

  18. Estimating dispersed and point source emissions of methane in East Anglia: results and implications

    NASA Astrophysics Data System (ADS)

    Harris, Neil; Connors, Sarah; Hancock, Ben; Jones, Pip; Murphy, Jonathan; Riddick, Stuart; Robinson, Andrew; Skelton, Robert; Manning, Alistair; Forster, Grant; Oram, David; O'Doherty, Simon; Young, Dickon; Stavert, Ann; Fisher, Rebecca; Lowry, David; Nisbet, Euan; Zazzeri, Guilia; Allen, Grant; Pitt, Joseph

    2016-04-01

    We have been investigating ways to estimate dispersed and point source emissions of methane. To do so we have used continuous measurements from a small network of instruments at 4 sites across East Anglia since 2012. These long-term series have been supplemented by measurements taken in focussed studies at landfills, which are important point sources of methane, and by measurements of the 13C:12C ratio in methane to provide additional information about its sources. These measurements have been analysed using the NAME InTEM inversion model to provide county-level emissions (~30 km x ~30 km) in East Anglia. A case study near a landfill just north of Cambridge was also analysed using a Gaussian plume model and the Windtrax dispersion model. The resulting emission estimates from the three techniques are consistent within the uncertainties, despite the different spatial scales being considered. A seasonal cycle in emissions from the landfill (identified by the isotopic measurements) is observed with higher emissions in winter than summer. This would be expected from consideration of the likely activity of methanogenic bacteria in the landfill, but is not currently represented in emission inventories such as the UK National Atmospheric Emissions Inventory. The possibility of assessing North Sea gas field emissions using ground-based measurements will also be discussed.

  19. Technical evaluation of proposed Ukrainian Central Radioactive Waste Processing Facility

    SciTech Connect

    Gates, R.; Glukhov, A.; Markowski, F.

    1996-06-01

    This technical report is a comprehensive evaluation of the proposal by the Ukrainian State Committee on Nuclear Power Utilization to create a central facility for radioactive waste (not spent fuel) processing. The central facility is intended to process liquid and solid radioactive wastes generated from all of the Ukrainian nuclear power plants and the waste generated as a result of Chernobyl 1, 2 and 3 decommissioning efforts. In addition, this report provides general information on the quantity and total activity of radioactive waste in the 30-km Zone and the Sarcophagus from the Chernobyl accident. Processing options are described that may ultimately be used in the long-term disposal of selected 30-km Zone and Sarcophagus wastes. A detailed report on the issues concerning the construction of a Ukrainian Central Radioactive Waste Processing Facility (CRWPF) from the Ukrainian Scientific Research and Design institute for Industrial Technology was obtained and incorporated into this report. This report outlines various processing options, their associated costs and construction schedules, which can be applied to solving the operating and decommissioning radioactive waste management problems in Ukraine. The costs and schedules are best estimates based upon the most current US industry practice and vendor information. This report focuses primarily on the handling and processing of what is defined in the US as low-level radioactive wastes.

  20. Resolution of the Scripps/NOAA Marine Gravity Field from satellite altimetry

    NASA Astrophysics Data System (ADS)

    Marks, Karen M.

    The July 1995 declassification of the entire Geosat GM satellite altimeter data set enabled a joint Scripps/NOAA effort to compute a new (version 7.2) marine gravity field on a 2-minute grid. This gravity field covers the world's oceans between 72°N and 72°S, and is derived from a combination of ERS-1 and Geosat GM and ERM data. An earlier NOAA Geosat-only gravity field solution was confined to the southern latitudes because the 1992 declassification was limited to GM data south of 30°S. A simple coherence analysis between accurately-navigated ship gravity profiles and comparable gravity profiles obtained from the gravity grids reveals that the Scripps/NOAA gravity field is coherent with ship gravity down to ˜≥ 23-30 km. This slight increase in resolution over the previous NOAA Geosat-only gravity field (short-wavelength resolution of ˜26-30 km) implies that the increased spatial coverage provided by the ERS-I altimeter, when combined with Geosat, improves the solution. Coherence analyses between satellite gravity and ship topography, and ship gravity and ship topography, show that even shorter wavelength gravity anomalies (˜13 km) are present in sea-surface measurements made by ship. Even so, the Scripps/NOAA marine gravity field does an excellent job of resolving most of the short-wavelength gravity anomalies covering the world’s oceans.

  1. Aftershocks of the western Argentina (Caucete) earthquake of 23 November 1977: some tectonic implications

    USGS Publications Warehouse

    Langer, C.J.; Bollinger, G.A.

    1988-01-01

    An aftershock survey, using a network of eight portable and two permanent seismographs, was conducted for the western Argentina (Caucete) earthquake (MS 7.3) of November 23, 1977. Monitoring began December 6, almost 2 weeks after the main shock and continued for 11 days. The data set includes 185 aftershock hypocenters that range in the depth from near surface to more than 30 km. The spatial distribution of those events occupied a volume of about 100 km long ??50 km wide ??30 km thick. The volumnar nature of the aftershock distribution is interpreted to be a result of a bimodal distribution of foci that define east- and west-dipping planar zones. Efforts to select which of those zones was associated with the causal faulting include special attention to the determination of the mainshock focal depth and dislocation theory modeling of the coseismic surface deformation in the epicentral region. Our focal depth (25-35 km) and modeling studies lead us to prefer an east-dipping plane as causal. A previous interpretation by other investigators used a shallower focal depth (17 km) and similar modeling calculations in choosing a west-dipping plane. Our selection of the east-dipping plane is physically more appealing because it places fault initiation at the base of the crustal seismogenic layer (rather than in the middle of that layer) which requires fault propagation to be updip (rather than downdip). ?? 1988.

  2. Shock Radiation Tests for Saturn and Uranus Entry Probes

    NASA Technical Reports Server (NTRS)

    Cruden, Brett A.; Bogdanoff, David W.

    2014-01-01

    This paper describes a test series in the Electric Arc Shock Tube at NASA Ames Research Center with the objective of quantifying shock-layer radiative heating magnitudes for future probe entries into Saturn and Uranus atmospheres. Normal shock waves are measured in Hydrogen/Helium mixtures (89:11 by mole) at freestream pressures between 13-66 Pa (0.1-0.5 Torr) and velocities from 20-30 km/s. No shock layer radiation is detected below 25 km/s, a finding consistent with predictions for Uranus entries. Between 25-30 km/s, radiance is quantified from the Vacuum Ultraviolet through Near Infrared, with focus on the Lyman-alpha and Balmer series lines of Hydrogen. Shock profiles are analyzed for electron number density and electronic state distribution. The shocks do not equilibrate over several cm, and distributions are demonstrated to be non-Boltzmann. Radiation data are compared to simulations of Decadal survey entries for Saturn and shown to be significantly lower than predicted with the Boltzmann radiation model.

  3. Vertical profiles of dust and ozone in the Martian atmosphere deduced from solar occultation measurements

    NASA Astrophysics Data System (ADS)

    Blamont, J. E.; Chassefiere, E.; Goutail, J. P.; Mege, B.; Nunes-Pinharanda, M.; Souchon, G.; Krasnopolsky, V. A.; Krysko, A. A.; Moroz, V. I.

    1991-02-01

    The vertical distribution of the ozone content and of the aerosols in the Martian atmosphere at the equinox and near the equator was studied with the aid of a biaxial pointing device, a microprocessor-controlled flat mirror of elliptical shape. An upper limit of 5 x 10 to the 7th mol/cu cm for ozone was obtained above an altitude of 30 km. For the aerosols, a semiquantitative distribution has been obtained between 10 and 50 km of altitude. The scale height is nearly equal to the atmospheric scale height in the 10-20 km region where mixing seems to predominate, and falls rapidly to a thickness of about 2 km at 30 km. In 10 percent of the occultations, a stratified haze has been detected between 40 and 50 km. The particle radius of cloud constituents is estimated and optical thickness per kilometer of these hazes at peak extinction are approximated. An eddy diffusion coefficient and a mixing ratio are estimated for clouds assumed to be at equilibrium.

  4. Atmosphere sounding by GPS radio occultation: First results from TanDEM-X and comparison with TerraSAR-X

    NASA Astrophysics Data System (ADS)

    Zus, Florian; Grunwaldt, Ludwig; Heise, Stefan; Michalak, Grzegorz; Schmidt, Torsten; Wickert, Jens

    2014-01-01

    On 21 June 2010 the TerraSAR-X satellite was joined by the TanDEM-X satellite. A Global Positioning System (GPS) radio occultation (RO) experiment using the twin satellites has been carried out to estimate the precision of GPS atmospheric soundings. For the Day Of Year (DOY) 330-336, 2011, we analyze phase and amplitude data recorded by GPS receivers separated by a few hundred meters in a low earth orbit and derive collocated atmospheric refractivity profiles. In the altitude range 10-20 km the standard deviation between TerraSAR-X and TanDEM-X refractivity does not exceed 0.15%. The standard deviation is rapidly increasing for lower and higher altitudes; close to the surface and at an altitude of 30 km the standard deviation reaches 0.8% and 0.5%, respectively. Systematic deviations between TerraSAR-X and TanDEM-X refractivity in the considered altitude range (0-30 km) are negligible. The results confirm the anticipated high precision of the GPS RO technique. However, the difference in the retrieved refractivity in the lower troposphere for different Open Loop (OL) signal tracking parameters, altered onboard TanDEM-X for DOY 49-55, 2012, calls for an in depth analysis. At the moment we can not exclude that a potential bias in the OL Doppler model introduces a bias in our retrieved refractivity at altitudes <8 km.

  5. Influences of Turbulent Reentry Plasma Sheath on Wave Scattering and Propagation

    NASA Astrophysics Data System (ADS)

    Liu, Zhiwei; Bao, Weimin; Li, Xiaoping; Shi, Lei; Liu, Donglin

    2016-06-01

    The randomness of turbulent reentry plasma sheaths can affect the propagation and scattering properties of electromagnetic waves. This paper developed algorithms to estimate the influences. With the algorithms and typical reentry data, influences of GPS frequency and Ka frequency are studied respectively. Results show that, in terms of wave scattering, the scattering loss caused by the randomness of the turbulent plasma sheath increases with the increase of the ensemble average electron density, ensemble average collision frequency, electron density fluctuation and turbulence integral scale respectively. Also the scattering loss is much smaller than the dielectric loss. The scattering loss of Ka frequency is much less than that of the GPS frequency. In terms of wave propagation, the randomness arouses the fluctuations of amplitude and phase of waves. The fluctuations change with altitudes that when the altitude is below 30 km, fluctuations increase with altitude increasing, and when the altitude is above 30 km, fluctuations decrease with altitude increasing. The fluctuations of GPS frequency are strong enough to affect the tracking, telemetry, and command at appropriate conditions, while the fluctuations of Ka frequency are much more feeble. This suggests that the Ka frequency suffers less influences of the randomness of a turbulent plasma sheath. supported by the National Basic Research Program of China (No. 2014CB340205) and National Natural Science Foundation of China (Nos. 61301173 and 61473228)

  6. Shear wave velocity structure of the lower crust in southern Africa: Evidence for compositional heterogeneity within Archaean and Proterozoic terrains

    NASA Astrophysics Data System (ADS)

    Kgaswane, Eldridge M.; Nyblade, Andrew A.; Juliã, Jordi; Dirks, Paul H. G. M.; Durrheim, Raymond J.; Pasyanos, Michael E.

    2009-12-01

    The nature of the lower crust across the southern African shield has been investigated by jointly inverting receiver functions and Rayleigh wave group velocities for 89 broadband seismic stations located in Botswana, South Africa and Zimbabwe. For large parts of both Archaean and Proterozoic terrains, the velocity models obtained from the inversions show shear wave velocities ≥4.0 km/s below ˜20-30 km depth, indicating a predominantly mafic lower crust. However, for much of the Kimberley terrain and adjacent parts of the Kheis Province and Witwatersrand terrain in South Africa, as well as for the western part of the Tokwe terrain in Zimbabwe, shear wave velocities of ≤3.9 km/s are found below ˜20-30 km depth, indicating an intermediate-to-felsic lower crust. The areas of intermediate-to-felsic lower crust in South Africa coincide with regions where Ventersdorp rocks have been preserved, suggesting that the more evolved composition of the lower crust may have resulted from crustal reworking and extension during the Ventersdorp tectonomagmatic event at c. 2.7 Ga.

  7. Model testing using Chernobyl data: III. Atmospheric resuspension of radionuclides in Ukrainian regions impacted by Chernobyl fallout

    SciTech Connect

    Garger, E.K.; Hoffman, F.O.; Miller, C.W.

    1996-01-01

    The {open_quotes}Resuspension{close_quotes} scenario is designed to test models for atmospheric resuspension of radionuclides from contaminated soils. Resuspension can be a secondary source of contamination after a release has stopped, as well as a source of contamination for people and areas not exposed to the original release. The test scenario describes three exposure situations: (1) locations within the highly contaminated 30-km zone at Chernobyl, where exposures to resuspended material are probably dominated by local processes; (2) an urban area (Kiev) outside the 30-km zone, where local processes include extensive vehicular traffic; and (3) a location 40 to 60 km west of the Chernobyl reactor, where upwind sources of contamination are important. Input data include characteristics of the {sup 137}Cs ground contamination around specific sites, climatological data for the sites, characteristics of the terrain and topography, and locations of the sampling sites. Predictions are requested for average air concentrations of {sup 137}Cs at specified locations due to resuspension of Chernobyl fallout and for specified resuspension factors and rates. Test data (field measurements) are available for all endpoints. 9 refs., 4 figs., 11 tabs.

  8. Information theory lateral density distribution for Earth inferred from global gravity field

    NASA Technical Reports Server (NTRS)

    Rubincam, D. P.

    1981-01-01

    Information Theory Inference, better known as the Maximum Entropy Method, was used to infer the lateral density distribution inside the Earth. The approach assumed that the Earth consists of indistinguishable Maxwell-Boltzmann particles populating infinitesimal volume elements, and followed the standard methods of statistical mechanics (maximizing the entropy function). The GEM 10B spherical harmonic gravity field coefficients, complete to degree and order 36, were used as constraints on the lateral density distribution. The spherically symmetric part of the density distribution was assumed to be known. The lateral density variation was assumed to be small compared to the spherically symmetric part. The resulting information theory density distribution for the cases of no crust removed, 30 km of compensated crust removed, and 30 km of uncompensated crust removed all gave broad density anomalies extending deep into the mantle, but with the density contrasts being the greatest towards the surface (typically + or 0.004 g cm 3 in the first two cases and + or - 0.04 g cm 3 in the third). None of the density distributions resemble classical organized convection cells. The information theory approach may have use in choosing Standard Earth Models, but, the inclusion of seismic data into the approach appears difficult.

  9. Multiple-Aperture-Based Solar Seeing Profiler

    NASA Astrophysics Data System (ADS)

    Ren, Deqing; Zhao, Gang; Zhang, Xi; Dou, Jiangpei; Chen, Rui; Zhu, Yongtian; Yang, Feng

    2015-09-01

    Characterization of day-time atmospheric turbulence profiles up to 30 km above the telescope is crucial for designs and performance estimations of future solar multiconjugate adaptive optics (MCAO) systems. Recently, the S-DIMM+ method has been successfully used to measure the vertical profile of turbulence. However, to measure profile up to 30 km employing the S-DIMM+ method, a telescope with a diameter of at least 1.0 m is needed, which restricts the usage of S-DIMM+, since large telescopes are scarce and their time is limited. To solve this problem, we introduce the multiple-aperture seeing profiler (MASP), which consists of two portable small telescopes instead of a single large aperture. Numerical simulations are carried out to evaluate the performance of MASP. We find that for one layer case, MASP can retrieve the seeing with error ~5% using 800 frames of wavefront sensor (WFS) data, which is quite similar to the results of a telescope with diameter of 1120 mm. We also simulate profiles with four turbulence layers, and find that our MASP can effectively retrieve the strengths and heights of the four turbulence layers. Since previous measurements at Big Bear Solar Observatory showed that day-time turbulence profile typically consists of four layers, the MASP we introduced is sufficient for actual seeing measurement.

  10. Analyses of Bed Topography and Hyporheic Exchange Using a High-Resolution Bathymetric Lidar

    NASA Astrophysics Data System (ADS)

    McKean, J. A.; Tonina, D.; Marzadri, A.; Tiedemann, M.

    2011-12-01

    The hyporheic zone is a critical stream bed ecotone used by microorganisms, macroinvertebrates and spawning fish. Hyporheic exchange often results from differences in the channel near-bed total pressures as they vary in response to interactions between the surface flow and bed topography. The elevation head and the static and dynamic pressure heads are all sensitive to the spacing and amplitude of bed forms. We used a high resolution bathymetric lidar to describe the morphology of 30 km of a mountain river, and then defined the frequency and amplitude of bed forms in the channel with 1D wavelet transforms. We also mapped spatial variations in other important channel attributes, such as width and slope, using the River Bathymetry Toolkit (RBT), a freeware Arc-based GIS toolkit that automatically extracts hydrologic geometry and habitat information from high resolution DEMs of streams (http://www.fs.fed.us/rm/boise/AWAE/projects/river_bathymetry_toolkit.shtml). The wavelet transforms and geometry patterns were exploited to stratify the 30 km domain into hypothesized areas of consistent hyporheic exchange. The accuracy of our form-based hyporheic stratification is being tested with fluid dynamic models of surface and groundwater flow. The biological significance of the strata is also being evaluated by comparison with field samples of macroinvertebrate populations.

  11. Analysis of geophysical well logs obtained in the State 2-14 borehole, Salton Sea geothermal area, California

    USGS Publications Warehouse

    Paillet, Frederick L.; Morin, R.H.

    1988-01-01

    A complete suite of conventional geophysical well logs was obtained in the upper part of a 3220-m-deep borehole drilled into geothermally altered alluvial sediments on the southeastern edge of the Salton Sea. Geophysical logs obtained in the State 2-14 borehole indicate that neutron porosity, gamma-gamma, and deep-induction logs provide useful information on lithologic trends with depth. The natural gamma log contains almost continuous, high-frequency fluctuations that obscure lithologic trends and that may be related to recent radioisotope redistribution and departure from radiometric equilibrium. Acoustic transit time logs give unrealistically low in situ compressional velocities ranging from 1.8 to 3.0 km/s, whereas acoustic waveform logs indicate that sediment compressional velocities range from less than 3.0 km/s shallower than 1000 m in depth to almost 5.0 km/s at depths greater than 2000 m. Analyses indicate that most log values lie between two lithologic end points: an electrically conductive claystone with moderate neutron porosity, but no effective porosity, and an electrically nonconductive, fully cemented siltstone that has small but finite porosity. -from Authors

  12. Turbulent transport and deposition of the Ito pyroclastic flow: Determinations using anisotropy of magnetic susceptibility

    SciTech Connect

    Baer, E.M.; Fisher, R.V.; Fuller, M.; Valentine, G.

    1997-10-01

    The Ito pyroclastic flow erupted about 22,000 years ago from Aira caldera in southern Kyushu, Japan. Flow directions were determined by anisotropy of magnetic susceptibility (AMS), which measured the preferential alignment of magnetite microphenocrysts, usually {le}0.25mm in diameter. The microphenocrysts are aligned with the long axis of the clasts during strain and fracture in the vent. The grains are then deposited parallel to the flow direction with an imbrication. There is no evidence of rolling of clasts or nonflow parallel lineations, and thus AMS can be used to determine flow directions that occurred immediately before deposition. Beyond 30 km from the center of the caldera, flow directions were predominantly down paleogradient, indicating expanded flow and that the depositional system was gravity driven and largely decoupled from the transport system. Within 30 km, measured flow directions are random, indicating that sedimentation occurred from a depositional system that was closely coupled to the turbulent transport system. Individual flow directions at all sites except one varied more than the analytical error, demonstrating that a variety of flow directions existed even within a small area of the flow. This implies that the depositional system was turbulent.{copyright} 1997 American Geophysical Union

  13. Heat flow and thermal processes in the Jornada delMuerto, New Mexico

    NASA Technical Reports Server (NTRS)

    Reiter, M.

    1985-01-01

    Most heat flow data in rifts are uncertain largely because of hydrologic disturbances in regions of extensive fracturing. Estimates of heat flow in deep petroleum tests within a large basin of the Rio Grande rift, which has suffered little syn-rift fracturing, may begin to provide clearer insight into the relationships between high heat flow and crustal thinning processes. The Jornada del Muerto is a large basin located in the Rio Grande rift of south central New Mexico. The region of interest within the Jornada del Muerto is centered about 30 km east of the town of Truth or Consequences, and is approximately 60 km north-south by 30 km east-west. High heat flows are estimated for the region. Values increase from about 90 mWm(-2) in the northern part of the study area to about 125 mWm(-2) in the southern part. These high heat flows are rather enigmatic because in the immediate vicinities of the sites there is little evidence of Cenozoic volcanism or syn-rift extensional tectonics. It is suggested that the geothermal anomaly in the southern Jornada del Muerto (approx. 125 to approx. 95 mWm(-2) results from some type of mass movement-heat transfer mechanism operating in the crust just below the elastic layer. This conclusion is consistent with the geologic and geophysical data which describe a thin crust, apparently devoid of features indicative of extensional-tectonics in the upper part of the lastic crust.

  14. Implications of extinction due to meteoritic smoke in the upper stratosphere

    NASA Astrophysics Data System (ADS)

    Neely, Ryan R., III; English, Jason M.; Toon, Owen B.; Solomon, Susan; Mills, Michael; Thayer, Jeffery P.

    2011-12-01

    Recent optical observations of aerosols in the upper stratosphere and mesosphere show significant amounts of extinction at altitudes above about 40 km where the stratospheric sulfate aerosol layer ends. Recent modeling of this region reveals that meteoritic smoke settling from the mesosphere and its interaction with the upper part of the sulfate aerosol layer is the origin of the observed extinction. Extinction in this region has major implications for the interpretation and analysis of several kinds of aerosol data (satellite and lidar). We compare observations from the SAGE II satellite and from NOAA's lidar located at Mauna Loa, Hawaii to extinction profiles derived from the Whole Atmosphere Community Climate Model (WACCM) coupled with the Community Aerosol and Radiation Model for Atmospheres (CARMA). Our results show that a major source of extinction exists in the region above about 30 km that must be addressed by all remote sensing instruments that have traditionally used the stratosphere above about 30 km as an aerosol free region to estimate the molecular component of their total extinction. It is also shown that meteoritic smoke not only contributes to but also becomes the dominant source of aerosol extinction above 35 km and poleward of 30 degrees in latitude, as well as above 40 km in the tropics. After addressing the concerns described here, current and past observations of this region could be reanalyzed to further our understanding of meteoritic dust in the upper stratosphere.

  15. Development and validation of satellite based estimates of surface visibility

    NASA Astrophysics Data System (ADS)

    Brunner, J.; Pierce, R. B.; Lenzen, A.

    2015-10-01

    A satellite based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5% for classifying Clear (V ≥ 30 km), Moderate (10 km ≤ V < 30 km), Low (2 km ≤ V < 10 km) and Poor (V < 2 km) visibilities and shows the most skill during June through September, when Heidke skill scores are between 0.2 and 0.4. We demonstrate that the aerosol (clear sky) component of the GOES-R ABI visibility retrieval can be used to augment measurements from the United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network, and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.

  16. Preliminary validation of refractivity from a new radio occultation sounder GNOS/FY-3C

    NASA Astrophysics Data System (ADS)

    Liao, M.; Zhang, P.; Yang, G. L.; Bi, Y. M.; Liu, Y.; Bai, W. H.; Meng, X. G.; Du, Q. F.; Sun, Y. Q.

    2015-09-01

    As a new member of space-based radio occultation sounder, the GNOS (Global Navigation Satellite System Occultation Sounder) mounted on FY-3C has been carrying out the atmospheric sounding since 23 September 2013. GNOS takes a daily measurement up to 800 times with GPS (Global Position System) and Chinese BDS (BeiDou navigation satellite) signals. The refractivity profiles from GNOS are compared with the co-located ECMWF (European Centre for Medium-Range Weather Forecasts) analyses in this paper. Bias and standard deviation have being calculated as the function of altitude. The mean bias is about 0.2 % from the near surface to 35 km. The average standard deviation is within 2 % while it is down to about 1 % in the range 5-30 km where best soundings are usually made. To evaluate the performance of GNOS, COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) and GRAS/METOP-A (GNSS Receiver for Atmospheric Sounding) data are also compared to ECMWF analyses as the reference. The results show that GNOS/FY-3C meets the requirements of the design well. It possesses a sounding capability similar to COSMIC and GRAS in the vertical range of 0-30 km, though it needs improvement in higher altitude. Generally, it provides a new data source for global NWP (numerical weather prediction) community.

  17. The offshore East African Rift System: Structural framework at the toe of a juvenile rift

    NASA Astrophysics Data System (ADS)

    Franke, Dieter; Jokat, Wilfried; Ladage, Stefan; Stollhofen, Harald; Klimke, Jennifer; Lutz, Ruediger; Mahanjane, Estevão. Stefane; Ehrhardt, Axel; Schreckenberger, Bernd

    2015-10-01

    The Cenozoic East African Rift System (EARS) extends from the Red Sea to Mozambique. Here we use seismic reflection and bathymetric data to investigate the tectonic evolution of the offshore branch of the EARS. The data indicate multiple and time transgressive neotectonic deformations along ~800 km of the continental margin of northern Mozambique. We observe a transition from a mature rift basin in the north to a juvenile fault zone in the south. The respective timing of deformation is derived from detailed seismic stratigraphy. In the north, a ~30 km wide and more than 150 km long, N-S striking symmetric graben initiated as half-graben in the late Miocene. Extension accelerated in the Pliocene, causing a continuous conjugate border fault and symmetric rift graben. Coevally, the rift started to propagate southward, which resulted in a present-day ~30 km wide half-graben, approximately 200 km farther south. Since the Pleistocene, the rift has continued to propagate another ~300 km, where the incipient rift is reflected by subrecent small-scale normal faulting. Estimates of the overall brittle extension of the matured rift range between 5 and 12 km, with an along-strike southward decrease of the extension rate. The offshore portion of the EARS evolves magma poor, similar to the onshore western branch. The structural evolution of the offshore EARS is suggested to be related to and controlled by differing inherited lithospheric fabrics. Preexisting fabrics may not only guide and focus extension but also control rift architecture.

  18. Tiny Ultraviolet Polarimeter for Earth Stratosphere from Space Investigation

    NASA Astrophysics Data System (ADS)

    Nevodovskyi, P. V.; Morozhenko, O. V.; Vidmachenko, A. P.; Ivakhiv, O.; Geraimchuk, M.; Zbrutskyi, O.

    2015-09-01

    One of the reasons for climate change (i.e., stratospheric ozone concentrations) is connected with the variations in optical thickness of aerosols in the upper sphere of the atmosphere (at altitudes over 30 km). Therefore, aerosol and gas components of the atmosphere are crucial in the study of the ultraviolet (UV) radiation passing upon the Earth. Moreover, a scrupulous study of aerosol components of the Earth atmosphere at an altitude of 30 km (i.e., stratospheric aerosol), such as the size of particles, the real part of refractive index, optical thickness and its horizontal structure, concentration of ozone or the upper border of the stratospheric ozone layer is an important task in the research of the Earth climate change. At present, the Main Astronomical Observatory of the National Academy of Sciences (NAS) of Ukraine, the National Technical University of Ukraine "KPI"and the Lviv Polytechnic National University are engaged in the development of methodologies for the study of stratospheric aerosol by means of ultraviolet polarimeter using a microsatellite. So fare, there has been created a sample of a tiny ultraviolet polarimeter (UVP) which is considered to be a basic model for carrying out space experiments regarding the impact of the changes in stratospheric aerosols on both global and local climate.

  19. The mean ozone distribution from several series of rocket sounding to 52 km at latitudes from 58 deg S to 64 deg N

    NASA Technical Reports Server (NTRS)

    Krueger, A. J.

    1973-01-01

    The results of 21 rocket flights of Arcas optical ozonesondes were combined to produce estimates of the mean ozone distribution and its variability; these estimates apply to a broad range of latitudes. The flights were launched from sites near the equator to 58 S and to 64 N, in the years from 1965 to 1971. The local-noon mean ozone densities in molecules/cubic centimeter are 7.0 to the 10th power at 50 km, 6.7 x 10 to the 11th power at 40 km, 3.1 x 10 to the 12th power at 30 km, and 3.1 x 10 to the 12th power at 20 km. The range of observed densities is about + or - 30 percent of the mean value at 50 km; + or 40 percent at 40 km; + or - 40 percent at 30 km; and +200 percent, -66 percent at 20 km. The variabilities in this set of observations are much smaller than those indicated by previous measurements.

  20. Regional Characterization of Tokyo Metropolitan area using a highly-dense seismic network (MeSO-net)

    NASA Astrophysics Data System (ADS)

    Hirata, Naoshi; Nakagawa, Shigeki; Sakai, Shin'ichi; Panayotopoulos, Yannis; Ishikawa, Masahiro; Ishibe, Takeo; Kimura, Hisanori; Honda, Ryou

    2015-04-01

    We have developed a dense seismic network, MeSO-net (Metropolitan Seismic Observation network), which consists of about 300 seismic stations, since 2007 in the greater Tokyo urban region(Hirata et al., 2009). Using MeSO-net data, we obtain P- and S- wave velocity tomograms (Nakagawa et al., 2010) and Qp, Qs tomograms (Panayotopoulos et al., 2014) which show a clear image of Philippine Sea Plate (PSP) and PAcific Plate (PAP). A depth to the top of PSP, 20 to 30 km beneath northern part of Tokyo bay, is about 10 km shallower than previous estimates based on the hypocenter distribution (Ishida, 1992). Based on elastic wave velocities of rocks and minerals, we constructed a petrologic model. The Vp steps in subducting Izu forearc crust occurs at a depth of 30km (blueschist or greenschist to garnet amphibolite transformation) and a depth of 50km (garnet amphibolite to eclogite transformation). Both temperatures are estimated to be 500 and 600 degree C, respectively. The high Vp/Vs anomaly (>1.9) implies large amounts of fluid H2O released by garnet amphibolite to eclogite dehydration reactions. This study is supported by MEXT Japan under the Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters.

  1. Development and validation of satellite-based estimates of surface visibility

    NASA Astrophysics Data System (ADS)

    Brunner, J.; Pierce, R. B.; Lenzen, A.

    2016-02-01

    A satellite-based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5 % for classifying clear (V ≥ 30 km), moderate (10 km ≤ V < 30 km), low (2 km ≤ V < 10 km), and poor (V < 2 km) visibilities and shows the most skill during June through September, when Heidke skill scores are between 0.2 and 0.4. We demonstrate that the aerosol (clear-sky) component of the GOES-R ABI visibility retrieval can be used to augment measurements from the United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.

  2. Range resolution dependence of VHF radar returns from clear-air turbulence and precipitation

    NASA Astrophysics Data System (ADS)

    Chu, Y.-H. Y.-H.; Su, C.-L.

    1999-06-01

    With employing 1.5 h of the data observed by the Chung-Li VHF radar, the range resolution dependences of the VHF backscatter from refractivity fluctuation and precipitation are investigated in this article. It indicates that the atmospheric layer structure of refractivity seems to play a role in governing the range resolution dependence of clear-air turbulent echoes. Observations shows that the VHF clear-air echo power ratios for 4 to 2 μs pulse lengths are close to 3 dB in the middle or bottom side of the layer, while the ratios are significantly greater than 3 dB in the top side of the layer. The analysis of the precipitation echo power ratio for 4 to 2 ms pulse lengths shows that basically the ratios above 3.0 km are close to 3 dB, but enormously smaller than 3 dB below 3.0 km. The feature of extraordinarily small echo power ratios below 3.0 km is also observed for the radar returns from refractivity turbulence. The radar recovery effect is thought to be a primary factor responsible for the severe diminution of the echo power ratios at the lower altitudes. In addition, statistical analysis reveals that the range resolution effect on the first and second moments of the Doppler spectra for the radar echoes from clear-air turbulence and precipitation is insignificant and negligible. The dependences of the coefficient A and power B in the power-law approximation Vt=APBr to the terminal velocity Vt and range-corrected echo power Pr are examined theoretically and experimentally. The results show that the coefficient A (powers B) is inversely (positively) proportional to the range resolution, in a good agreement with the observations. Because of the strong dependence of coefficient A and power B on the radar pulse width, it suggests that great caution should be taken in comparing the power-law expressions Vt=APBr established from the radar returns obtained with different range resolutions.

  3. Evaluation of tropical channel refinement using MPAS-A aquaplanet simulations

    DOE PAGESBeta

    Martini, Matus N.; Gustafson, Jr., William I.; O'Brien, Travis A.; Ma, Po -Lun

    2015-09-13

    Climate models with variable-resolution grids offer a computationally less expensive way to provide more detailed information at regional scales and increased accuracy for processes that cannot be resolved by a coarser grid. This study uses the Model for Prediction Across Scales–Atmosphere (MPAS22A), consisting of a nonhydrostatic dynamical core and a subset of Advanced Research Weather Research and Forecasting (ARW-WRF) model atmospheric physics that have been modified to include the Community Atmosphere Model version 5 (CAM5) cloud fraction parameterization, to investigate the potential benefits of using increased resolution in an tropical channel. The simulations are performed with an idealized aquaplanet configurationmore » using two quasi-uniform grids, with 30 km and 240 km grid spacing, and two variable-resolution grids spanning the same grid spacing range; one with a narrow (20°S–20°N) and one with a wide (30°S–30°N) tropical channel refinement. Results show that increasing resolution in the tropics impacts both the tropical and extratropical circulation. Compared to the quasi-uniform coarse grid, the narrow-channel simulation exhibits stronger updrafts in the Ferrel cell as well as in the middle of the upward branch of the Hadley cell. The wider tropical channel has a closer correspondence to the 30 km quasi-uniform simulation. However, the total atmospheric poleward energy transports are similar in all simulations. The largest differences are in the low-level cloudiness. The refined channel simulations show improved tropical and extratropical precipitation relative to the global 240 km simulation when compared to the global 30 km simulation. All simulations have a single ITCZ. Furthermore, the relatively small differences in mean global and tropical precipitation rates among the simulations are a promising result, and the evidence points to the tropical channel being an effective method for avoiding the extraneous numerical artifacts seen in

  4. Perceived environmental and health risks of nuclear energy in Taiwan after Fukushima nuclear disaster.

    PubMed

    Ho, Jung-Chun; Lee, Chiao-Tzu Patricia; Kao, Shu-Fen; Chen, Ruey-Yu; Ieong, Marco C F; Chang, Hung-Lun; Hsieh, Wan-Hua; Tzeng, Chun-Chiao; Lu, Cheng-Fung; Lin, Suei-Loong; Chang, Peter Wushou

    2014-12-01

    After the nuclear disaster in Fukushima in Japan in 2011, a nation-wide survey using a standardized self-administered questionnaire was conducted in Taiwan, with a sample size of 2,742 individuals including the residents who live within and beyond 30 km from a nuclear power plant (NPP), to evaluate the participants' perceived nuclear risk in comparison with their perceived risks from selected environmental hazards and human behaviors. The three leading concerns of nuclear energy were "nuclear accidents (82.2%)," "radioactive nuclear waste disposal (76.9%)" and "potential health effects (73.3%)." Respondents (77.6%) perceived a higher relative risk of cancer incidence for those who live within 30 km from an NPP than those who live outside 30 km from an NPP. All the participants had a higher risk perception of death related to "nuclear power operation and nuclear waste" than cigarette smoking, motorcycling, food poisoning, plasticizer poisoning and traveling by air. Moreover, the residents in Gongliao where the planned fourth NPP is located had a significantly higher perceived risk ratio (PRR) of cancer incidence (adjusted odd ratio (aOR)=1.84, p value=0.017) and perceived risk of death (aOR=4.03, p value<0.001) related to nuclear energy. The other factors such as female gender (aOR/p value, 1.25/0.026 and 1.34/0.001 respectively), lower education levels (aOR/p value: 1.31/0.032; 2.03/<0.001) and the participants' concerns about nuclear accidents (aOR/p value: 1.33/0.022; 1.51/<0.001) and potential health effects (aOR/ p value: 2.95/ <0.001; 2.56/<0.001) were found to be commonly associated with the PRRs of "cancer incidence" and "perceived risk of death" related to nuclear energy, respectively. In addition, the respondents' concerns about nuclear waste disposal and possible eco-environmental damage made significant contributions (aOR/ p value: 1.39/ 0.001; 1.40/<0.001) to predict their perceived risk of death related to nuclear power. These factors are considered as

  5. The crustal structure from the Altai Mountains to the Altyn Tagh fault, northwest China

    USGS Publications Warehouse

    Wang, Y.; Mooney, W.D.; Yuan, X.; Coleman, R.G.

    2003-01-01

    We present a new crustal section across northwest China based on a seismic refraction profile and geologic mapping. The 1100-km-long section crosses the southern margin of the Chinese Altai Mountains, Junggar Accretional Belt and eastern Junggar basin, easternmost Tianshan Mountains, and easternmost Tarim basin. The crustal velocity structure and Poisson's ratio (??), which provide a constraint on crustal composition, were determined from P and S wave data. Despite the complex geology, the crustal thickness along the entire profile is nearly uniform at 50 km. The thickest crust (56 km) occurs at the northern end of the profile beneath the Altai Mountains and the thinnest (46 km) crust is beneath the Junggar basin. Beneath surficial sediments, the crust is found to have three layers with P wave velocities (Vp) of 6.0-6.3, 6.3-6.6, and 6.9-7.0 km/s, respectively. The southern half of the profile, including the eastern Tianshan Mountains and eastern margin of the Tarim basin, shows low P wave velocities and ?? = 0.25 to a depth of 30 km, which suggests a quartz-rich, granitic upper crustal composition. The northern half of the profile below the Altai Mountains and Junggar Accretional Belt has a higher Poisson's ratio of ?? = 0.26-0.27 to a depth of 30 km, indicative of an intermediate crustal composition. The entire 1100-km-long profile is underlain by a 15-30 km thick high velocity (6.9-7.0 km/s; ?? = 0.26-0.28) lower-crustal layer that we interpret to have a bulk composition of mafic granulite. At the southern end of the profile, a 5-km-thick midcrustal low-velocity layer (Vp = 5.9 km/s, ?? = 0.25) underlies the Tianshan and the region to the south, and may be indicative of a near-horizontal detachment interface. Pn velocities are ???7.7-7.8 km/s between the Tianshan and the Junggar basin, and ???7.9-8.0 km/s below the Altai Mountains and eastern margin of the Tarim basin. We interpret the consistent three-layer stratification of the crust to indicate that the crust

  6. Quantitative Estimates of the Numbers of Casualties to be Expected due to Major Earthquakes Near Megacities

    NASA Astrophysics Data System (ADS)

    Wyss, M.; Wenzel, F.

    2004-12-01

    Defining casualties as the sum of the fatalities plus injured, we use their mean number, as calculated by QUAKELOSS (developed by Extreme Situations Research Center, Moscow) as a measure of the extent of possible disasters due to earthquakes. Examples of cities we examined include Algiers, Cairo, Istanbul, Mumbai and Teheran, with populations ranging from about 3 to 20 million. With the assumption that the properties of the building stock has not changed with time since 1950, we find that the number of expected casualties will have increased about 5 to 10 fold by the year 2015. This increase is directly proportional to the increase of the population. For the assumed magnitude, we used M7 and M6.5 because shallow earthquakes in this range can occur in the seismogenic layer, without rupturing the surface. This means, they could occur anywhere in a seismically active area, not only along known faults. As a function of epicentral distance the fraction of casualties of the population decrease from about 6% at 20 km, to 3% at 30 km and 0.5% at 50 km, for an earthquake of M7. At 30 km distance, the assumed variation of the properties of the building stock from country to country give rise to variations of 1% to 5% for the estimate of the percent of the population that become casualties. As a function of earthquake size, the expected number of casualties drop by approximately an order of magnitude for an M6.5, compared to an M7, at 30 km distance. Because the computer code and database in QUAKELOSS are calibrated based on about 1000 earthquakes with fatalities, and verified by real-time loss estimates for about 60 cases, these results are probably of the correct order of magnitude. However, the results should not be taken as overly reliable, because (1) the probability calculations of the losses result in uncertainties of about a factor of two, (2) the method has been tested for medium size cities, not for megacities, and (3) many assumptions were made. Nevertheless, it is

  7. Seismicity of the 24 May 2014 Mw 7.0 Aegean Sea earthquake sequence along the North Aegean Trough

    NASA Astrophysics Data System (ADS)

    Görgün, Ethem; Görgün, Burçak

    2015-11-01

    The northern Aegean Sea was hit by a large size (Mw = 7.0) earthquake on 2014 May 24. Centroid moment tensor solutions for 40 events with moment magnitudes (Mw) between 3.3 and 7.0 are computed by applying a waveform inversion method on data from the Turkish and Greek broadband seismic networks. The time span of data covers the period between 2014 May 24 and 2014 June 26. The mainshock is a shallow focus strike-slip event at a depth of 15 km. Focal depths of aftershocks range from 6 to 30 km. The seismic moment (Mo) of the mainshock is estimated as 4.60 × 1019 Nm. The calculated rupture duration of the North Aegean Sea mainshock is 40 s. The focal mechanisms of the aftershocks are mainly strike-slip faulting with a minor normal component. The geometry of focal mechanisms reveals a strike-slip faulting regime with NE-SW trending direction of T-axis in the entire activated region. A stress tensor inversion of focal mechanism data is performed to acquire a more accurate picture of the northern Aegean Sea stress field along the North Aegean Trough. The stress tensor inversion results indicate a predominant strike-slip stress regime with a NW-SE oriented maximum principal compressive stress (σ1). In the development of the North Aegean Trough in Aegean Sea is in good agreement with the resolved stress tensors. With respect the newly determined focal mechanisms, the effect of the propagating of the North Anatolian Fault into Aegean Sea is very clearly pronounced. According to high-resolution hypocenter relocation of the North Aegean Sea seismic sequence, three main clusters are revealed. The aftershock activity in the observation period between 2014 May 24 and 2014 July 31 extends from the mainshock cluster from NE to the SW direction. Seismic cross-sections indicate that a complex pattern of the hypocenter distribution with the activation of seventeen segments. The eastern cluster is associated with a fault plane trending mainly ENE-WSW and dipping vertical, while the

  8. Alpha Ridge: Oceanic or Continental Crust? Constraints from Crustal Thickness Mapping using Gravity Inversion

    NASA Astrophysics Data System (ADS)

    Kusznir, N. J.; Alvey, A.

    2010-12-01

    The ocean basins of the Arctic formed during the Late Jurassic, Cretaceous and Tertiary as a series of small distinct ocean basins leading to a complex distribution of oceanic crust, thinned continental crust and rifted continental margins. The structure and origin of the Alpha and Mendeleev Ridges within the Amerasia Basin are contentious; possibilities include thick oceanic crust formed by ocean ridge - mantle plume interaction, micro-continents or thinned continental crust with mantle plume volcanic addition. We use gravity inversion, incorporating a lithosphere thermal gravity anomaly correction, to map Moho depth, crustal thickness and continental lithosphere thinning factor for the Amerasia Basin in order to determine the distribution of oceanic and continental lithosphere and the ocean-continent transition location. Data used in the gravity inversion are gravity data from the NGA (U) Arctic Gravity Project, IBCAO bathymetry and sediment thickness from Laske et al. (1997). Our gravity inversion predicts thin crust (5-10 km thickness) and high continental lithosphere thinning factors in the Makarov, Podvodnikov, Nautilus and Canada Basins consistent with these basins being oceanic or highly thinned continental crust. Larger crustal thicknesses, in the range 20-30 km, are predicted for the Alpha, Mendeleev and Lomonosov Ridges. Moho depths predicted by gravity inversion compare well with estimates from the TransArctica-Arctica seismic profiles. Moho depths from the gravity inversion are dependent on the age of oceanic lithosphere and continental breakup because of the lithosphere thermal gravity anomaly correction; these ages are uncertain for the Amerasia Basin. Gravity inversion sensitivities to break-up ages between 150 Ma (late Jurassic Triassic) and 60 Ma (early Tertiary) have been examined. Alpha Ridge has in its centre a crustal thickness of 25-30 km and possesses sharp angular edges. While Alpha Ridge has been compared with Iceland for structure and

  9. Medical relief activities, medical resourcing, and inpatient evacuation conducted by Nippon Medical School due to the Fukushima Daiichi Nuclear Power Plant accident following the Great East Japan Earthquake 2011.

    PubMed

    Koyama, Atsushi; Fuse, Akira; Hagiwara, Jun; Matsumoto, Gaku; Shiraishi, Shinichiro; Masuno, Tomohiko; Miyauchi, Masato; Kawai, Makoto; Yokota, Hiroyuki

    2011-01-01

    On March 11, 2011, after the Great East Japan Earthquake and tsunami, the government declared a nuclear emergency following damage to the Fukushima Daiichi Nuclear Power Plant. A second hydrogen explosion occurred on March 14 at the plant's No. 3 reactor and injured 11 people. At that time the prime minister urged people living 20 to 30 km from the Daiichi plant to stay indoors. Under these circumstances, many residents of Iwaki City, which was largely outside the 30-km zone, left the city, making it difficult to get supplies to the remaining residents. The only transportation route open for supplies and medical resources was roads, and many drivers feared the rumor that the city was contaminated by radioactive materials and, so, refused to go there. Nippon Medical School (NMS) heard that medical resources were running short at Iwaki Kyoritsu Hospital, which requested water, medications, food, fuel (gasoline), medical support, and the evacuation of 300 inpatients. As a first step, NMS decided to evaluate the situation at the hospital and, on March 16, the director of the NMS Advanced Emergency Center visited the hospital and helped provide triage for about 200 patients. Critically ill patients receiving ventilatory support were given priority for evacuation because they would be most at risk of not being able to evacuate should the Japanese government order an immediate evacuation of the city. We tried to evacuate the inpatients via an official framework, such as the Disaster Medical Assistance Team (DMAT), but DMAT could not support this mission because this hospital was not within the 30-km evacuation zone. Moreover, the Iwaki City government could not support the evacuation efforts because they were fearful of the rumor that Iwaki was contaminated by radioactive material. Ultimately, we realized that we had to conduct the mission ourselves and, so, contacted our colleagues in the Tokyo metropolitan area to prepare enough hospital beds. We evacuated 15 patients

  10. Sensitivity of the GCM driven summer monsoon simulations to cumulus parameterization schemes in nested RegCM3

    NASA Astrophysics Data System (ADS)

    Sinha, P.; Mohanty, U. C.; Kar, S. C.; Dash, S. K.; Kumari, S.

    2013-04-01

    The regional climate model (RegCM3) from the Abdus Salam International Centre for Theoretical Physics has been used to simulate the Indian summer monsoon for three different monsoon seasons such as deficit (1987), excess (1988) and normal (1989). Sensitivity to various cumulus parameterization and closure schemes of RegCM3 driven by the National Centre for Medium Range Weather Forecasting global spectral model products has been tested. The model integration of the nested RegCM3 is conducted using 90 and 30-km horizontal resolutions for outer and inner domains, respectively. The India Meteorological Department gridded rainfall (1° × 1°) and National Centre for Environment Prediction (NCEP)-Department of Energy (DOE) reanalysis-2 of 2.5° × 2.5° horizontal resolution data has been used for verification. The RegCM3 forced by NCEP-DOE reanalysis-2 data simulates monsoon seasons of 1987 and 1988 reasonably well, but the monsoon season of 1989 is not represented well in the model simulations. The RegCM3 runs driven by the global model are able to bring out seasonal mean rainfall and circulations well with the use of the Grell and Anthes-Kuo cumulus scheme at 90-km resolution. While the rainfall intensity and distribution is brought out well with the Anthes-Kuo scheme, upper air circulation features are brought out better by the Grell scheme. The simulated rainfall distribution is better with RegCM3 using the MIT-Emanuel cumulus scheme for 30-km resolution. Several statistical analyses, such as correlation coefficient, root mean square error, equitable threat score, confirm that the performance of MIT-Emanuel scheme at 30-km resolution is better in simulating all-India summer monsoon rainfall. The RegCM3 simulated rainfall amount is more and closer to observations than that from the global model. The RegCM3 has corrected its driven GCM in terms of rainfall distribution and magnitude over some parts of India during extreme years. This study brings out several

  11. Seismicity of the Rwenzori Region, Western Uganda

    NASA Astrophysics Data System (ADS)

    Lindenfeld, M.; Rümpker, G.; Schumann, A.; Woelbern, I.

    2008-12-01

    The 5000m high Rwenzori Mountains are situated within the western branch of the East African Rift System (EARS), close to the equator at the border between Uganda and the Democratic Republic of Congo. They represent a basement block within the rift whose origin and relation to the development of the EARS are focus of the RiftLink project (www.riftlink.org). To investigate crustal and upper mantle structure in conjunction with seismic activity on a regional and local scale, a temporary seismic network was deployed over an area of roughly 80 x 140 km and operated from May 2006 to the end of September 2007. The analysis of the registered data revealed high microseismic activity in the region. On average more than 800 events per month were located during the registration period with local magnitudes ranging from -0.5 up to 5.1. Few earthquakes are located within the Rwenzori massive itself. Most of the events occur east and west of the mountains with a pronounced concentration of activity at a depth of about 15 km. Vertical sections across the northern parts of the Rwenzories show, that west of the mountains (towards the rift valley) the focal depths range from 10 to 20 km, whereas the hypocenters go as deep as 30 km on the eastern side. This is in good agreement with Moho depths that were derived from receiver functions and are close to 22 km west and 30 km east of the Rwenzories. There is one exception, however. Approximately 30 km east of the northern mountain ridge, we located a cluster of 7 events exhibiting an anomalous depth of about 60 km that occurred within 20 days in September 2006. These events are unique, up to now we located no other earthquakes at similar depths. P-wave polarities were used to determine fault plane solutions of events that were recorded by an adequate number of stations. Nearly all source mechanisms reveal normal faulting with strike directions more or less parallel to the rift axis and extension forces perpendicular to it. However

  12. Updated Long Term Fault Slip Rates and Seismic Hazard in the Central Alborz, Iran: New Constraints From InSAR and GPS

    NASA Astrophysics Data System (ADS)

    Weston, J. M.; Shirzaei, M.

    2015-12-01

    The Alborz mountain range, located south of the Caspian Sea, accommodates 30% of the 25 mm/yr convergence between Arabia and Eurasia. The resulting shortening and left lateral motion is distributed over several active fault zones within the Central Alborz. Despite earlier efforts using only GPS data, little is known about the long term rate of vertical deformation and aseismic slip. Several historical earthquakes have affected this region, some of the largest of these events occurred on the Mosha fault which is close to the capital city, Tehran, which has a population of over eight million. Thus, constraining the interseismic slip rates in this region is particularly important. In this study we complement existing horizontal velocities from a regional GPS network, with line of sight velocities from interferometric synthetic aperture radar (InSAR), to provide additional constraints on the vertical deformation and enhance the spatial coverage. Assuming a seismogenic depth of 30 km, based on microseismicity data, we solve for the geometry and long term slip rates on four major fault strands in this region. We obtain a long term slip rate of ~ 3 mm/yr for the Mosha and North Alborz faults, and ~ 10 mm/yr for the Khazar fault and Parchin faults. These rates and fault geometries are in agreement with earlier works, and fit the GPS data well. However, close to the fault traces there are large residuals in the InSAR data, suggesting that there is shallow creep (< 30 km). Therefore, we carry out a subsequent inversion using only the residual InSAR displacements to solve for the distribution of creep within the seismogenic zones on these faults. We find that the Mosha and North Alborz faults remain locked between 0 - 30 km depth, whilst the Parchin and Khazar faults are creeping. This new observation of fault creep has direct implications for the seismic hazard in the region. On the Mosha fault we estimate a slip deficit equivalent to a Mw 7.0 event. The combination of In

  13. Coseismic Deformation From the Haiti Earthquake of January 12, 2010, Detected by ALOS/PALSAR

    NASA Astrophysics Data System (ADS)

    Hashimoto, Manabu

    2010-05-01

    On January 12, 2010, a Mw7.0 earthquake hit southern Haiti and caused severe damages in and around Prot au Prince. This region has not suffered from strong earthquakes since 18th century, but rather high seismic risk is inferred from GPS observation (Mannaker et al., 2008). This earthquake is considered to have occurred on the Enriquillo fault. It is essential to reveal coseismic deformation from this earthquake and estimate fault parameters for the understanding of earthquake generation process and future seismic hazard evaluation. Unfortunately, no continous GPS data are available at present. Therefore we utilize synthetic aperture radar images. PALSAR (Phased Array type L-band SAR) is a L-band synthetic aperture radar onboard the Japanese satellite named Advanced Land Observation Satellite (hereafter ALOS). ALOS made an urgent observation of PALSAR on January 16 from the Path 138 with the off-nadir angle of 34.3 degree. Performing interferometry with the image acquired on October 11, 2007, we obtained an interferogram with CGIAR hole-filled SRTM DEM. The eastern edge of the obtained image is about 30km west of the epicenter. This area corresponds to an about 30km wide peninsula which extends westward from Port au Prince. However, we found at least three cycles of fringes (~40cm), which show increase of range toward the center of fringes, on the south side of the Enriquillo fault. We also recognized three cycles of fringes on the north side of the fault, but their gradient is much steeper than the south side. This observation implies eastward and/or subsidence of the southern block of the fault, which is consistent with left lateral strike-slip motion on a nearly vertical fault. Very preliminary analysis of fault model suggests that the western edge of the source fault is located about 30km west of the epicenter and slip may reach the surface and be as large as 2m, though there must be a trade off between slip and depth of fault. Observation of ALOS/PALSAR from

  14. Heat flow in eastern Egypt - The thermal signature of a continental breakup

    NASA Technical Reports Server (NTRS)

    Morgan, P.; Boulos, F. K.; Hennin, S. F.; El-Sherif, A. A.; El-Sayed, A. A.

    1985-01-01

    It is noted that the Red Sea is a modern example of continental fragmentation and incipient ocean formation. A consistent pattern of high heat flow in the Red Sea margins and coastal zone, including Precambrian terrane up to at least 30 km from the Red Sea, has emerged from the existing data. It is noted that this pattern has important implications for the mode and mechanism of Red Sea opening. High heat flow in the Red Sea shelf requires either a high extension of the crust in this zone (probably with major basic magmatic activity) or young oceanic crust beneath this zone. High heat flow in the coastal thermal anomaly zone may be caused by lateral conduction from the offshore lithosphere and/or from high mantle heat flow. It is suggested that new oceanic crust and highly extended continental crust would be essentially indistinguishable with the available data in the Red Sea margins, and are for many purposes essentially identical.

  15. Rapid N-S extension in the Mygdonian Graben (northern Greece) deduced from repeated geodetic surveys

    NASA Astrophysics Data System (ADS)

    Martinod, Joseph; Hatzfeld, Denis; Savvaidis, Paris; Katsambalos, Kostas

    In November 1994, a geodetic network situated on the Mygdonian graben, 30 km NE of Thessaloniki, Greece, was remeasured using the GPS technique. This network was established in 1979, in the epicentral area of the 1978 earthquake (Ms=6.5), and was measured using triangulation techniques seven times between 1979 and 1989. The comparison between 1979 and 1994 data shows that this part of the Mygdonian graben experienced about 8 cm of N-S horizontal extension. Most of the extension is concentrated in a narrow (one or two kilometers) E-W zone, located on the southern boundary of the graben. Furthermore, the analysis of repeated triangulation surveys suggests a rate of extension of 5.7±1.3 mm/y, that remained constant with time between 1979 and 1994. This extension could result from long-term postseismic relaxation processes, or from continous aseismic slip within the graben.

  16. The Iceland 1986 GPS geodetic survey - Tectonic goals and data processing results

    NASA Astrophysics Data System (ADS)

    Foulger, G. R.; Beutler, G.; Bilham, Roger; Einarsson, Pall; Fankhauser, S.; Gurtner, W.; Hugentobler, U.; Morgan, W. J.; Rothacher, M.; Thorbergsson, Gunnar

    1993-07-01

    The 1986 GPS survey of Iceland aimed to: (1) establish geodetic control in the South Iceland Seismic Zone (SISZ), to study destructive earthquakes there, (2) measure a country-wide network to form the basis of a new first order national network. 51 points were surveyed, with 20-30 km spacings within the SISZ and 100 km spacings elsewhere. An ambiguity-fixed ionosphere-free solution gave accuracies of 1-2 cm in the horizontal and 2-3 cm in the vertical for the SISZ network and an ambiguity-free ionosphere-free solution yielded accuracies of about 5 cm for the country-wide network. An ionosphere-free solution for the total survey with ambiguities fixed for the SISZ network only gave marginal additional improvements over the two separate solutions. GPS surveying has continued annually in Iceland with measurements in South Iceland in 1989 and 1992.

  17. Epoxy Composite Based on Kenaf Fibers for Tribological Applications Under Wet Contact Conditions

    NASA Astrophysics Data System (ADS)

    Yousif, B. F.; Chin, C. W.

    2012-10-01

    In the current work, kenaf fibers reinforced epoxy (KFRE) composite was developed. Adhesive wear and frictional characteristics of KFRE were investigated under wet contact conditions at different fiber orientations, considering different applied loads (50-200 N) and sliding distances (0-30 km). Scanning electron microscopy (SEM) was used to observe the damages on the worn surfaces. The results revealed that fiber orientation plays a main role in determining the wear and frictional performance of the composites. Kenaf fibers, in normal orientation (N-O), enhanced the wear performance of the composite by about 35%-57%. It appears that the damages on the surface of the composite (N-O) were less than the other orientations (P-O and AP-O). Compared to previous work, KFRE has good potential of replacing glass fibers in tribological applications.

  18. The Liege-balloon program. [balloon-borne instruments for high-spectral resolution observations of the sun

    NASA Technical Reports Server (NTRS)

    Zander, R.

    1974-01-01

    The Liege-balloon program is intended to make high-spectral resolution observations of the sun in the near- and intermediate infrared regions not accessible from the ground. A description of the equipment, followed by a summary of the data obtained till now is presented. Except for ozone whose maximum of concentration lies near 25 Km altitude, the residual mass distribution of the other mentioned molecules decreases with altitude. This is a self-explanatory argument for carrying out spectroscopic observations from platforms transcending the densest layers of the earth's atmosphere. The Liege balloon equipment is primarily intended for very high-resolution solar observations from about 27-30 Km altitude, in all spectral regions between 1.5 and 15.0 microns, not accessible from the ground.

  19. [Cytogenetic indices for somatic mutagenesis in mammals exposed to chronic low-dose irradiation].

    PubMed

    Kostenko, S A; Ermakova, O V; Sushko, S N; Fyedorova, E V; Dzhus, P P; Baschlykova, L A; Kurylenko, Yu F; Raskosha, O V; Savin, A O; Shaforost, A S

    2015-01-01

    We used cytogenetic analysis in the studies of the biological effects of a radiation factor of natural and artificial origin (under conditions ofthe 30-km exclusion zone ofthe Chernobyl experimental landfills in Ukraine, Belarus and Russia). The studies have been performed on various types of mammals: domestic animals--cows, pigs, horses and rodents--root voles, the Af mouse line, and yellow necked field mouse, bank voles. We found significant changes in the level of MN and chromosomal aberrations in the animals that were exposed to the conditions of chronic low-dose radiation for a long time (bothin the habitat and upon exposure in the Chernobyl zone) regardless of the type of animal and nature of contamination. PMID:25962274

  20. Real-time high-speed motion blur compensation system based on back-and-forth motion control of galvanometer mirror.

    PubMed

    Hayakawa, Tomohiko; Watanabe, Takanoshin; Ishikawa, Masatoshi

    2015-12-14

    We developed a novel real-time motion blur compensation system for the blur caused by high-speed one-dimensional motion between a camera and a target. The system consists of a galvanometer mirror and a high-speed color camera, without the need for any additional sensors. We controlled the galvanometer mirror with continuous back-and-forth oscillating motion synchronized to a high-speed camera. The angular speed of the mirror is given in real time within 10 ms based on the concept of background tracking and rapid raw Bayer block matching. Experiments demonstrated that our system captures motion-invariant images of objects moving at speeds up to 30 km/h. PMID:26698958

  1. Characteristics of Four Upward-Pointing Cosmic-Ray-like Events Observed with ANITA

    NASA Astrophysics Data System (ADS)

    Gorham, P. W.; Nam, J.; Romero-Wolf, A.; Hoover, S.; Allison, P.; Banerjee, O.; Beatty, J. J.; Belov, K.; Besson, D. Z.; Binns, W. R.; Bugaev, V.; Cao, P.; Chen, C.; Chen, P.; Clem, J. M.; Connolly, A.; Dailey, B.; Deaconu, C.; Cremonesi, L.; Dowkontt, P. F.; Duvernois, M. A.; Field, R. C.; Fox, B. D.; Goldstein, D.; Gordon, J.; Hast, C.; Hebert, C. L.; Hill, B.; Hughes, K.; Hupe, R.; Israel, M. H.; Javaid, A.; Kowalski, J.; Lam, J.; Learned, J. G.; Liewer, K. M.; Liu, T. C.; Link, J. T.; Lusczek, E.; Matsuno, S.; Mercurio, B. C.; Miki, C.; Miočinović, P.; Mottram, M.; Mulrey, K.; Naudet, C. J.; Ng, J.; Nichol, R. J.; Palladino, K.; Rauch, B. F.; Reil, K.; Roberts, J.; Rosen, M.; Rotter, B.; Russell, J.; Ruckman, L.; Saltzberg, D.; Seckel, D.; Schoorlemmer, H.; Stafford, S.; Stockham, J.; Stockham, M.; Strutt, B.; Tatem, K.; Varner, G. S.; Vieregg, A. G.; Walz, D.; Wissel, S. A.; Wu, F.; Anita Collaboration

    2016-08-01

    We report on four radio-detected cosmic-ray (CR) or CR-like events observed with the Antarctic Impulsive Transient Antenna (ANITA), a NASA-sponsored long-duration balloon payload. Two of the four were previously identified as stratospheric CR air showers during the ANITA-I flight. A third stratospheric CR was detected during the ANITA-II flight. Here, we report on characteristics of these three unusual CR events, which develop nearly horizontally, 20-30 km above the surface of Earth. In addition, we report on a fourth steeply upward-pointing ANITA-I CR-like radio event which has characteristics consistent with a primary that emerged from the surface of the ice. This suggests a possible τ -lepton decay as the origin of this event, but such an interpretation would require significant suppression of the standard model τ -neutrino cross section.

  2. Preliminary geologic terrain map of Mercury

    NASA Technical Reports Server (NTRS)

    Trask, N. J.; Guest, J. E.

    1975-01-01

    A geologic terrain map of Mercury has been constructed by use of the photogeologic methods employed for the moon and Mars. The oldest and most widespread unit, intercrater plains, forms nearly level to rolling surfaces on which are superposed numerous secondary impact craters. This unit may represent a very old surface that predates the last heavy bombardment of the inner planets. The effects of this bombardment are recorded in a second widespread unit, heavily cratered terrain, consisting of closely spaced craters and basins from 30 km to several hundred kilometers in diameter. Units formed by excavation of the 1300-km-diameter Caloris basin are widespread on one hemisphere of the planet. The development of the Caloris basin was followed relatively quickly by emplacement of widespread plains materials, most of which are probably volcanic.

  3. Detailed basal topography of the floating portion of Pine Island Glacier, West Antarctica

    NASA Astrophysics Data System (ADS)

    Dutrieux, Pierre; Jenkins, Adrian; Stewart, Craig; Corr, Hugh

    2013-04-01

    In January 2009 the underside of Pine Island glacier's floating ice shelf, in West Antarctica, was imaged along three 30 km tracks using an upward-looking multi-beam echo-sounder mounted on an autonomous underwater vehicle. At 4-m resolution with a 300-m wide swath, these observations reveal with unprecedented detail the presence of channels oriented along and across the direction of ice flow. Many of these channels are characterized by basal crevasses above their apex and successive 200-500 m wide, 10-20m high terraces on their flanks. A near coincident, high resolution airborne radar survey confirm the widespread nature of these features. The oceanographic and glaciological conditions of Pine Island glacier are discussed to shed light on the processes leading to their formation and maintenance. For comparison, observations of terraces in a different setting, but in a similar oceanographic context in Greenland are also presented.

  4. A comparison of operational Lagrangian particle and adaptive puff models for plume dispersion forecasting

    NASA Astrophysics Data System (ADS)

    Souto, M. J.; Souto, J. A.; Pérez-Muñuzuri, V.; Casares, J. J.; Bermúdez, J. L.

    Transport and dispersion of pollutants in the lower atmosphere are predicted by using both a Lagrangian particle model (LPM) and an adaptive puff model (APM2) coupled to the same mesoscale meteorological prediction model PMETEO. LPM and APM2 apply the same numerical solutions for plume rise; but, for advection and plume growth, LPM uses a stochastic surrogate to the pollutant conservation equation, and APM2 applies interpolated winds and standard deviations from the meteorological model, using a step-wise Gaussian approach. The results of both models in forecasting the SO 2 ground level concentration (glc) around the 1400 MWe coal-fired As Pontes Power Plant are compared under unstable conditions. In addition, meteorological and SO 2 glc numerical results are compared to field measurements provided by 17 fully automated SO 2 glc remote stations, nine meteorological towers and one Remtech PA-3 SODAR, from a meteorological and air quality monitoring network located 30 km around the power plant.

  5. A New Wideband, Fully Steerable, Decametric Array at Clark Lake

    NASA Technical Reports Server (NTRS)

    Erickson, W. C.; Fisher, J. R.

    1974-01-01

    A fully steerable, decametric array for radio astronomy is under construction at the Clark Lake Radio Observatory near Borrego Springs, California. This array will be a T of 720 conical spiral antennas (teepee-shaped antennas, hence the array is called the TPT), 3.0 km by 1.8 km capable of operating between 15 and 125 MHz. Both its operating frequency and beam position will be adjustable in less than one millisecond, and the TPT will provide a 49-element picture around the central beam position for extended source observations. Considerable experience was gained in the operation of completed portions of the array, and successful operation of the final array is assured. The results are described of the tests which were conducted with the conical spirals, and the planned electronics and data processing systems are described.

  6. The fractured Moon: Production and saturation of porosity in the lunar highlands from impact cratering

    NASA Astrophysics Data System (ADS)

    Soderblom, Jason M.; Evans, Alexander J.; Johnson, Brandon C.; Melosh, H. Jay; Miljković, Katarina; Phillips, Roger J.; Andrews-Hanna, Jeffrey C.; Bierson, Carver J.; Head, James W.; Milbury, Colleen; Neumann, Gregory A.; Nimmo, Francis; Smith, David E.; Solomon, Sean C.; Sori, Michael M.; Wieczorek, Mark A.; Zuber, Maria T.

    2015-09-01

    We have analyzed the Bouguer anomaly (BA) of ~1200 complex craters in the lunar highlands from Gravity Recovery and Interior Laboratory observations. The BA of these craters is generally negative, though positive BA values are observed, particularly for smaller craters. Crater BA values scale inversely with crater diameter, quantifying how larger impacts produce more extensive fracturing and dilatant bulking. The Bouguer anomaly of craters larger than 93-19+47 km in diameter is independent of crater size, indicating that there is a limiting depth to impact-generated porosity, presumably from pore collapse associated with either overburden pressure or viscous flow. Impact-generated porosity of the bulk lunar crust is likely in a state of equilibrium for craters smaller than ~30 km in diameter, consistent with an ~8 km thick lunar megaregolith, whereas the gravity signature of larger craters is still preserved and provides new insight into the cratering record of even the oldest lunar surfaces.

  7. Deceleration of the solar wind in the Earth foreshock region: ISEE 2 and IMP 8 observations

    NASA Technical Reports Server (NTRS)

    Bonifazi, C.; Moreno, G.; Lazarus, A. J.; Sullivan, J. D.

    1980-01-01

    The deceleration of the solar wind in the region of the interplanetary space filled by ions backstreaming from the Earth bow shock was studied using a two spacecraft technique. This deceleration, which is correlated with the "diffuse" but not with the "reflected" ion population, depends on the solar wind bulk velocity: at low velocities (below 300 km/sec) the velocity decrease is about 5 km/sec, while at higher velocities (above 400 km/sec) the decrease may be as large as 30 km/sec. Along with this deceleration, the solar wind undergoes a deflection of about 1 deg away from the direction of the Earth bow shock. The energy balance shows that the kinetic energy loss far exceeds the thermal energy which is possibly gained by the solar wind, therefore, at least part of this energy must go into waves and/or into the backstreaming ions.

  8. FGGE/SMMR-30 tape specification and shipping letter description

    NASA Technical Reports Server (NTRS)

    Han, D.; Lo, H.

    1983-01-01

    The Nimbus-7 FGGE/SMMR-30 tape which contains sea ice concentration data in 30 km resolution which are extracted and reformatted from Nimbus-7 SMMR PARM-30 tapes in accordance with the FGGE level II International Exchange Format Specification is outlined. There are three types of files on a FGGE/SMMR-30 tape. The first file on the tape is a test file. The second file on the tape is a tape header file. The remaining one or more files are data files. All files are terminated with a single end of file (EOP) tape mark. The last file is terminated with two EOF tape marks. All files are made up of one or more physical records. Each physical record contains 2960 bytes. Each data file contains all available values for a 6 hour synoptic time period.

  9. Thrust-type focal mechanisms of tectonic tremors in Taiwan: Evidence of subduction

    NASA Astrophysics Data System (ADS)

    Ide, Satoshi; Yabe, Suguru; Tai, Hsin-Ju; Chen, Kate Huihsuan

    2015-05-01

    Unlike tectonic tremors in subduction zones and along transform faults, the hosting structure for tremors in Taiwan remains debated. Tectonic tremors in Taiwan have been discovered at ~30 km depth beneath the southern Central Range, which is a young and active collisional mountain belt. Here we provide the first evidence for the focal mechanism of tremor using moment tensor inversion in the very low frequency band, employing broadband seismograms stacked relative to the hypocentral time of tremor. The best solution corresponds to low-angle thrust faulting, suggesting the subduction of the Eurasian plate. This mechanism is consistent with strong tidal modulation of tremor activity but differs from the normal-type faulting that dominates regional shallow earthquakes. This result suggests vertical variations in the tectonic stress regime. Thrust faulting may be facilitated by a decrease in normal stress due to the buoyant roots of the mountain belt and local high fluid pressure.

  10. Fukushima Daiichi Accident and Its Radiological Impact on the Environment

    NASA Astrophysics Data System (ADS)

    Bevelacqua, J. J.

    2012-09-01

    The Fukushima Daiichi nuclear accident is a topic of current media and public interest. It provides a means to motivate students to understand the fission process and the barriers that have been designed to prevent the release of fission products to the environment following a major nuclear power reactor accident. The Fukushima Daiichi accident further encourages a discussion of the effect of fission products upon the environment, including the resulting contamination of air, water, soil, animals, fish, milk, and crops. Accident-generated radiation levels that caused the evacuation of people 20-30 km from the facility further serve to foster student interest and desire to understand the science associated with the Fukushima Daiichi accident.

  11. IUE data reduction - The parameterization of the motion of the IUE reseau grids and spectral formats as a function of time and temperature

    NASA Technical Reports Server (NTRS)

    Thompson, R. W.; Turnrose, B. E.; Bohlin, R. C.

    1982-01-01

    Improvements are made on IUE data reduction using corrected reseau positions and dispersion constants for temperature variations and secular effects. Models describing the motion of the high dispersion spectral format as a function of THDA alone reduce the scatter in the predicted position of a given wavelength, and scatter is further reduced when a linear dependence on time is also allowed. A correction technique is presented for early data which reduces errors in wavelength assignments from over 30 km/s to less than 3 km/s in high dispersion. The reseau temperature correction helps locate the minimum background signal, centered between the echelle orders. The residual uncertainty of 2 km/s for SWP and 2.7 km/s for LWR makes the wavelength accuracy of time and temperature corrected IUE spectra comparable to that of temperature corrected data from the Copernicus satellite.

  12. A comparative Rb-Sr, Sm-Nd, and K-Ar study of shocked norite 78236 - Evidence of slow cooling in the lunar crust

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Bogard, D. D.; Wooden, J. L.; Bansal, B. M.; Wiesmann, H.; Shih, C.-Y.; Reimold, W. U.

    1982-01-01

    The sample 78236 was chipped from the top of a norite boulder at Station 8 by the Apollo 17 landing team. Jackson et al. (1975) concluded that this rock formed at a depth of 8-30 km in the lunar crust and suggested that it was excavated by a large basin-forming impact event. A petrographic description of the boulder is provided, and isotopic analyses are discussed. Attention is given to a chronology for 78236 which seems to be most consistent with radiometric and other evidence. It is proposed that cumulate norite 78236 formed deep in the lunar crust approximately 4.4 AE ago. The rock cooled slowly in the crust until it was excavated by a major basin-forming event. Excavation may have occurred about 4.2 AE ago, but the time of this event is not well constrained.

  13. Crustal Heat Production and the Thermal Evolution of Mars. Revision

    NASA Technical Reports Server (NTRS)

    McLennan, Scott M.

    2001-01-01

    The chemical compositions of soils and rocks from the Pathfinder site and Phobos-2 orbital gamma-ray spectroscopy indicate that the Martian crust has a bulk composition equivalent to large-ion lithophile (LIL) and heat-producing element (HPE) enriched basalt, with a potassium content of about 0.5%. A variety of radiogenic isotopic data also suggest that separation of LIL-enriched crustal and depleted mantle reservoirs took place very early in Martian history (greater than 4.0 Ga). Accordingly, if the enriched Martian crust is greater than 30km thick it is likely that a large fraction (up to at least 50%) of the heat-producing elements in Mars was transferred into the crust very early in the planet's history. This would greatly diminish the possibility of early widespread melting of the Martian mantle.

  14. The South Pole Imaging Fabry Perot Interferometer (SPIFI)

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Bradford, C. M.; Swain, M. R.; Jackson, J. M.; Bolato, A. D.; Davidson, J. A.; Savage, M.

    1996-01-01

    The design and construction of the South Pole imaging Fabry-Perot interferometer (SPIFI) is reported. The SPIFI is a direct detection imaging spectrometer for use in the far infrared and submillimeter bands accessible to the 1.7 m telescope at the South Pole, and in the submillimeter bands accessible to the 15 m James Clerk Maxwell Telescope (JCMT), HI. It employs a 5 x 5 silicon bolometer array and three cryogenic Fabry Perot interferometers in series in order to achieve velocity resolutions of between 300 km/s and 30 km/s over the entire field of view with a resolution of up to 1 km/s at the center pixel. The scientific justification for the instrument is discussed, considering the spectral lines available to SPIFI. The optical path, the cryogenic Fabry-Perot, the adiabatic demagnetization refrigerator and the detector array are described. The instrument's sensitivity is presented and compared with coherent systems.

  15. The Coupling of the Numerical Heat Transfer Model of the Pauzhetka Hydrothermal System (Kamchatka, USSR) with Hydroisotopic Data

    SciTech Connect

    Kiryukhin, A.V.; Sugrobov, V.M.

    1986-01-21

    The application of the two-dimensional numerical heat-transfer model to the Pauzhetka hydrothermal system allowed us to establish that: (1) a shallow magma body with the anomalous temperature of 700-1000 C and with a volume of 20-30 km{sup 3} may be a heat source for the formation of the Pauzhetka hydrothermal system. (2) The water feeding source of the Pauzhetka hydrothermal system may be meteoric waters which are infiltrated at an average rate of 5-10 kg/s {center_dot} km{sup 2}. The coupling of the numerical heat-transfer model with hydroisotopic data (D,T,{sup 18}O) obtained from the results of testing of exploitation wells, rivers and springs is the basis to understand more clearly the position of recharge areas and the structure of water flows in the hydrothermal system.

  16. Catastrophic collapse of the west Florida carbonate platform margin

    SciTech Connect

    Mullins, H.T.; Gardulski, A.F.; Hine, A.C.

    1986-02-01

    A large truncation surface has been discovered on seismic reflection profiles along the distally steepened ramp of the west Florida carbonate platform margin. This structure, interpreted as a submarine slide scar, is at least 120 km across and up to 30 km wide; the slide has removed as much as 300-350 m of late Paleogene and early Neogene strata. Collapse occurred in the middle Miocene within an episode of seaward progradation during a relative sea-level highstand. Postcollapse depositional sequences thicken abruptly across the structure; this suggests catastrophic slope failure. Gravitational instability, created by high rates of sediment accumulation, is believed to have been the triggering mechanism. Such large-scale platform-margin collapse is likely to generate megabreccia debris flows as well as aid in the landward retreat of precipitous, high-relief carbonate escarpments.

  17. Burials from Wadi Mudayfa'at and Wadi Abu Khasharif, Southern Jordan - Results of a Survey and Salvage Excavations

    NASA Astrophysics Data System (ADS)

    Salameen, Zeyad al; Falahat, Hani

    This paper presents the preliminary results of a survey and excavation conducted in 2006 on small cemeteries at Wadi Mudayfa'at and Wadi Abu Khasharif, which are located c. 30 km southeast of the village of al-Hussayniah on the Desert Highway in southern Jordan. In total five graves were excavated. Preservation was excellent including human and other organic materials (hair, leather, textiles). Preliminary scientific dating points to the period between the second and fourth centuries AD. The research questions discussed are: - the date, the relationship between the cemeteries and surrounding sites, the significance of this area, the identity of the groups buried, the burial techniques and practices adopted and what influenced them and the funerary gifts included with the dead.

  18. Lens-effect in Santa Monica?

    NASA Astrophysics Data System (ADS)

    Alex, Carmen M.; Olsen, Kim B.

    We used finite-difference simulations of 10-Hz P-SV and SH waves to estimate the contribution from the deep basin structure to the large ground motion amplification in Santa Monica, California, observed for seismic waves incident from the north. Our simulations of a 17-km deep Northridge aftershock with epicenter 30 km north of Santa Monica show that focusing at the lens-shaped boundary of the sediments can only account for less than half the amplification observed in the area that was heavily damaged during the 1994 M 6.7 Northridge earthquake. The focusing in the simulations caused amplification of up to 1.6 times in a zone 0.65-2.4 km south of the Santa Monica fault and de-amplification at sites just south of the fault where some of the largest amplification is observed in the data.

  19. Martian atmospheric radiation budget

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1994-01-01

    A computer model is used to study the radiative transfer of the martian winter-polar atmosphere. Solar heating at winter-polar latitudes is provided predominately by dust. For normal, low-dust conditions, CO2 provides almost as much heating as dust. Most heating by CO2 in the winter polar atmosphere is provided by the 2.7 micron band between 10 km and 30 km altitude, and by the 2.0 micron band below 10 km. The weak 1.3 micron band provides some significant heating near the surface. The minor CO2 bands at 1.4, 1.6, 4.8 and 5.2 micron are all optically thin, and produce negligible heating. O3 provides less than 10 percent of the total heating. Atmospheric cooling is predominantly thermal emission by dust, although CO2 15 micron band emission is important above 20 km altitude.

  20. Differential impact cratering of Saturn's satellites by heliocentric impactors

    NASA Astrophysics Data System (ADS)

    Hirata, Naoyuki

    2016-02-01

    Saturnian satellites are thought to have been struck by two different types of impactors: those with heliocentric origins and those with planetocentric origins. Many of the impacts are suggested to come from planetocentric debris, while many crater count studies assume an ecliptic comet origin when determining the ages of the surfaces. To assess the contribution of planetocentric impactors, this study examines the global distribution and apex-antapex asymmetry of impact craters on Rhea and Iapetus. The results demonstrate that the craters of Rhea (more than 20 km in diameter) and Iapetus (more than 30 km in diameter) show an apex-antapex asymmetry. This suggests that most of the large craters are formed from heliocentric impacts. In contrast, the craters less than 20 km in diameter seem to show no asymmetry. Possible explanations for this are either planetocentric impactor origins or saturation with impact craters.

  1. Prospects of passive radio detection of a subsurface ocean on Europa with a lander

    NASA Astrophysics Data System (ADS)

    Romero-Wolf, Andrew; Schroeder, Dustin M.; Ries, Paul; Bills, Bruce G.; Naudet, Charles; Scott, Bryan R.; Treuhaft, Robert; Vance, Steve

    2016-09-01

    We estimate the sensitivity of a lander-based instrument for the passive radio detection of a subsurface ocean beneath the ice shell of Europa, expected to be between 3 km and 30 km thick, using Jupiter's decametric radiation. A passive technique was previously studied for an orbiter. Using passive detection in a lander platform provides a point measurement with significant improvements due to largely reduced losses from surface roughness effects, longer integration times, and diminished dispersion due to ionospheric effects allowing operation at lower frequencies and a wider band. A passive sounder on-board a lander provides a low resource instrument sensitive to subsurface ocean at Europa up to depths of 6.9 km for high loss ice (16 dB/km two-way attenuation rate) and 69 km for pure ice (1.6 dB/km).

  2. Discharge dynamics of pin-to-plate dielectric barrier discharge at atmospheric pressure

    SciTech Connect

    Sun Liqun; Huang, Xiaojiang; Zhang Jie; Zhang Jing; Shi, J. J.

    2010-11-15

    The discharge dynamics of pin-to-plate dielectric barrier discharge was studied in atmospheric helium at 20 kHz. The discharge was predominately ignited in positive half cycle of applied voltage with sinusoidal waveform. The temporal evolution of the discharge was investigated vertically along the discharge gap and radically on the dielectric surface by time resolved imaging. It is found that a discharge column with a diameter of 2 mm was ignited above the pin electrode and expanded toward a plate electrode. On the dielectric surface with space charge accumulation, plasma disk in terms of plasma ring was formed with radius up to 25 mm. The expansion velocity of plasma ring can reach a hypersonic speed of 3.0 km/s. The ionization wave due to electron diffusion is considered to be the mechanism for plasma ring formation and dynamics.

  3. Preliminary Analysis of AVIRIS Data for Tectonostratigraphic Assessment of Northern Guerrero State, Southern Mexico

    NASA Technical Reports Server (NTRS)

    Lang, Harold R.; Cabral-Cano, Enrique

    1996-01-01

    The tectonostratigraphic evolution of the southern margin of the North America Plate in Mexico is still in debate. Recent explanations assert Laramide age (Campanian-Eocene) accretion of far-travelled oceanic terranes. In 1989, we began an effort to bring new data to this debate through field mapping, incorporating Landsat Thematic Mapper and digital elevation data, along a 30 km by 250 km, east-west geologic transect of northern Guerrero State. Covering the region from Huetamo, Michoacan, to Papalutla, Guerrero (between latitude 18-19 deg N and longitude 101-99 deg W), our mapping results show that no stratigraphic incompatibilities suggesting terrane accretion exist in the region. In November 1994, AVIRIS data were acquired along the geologic transect in order to refine our stratigraphic assessment. One objective of this hyperspectral survey was to improve mapping of limestone, dolostone and gypsum-bearing facies of the Morelos Formation which record rudist carbonate platform environments during mid-Cretaceous time.

  4. Properties of haze in the atmosphere of Triton

    NASA Technical Reports Server (NTRS)

    Krasnopolsky, V. A.; Sandel, B. R.; Herbert, F.

    1992-01-01

    Voyager UV spectrometer measurements of CH4 and haze of the Triton atmosphere combined with the haze brightness profile determined by the narrow angle camera are used to infer a haze optical thickness of 0.024 at 1500 A and 0.0078 in the spectral range of the narrow angle camera centered at 4700A, rho/gamma = 0.36 +/- 0.1 g/cu cm (gamma is the quantum yield of condensate), and values of r(c) varying from 0.1 +/- 0.02 micron at 30 km to 0.15 +/- 0.03 micron near the surface. Other auxiliary properties of the haze are also determined. The value found for rho/gamma corresponds to a packing coefficient of 0.6 gamma if C2H4 is the main condensible species.

  5. Rupture process of the 2016 Kumamoto earthquake in relation to the thermal structure around Aso volcano

    NASA Astrophysics Data System (ADS)

    Yagi, Yuji; Okuwaki, Ryo; Enescu, Bogdan; Kasahara, Amato; Miyakawa, Ayumu; Otsubo, Makoto

    2016-07-01

    We constructed the rupture process model for the 2016 Kumamoto, Japan, earthquake from broadband teleseismic body waveforms (P-waves) by using a novel waveform inversion method that takes into account the uncertainty of Green's function. The estimated source parameters are: seismic moment = 5.1 × 1019 Nm (Mw = 7.1), fault length = 40 km, and fault width = 15 km. The mainshock rupture mainly propagated northeastward from the epicenter, for about 30 km, along an active strike-slip fault. The rupture propagation of the mainshock decelerated and terminated near the southwest side of the Aso volcano; the aftershock activity was low around the northeastern edge of the major slip area. Our results suggest that the rupture process of the mainshock and the distribution of aftershocks were influenced by the high-temperature area around the magma chamber of Mt. Aso.

  6. Neotropical Monogenoidea. 54. Proposal of Aetheolabes n. g. (Dactylogyrinea: Diplectanidae), with the description of A. goeldiensis n. sp. from the gills of 'pescada' Plagioscion sp. (Teleostei: Sciaenidae) in Brazil.

    PubMed

    Boeger, Walter A; Kritsky, Delane C

    2009-10-01

    Aetheolabes goeldiensis n. g., n. sp. (Diplectanidae) is described from the gills of 'pescada' Plagioscion sp. (Sciaenidae) collected from the Baía de Marajó, about 30 km north of Belém, Pará, Brazil. The monotypic Aetheolabes n. g. is characterised, in part, by its type-species having the haptor and haptoral sclerites modified as a clasp for attachment to the gill tissue of its host, the copulatory complex situated far posterior to the intestinal bifurcation near the mid-length of the trunk, the vaginal pore apparently within the genital atrium, the tegument lacking scales, anchors atypical for diplectanids, and by lacking peduncular spines and squamodiscs. A. goeldiensis n. sp. closely resembles Diplectanum umbrinum Tripathi, 1957 from India and China by the haptoral sclerites forming a clasp, but differs from it primarily by the orientation of the reproductive organs and absence of squamodiscs. PMID:19731097

  7. A photometric and spectrographic study of BP Pegasi

    SciTech Connect

    Kim, C.; Mcnamara, D.H.; Joner, M.D. Brigham Young Univ., Provo, UT )

    1989-11-01

    Photometric (uvby beta) and spectrographic observations of the dwarf Cepheid BP Peg are discussed. The observations are used to derive a reddening value of E(b-y) = 0.067 m. An effective temperature of 7470 K, a mean surface gravity, log g = 3.85, and a Fe/H abundance ratio of - 0.08 are obtained. Pulsation theory and stellar model sequences yield M(bol) = 1.4 m, mass = 1.85 solar masses, and age = 1.3 X 10 to the 9th yrs. Also, the radial-velocity data show a mean radial velocity of - 30 km/s and a total velocity range of 36 km/s. 14 refs.

  8. 2D velocity and temperature measurements in high speed flows based on spectrally resolved Rayleigh scattering

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.

    1992-01-01

    The use of molecular Rayleigh scattering for measurements of gas velocity and temperature is evaluated. Molecular scattering avoids problems associated with the seeding required by conventional laser anemometry and particle image velocimetry. The technique considered herein is based on the measurement of the spectrum of the scattered light. Planar imaging of Rayleigh scattering using a laser light sheet is evaluated for conditions at 30 km altitude (typical hypersonic flow conditions). The Cramer-Rao lower bounds for velocity and temperature measurement uncertainties are calculated for an ideal optical spectrum analyzer and for a planar mirror Fabry-Perot interferometer used in a static, imaging mode. With this technique, a single image of the Rayleigh scattered light from clean flows can be analyzed to obtain temperature and one component of velocity. Experimental results are presented for planar velocity measurements in a Mach 1.3 air jet.

  9. Effective elastic thickness of the Arabian plate: Weak shield versus strong platform

    NASA Astrophysics Data System (ADS)

    Chen, Bo; Kaban, Mikhail K.; El Khrepy, Sami; Al-Arifi, Nassir

    2015-05-01

    The fan wavelet method has been employed to calculate high-resolution maps of variations of the effective elastic thickness (EET) for the Arabian plate and surroundings. As the initial data, we use high-resolution gravity field, topography, and recent models of sedimentary basins. The western part of the plate is generally characterized by low to midvalues of EET (10-30 km) while the eastern one by high values (50 km and more in the core). This finding confirms that the pronounced asymmetry of the plate is rather associated with fundamental structural differences of the lithosphere than with a forced tilt of the plate due to the rifting in the west-southwest and subduction in the northeast. Therefore, the high topography in the western part of the plate is likely supported by relatively hot mantle that is also responsible for the decrease of EET. These results are generally in agreement with recent seismic tomography models.

  10. Intra-Seasonal Monthly Oscillations in Stratospheric NCEP Data and Model Results

    NASA Technical Reports Server (NTRS)

    Mayr, H. G.; Mengel, J. G.; Huang, F. T.; Nash, E. R.

    2009-01-01

    Intra-seasonal oscillations (ISO) are observed in the zonal-mean of mesospheric wind and temperature measurements-and the numerical spectral model (NSM) generates such oscillations. Relatively large temperature ISO are evident also in stratospheric CPC (NCEP) data at high latitudes, where the NSM produces amplitudes around 3 K at 30 km. Analyzing the NCEP data for the years 1996-2006, we find in Fourier spectra signatures of oscillations with periods between 1.7 and 3 months. With statistical confidence levels exceeding 70%, the spectral features are induced by nonlinear interactions involving the annual and semi-annual variations. The synthesized data show for the 10-year average that the temperature ISO peak in winter, having amplitudes close to 4 K. The synthesized complete spectrum for periods around 2 months produces oscillations, varying from year to year, which can reach peak amplitudes of 15 and 5 K respectively at northern and southern polar latitudes.

  11. High-resolution simulation of a nocturnal narrow convective line off the southeastern coast of Taiwan in the Mei-yu season

    NASA Astrophysics Data System (ADS)

    Wang, Chung-Chieh; Huang, Wei-Ming

    2009-03-01

    This study performed high-resolution numerical simulation on a convective line that occurred roughly 10-30 km offshore of southeastern Taiwan overnight of 14-15 May 1998. Three experiments at successively higher resolution (10, 2, and 0.5 km) but smaller domain were carried out, and the narrow line is eventually reproduced. It is found that shallow (offshore) return flow along the coast appeared since daytime due to topographic blocking on the weak prevailing (onshore) south-southeasterly wind, producing convergence at their interface near shore. During the night, mountain breeze further strengthened the offshore flow and convergence, and the line initiated. Once developed, downdrafts and outflow boundaries from old clouds triggered new clouds, and this was more active along the (eastern) boundaries against the undisturbed environmental flow. Thus, repeated new cloud formation took place throughout the night and into the next morning.

  12. Population, reproduction and foraging of pigeon guillemots at Naked Island, Alaska, before and after the Exxon Valdez oil spill. Bird study number 9. Exxon Valdez oil spill state/federal natural resource damage assessment final report

    SciTech Connect

    Oakley, K.L.; Kuletz, K.J.

    1994-01-01

    Following the 1989 Exxon Valdez oil spill in Prince William Sound (PWS), Alaska, we studied pigeon guillemots (Cepphus columba) breeding just 30 km from the grounding site. The post-spill population was 43% less than the pre-spill population, but we could not attribute the entire decline to the spill because a decline in the PWS guillemot population may have predated the spill. However, relative declines in the population were greater along oiled shorelines, suggesting that the spill was responsible for some of the decline. The most likely explanation for the few effects observed is that oil was present on the surface waters of the study area for a relatively short period before the guillemots returned to begin their annual reproductive activities.

  13. The analysis of temporal variations in regional models of the Sargasso Sea from GEOS-3 altimetry

    NASA Technical Reports Server (NTRS)

    Mather, R. S.; Coleman, R.; Hirsch, B.

    1978-01-01

    The dense coverage of short pulse mode GEOS-3 altimeter data in the western North Atlantic provides a basis for studying time variations in the sea surface heights in the Sargasso Sea. Two techniques are utilized: the method of regional models, and the analysis of overlapping passes. An 88 percent correlation is obtained between the location of cyclonic eddies obtained from infrared imagery and sea surface height minima in the altimeter models. This figure drops to 59 percent in the case of correlations with maxima and minima of surface temperature fields. The analysis of overlapping passes provides a better picture of instantaneous sea state through wavelengths greater than 30 km. The variability of the Sargasso Sea through wavelengths between 150 km and 5000 km is estimated at + or - 28 cm. This value is in reasonable agreement with oceanographic estimates and is compatible with the eddy kinetic energy of a wind driven circulation.

  14. Temporal variations in regional models of the Sargasso Sea from GEOS-3 altimetry

    NASA Technical Reports Server (NTRS)

    Mather, R. S.; Coleman, R.; Hirsch, B.

    1980-01-01

    The paper considers temporal variations in regional models of the Sargasso sea from GEOS-3 telemetry. The methods of regional models and the analysis of overlapping passes are utilized, and short-wave maxima and minima in the regional surface models are examined for correlations with surface and remote sensed infrared temperature data supplemented with subsurface expendable bathythermograph data (XBT). The analysis of overlapping passes provide a better picture of instanteneous sea surface height (SSH) variability through wavelengths greater than 30 km. Correlation studies with cyclonic and anticyclonic ocean eddies from infrared imagery and XBT data indicate satisfactory agreement with equivalent SSH features 98% of the time if the time varying factors are allowed for.

  15. Planetary atmospheres minor species sensor balloon flight test to near space

    NASA Astrophysics Data System (ADS)

    Peale, Robert E.; Fredricksen, Christopher J.; Muraviev, Andrei V.; Maukonen, Douglas; Quddusi, Hajrah M.; Calhoun, Seth; Colwell, Joshua E.; Lachenmeier, Timothy A.; Dewey, Russell G.; Stern, Alan; Padilla, Sebastian; Bode, Rolfe

    2015-05-01

    The Planetary Atmospheres Minor Species Sensor (PAMSS) is an intracavity laser absorption spectrometer that uses a mid-infrared quantum cascade laser in an open external cavity for sensing ultra-trace gases with parts-per-billion sensitivity. PAMSS was flown on a balloon by Near Space Corporation from Madras OR to 30 km on 17 July 2014. Based on lessons learned, it was modified and was flown a second time to 32 km by World View Enterprises from Pinal AirPark AZ on 8 March 2015. Successes included continuous operation and survival of software, electronics, optics, and optical alignment during extreme conditions and a rough landing. Operation of PAMSS in the relevant environment of near space has significantly elevated its Technical Readiness Level for trace-gas sensing with potential for planetary and atmospheric science in harsh environments.

  16. ACE infrared spectral atlases of the Earth's atmosphere

    NASA Astrophysics Data System (ADS)

    Hughes, Ryan; Bernath, Peter; Boone, Chris

    2014-11-01

    Five infrared atmospheric atlases are presented using solar occultation spectra from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) in low earth orbit. The spectral atlases were created for Arctic summer, Arctic winter, mid-latitude summer, mid-latitude winter and the tropics. Each covers the spectral range from 700 to 4400 cm-1 and consists of 31 spectra that span an altitude range of 6-126 km in 4-km altitude intervals. To improve the signal-to-noise ratio, each spectrum in the atlas is an average of at least several hundred individual ACE-FTS limb transmission spectra. Representative plots in pdf format at 10 km (troposphere), 30 km (stratosphere), 70 km (mesosphere), and 110 km (lower thermosphere) are also available.

  17. Reinterpretation of the stratigraphy and structure of the Rancho Las Norias area, central Sonora, Mexico

    USGS Publications Warehouse

    Page, W.R.; Harris, A.G.; Poole, F.G.; Repetski, J.E.

    2003-01-01

    New geologic mapping and fossil data in the vicinity of Rancho Las Norias, 30 km east of Hermosillo, Sonora, Mexico, show that rocks previously mapped as Precambrian instead are Paleozoic. Previous geologic maps of the Rancho Las Norias area show northeast-directed, southwest-dipping reverse or thrust faults deforming both Precambrian and Paleozoic rocks. The revised stratigraphy requires reinterpretation of some of these faults as high-angle normal or oblique-slip faults and the elimination of other faults. We agree with earlier geologic map interpretations that compressional structures have affected the Paleozoic rocks in the area, but our mapping suggests that the direction of compression is from southeast to northwest. Published by Elsevier Ltd.

  18. A global view of gravity waves in the Martian atmosphere inferred from a high-resolution general circulation model

    NASA Astrophysics Data System (ADS)

    Kuroda, Takeshi; Medvedev, Alexander S.; Yiǧit, Erdal; Hartogh, Paul

    2015-11-01

    Global characteristics of the small-scale gravity wave (GW) field in the Martian atmosphere obtained from a high-resolution general circulation model (GCM) are presented for the first time. The simulated GW-induced temperature variances are in a good agreement with available radio occultation data in the lower atmosphere between 10 and 30 km. The model reveals a latitudinal asymmetry with stronger wave generation in the winter hemisphere and two distinctive sources of GWs: mountainous regions and the meandering winter polar jet. Orographic GWs are filtered, while propagating upward, and the mesosphere is primarily dominated by harmonics with faster horizontal phase velocities. Wave fluxes are directed mainly against the local wind. GW dissipation in the upper mesosphere generates body forces of tens of m s-1 per Martian solar day (sol-1), which tend to close the simulated jets. The results represent a realistic surrogate for missing observations, which can be used for constraining GW parameterizations and validating GCM simulations.

  19. Measurements of the ionization coefficient of simulated iron micrometeoroids

    NASA Astrophysics Data System (ADS)

    Thomas, Evan; Horányi, Mihály; Janches, Diego; Munsat, Tobin; Simolka, Jonas; Sternovsky, Zoltan

    2016-04-01

    The interpretation of meteor radar observations has remained an open problem for decades. One of the most critical parameters to establish the size of an incoming meteoroid from radar echoes is the ionization coefficient, β, which still remains poorly known. Here we report on new experiments to simulate micrometeoroid ablation in laboratory conditions to measure β for iron particles impacting N2, air, CO2, and He gases. This new data set is compared to previous laboratory data where we find agreement except for He and air impacts > 30 km/s. We calibrate the Jones model of β(v) and provide fit parameters to these gases and find agreement with all gases except CO2 and high-speed air impacts where we observe βair > 1 for velocities > 70 km/s. These data therefore demonstrate potential problems with using the Jones model for CO2 atmospheres as well as for high-speed meteors on Earth.

  20. Variations in propagation delay times for line ten (TV) based time transfers

    NASA Technical Reports Server (NTRS)

    Chiu, M. C.; Shaw, B. W.

    1982-01-01

    Variation in the propagation delay for a 30 km TV (Line Ten) radio link was evaluated for a series of 30 independent measurements. Time marks from TV Channel 5 WTTG in Washington, D.C. were simultaneously measured at the Johns Hopkins University Applied Physics Laboratory and at the United States Naval Observatory against each stations' local cesium standard clocks. Differences in the stations' cesium clocks were determined by portable cesium clock transfers. Thirty independent timing determinations were made. The root mean square deviation in the propagation delay calculated from the timing determinations was 11 ns. The variations seen in the propagation delays are believed to be caused by environmental factors and by errors in the portable clock timing measurements. In correlating the propagation delay variations with local weather conditions, only a moderate dependence on air temperature and absolute humidity was found.

  1. Cambrian nepheline syenite complex at Jabal Sawda, Midyan region, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Liddicoat, W.K.; Ramsay, C.R.; Hedge, C.E.

    1986-01-01

    The only nepheline syenite complex presently known in the Arabian Shield is at Jabal Sawda, about 30 km S of Haql in the extreme NW of Saudi Arabia. It is a post-tectonic, composite intrusion with a crudely concentric structure. A core of leuco-nepheline syenite, a partial ring of mela-nepheline syenite, and an almost complete outer ring of alkali-feldspar syenite are the main rock units. Several mega-inclusions of porphyritic nepheline syenite, nepheline monzosyenite, malignite and ijolite are present in the leuco-nepheline syenite. The chemical composition is notable for very high values of Al2O3, Na2O, Ba, La, Nb, Sr and Zr. U{single bond}Pb isotope dating indicates an emplacement age of 553 ?? 4 Ma, one of an increasing number of reliable Cambrian isotope dates in the northern Red Sea region. ?? 1986.

  2. Effect of Road Adhesion Coefficient on Tractor-Semitrailer Cornering Braking Stability

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Li, Chen; Tang, Geteng; Wang, Cheng

    A dynamic model of tractor-semitrailer cornering braking was established in this paper, and the accuracy of the model was verified by real vehicle test. By model simulation of the cornering braking process, different road adhesion coefficient such as 0.15, 0.3, 0.45, 0.6, 0.75 was chosen to analyzed the changing curve of braking distance, articulation angle, yaw rate and lateral acceleration when initial speed of tractor-semitrailer was 30km h. The result showed that the peak values of articulation angle, yaw rate and lateral acceleration gotten by simulation were the largest. On the road of road adhesion coefficient 0.15, distance of tractor-semitrailer cornering braking was the longest. On the road of road adhesion coefficient 0.75, distance of tractor-semitrailer cornering braking was the shortest and the peak values of articulation angle, yaw rate and lateral acceleration were small relatively.

  3. Power spectra of mesospheric velocities in polar regions

    NASA Technical Reports Server (NTRS)

    Czechowsky, P.; Ruster, R.

    1985-01-01

    The mobile SOUSY radar was operated on Andoya in Northern Norway during the MAP/WINE campaign from November 1983 to February 1984 and for about two weeks in June 1984 to study the seasonal dependence of mesospheric structures and dynamics at polar latitudes. During the winter period, measurements were carried out on 57 days, primarily in coordination with the schedule of the rocket experiments. Echoes were detected in the troposphere and stratosphere up to 30 km and at mesospheric heights from about 50 to 90 km with a distinct maximum around noon. In summer, the radar system was operated continuously from 19th to the 28th of June 1984. Echoes occurred almost for 24 hours in the height range from 70 to 95 km showing no recognizable diurnal variation. Similar observations in polar latitudes were carried out for several years with the Poker Flat Radar in Alaska.

  4. Investigation of prototype volcano surveillance network

    NASA Technical Reports Server (NTRS)

    Eaton, J. P. (Principal Investigator); Ward, P. L.

    1973-01-01

    The author has identified the following significant results. Earthquake counters in Guatemala were being installed between February 13 and 17. The volcano Fuego began erupting ash and ash flows on February 23. On February 17, 6 days before the eruption there were 80 earthquakes at two counters 5 and 15 km from the volcano. This was a substantial increase of a fairly constant level of events per day recorded for the previous four days. A counter 30 km away did not show an increase. Had the DCP been operating longer and had the data been sent immediately from Goddard, it might have been possible to warn of a possible eruption six days in advance.

  5. Comparison of marine boundary layer cloud properties from CERES-MODIS Edition 4 and DOE ARM AMF measurements at the Azores

    NASA Astrophysics Data System (ADS)

    Xi, Baike; Dong, Xiquan; Minnis, Patrick; Sun-Mack, Sunny

    2014-08-01

    Marine boundary layer (MBL) cloud properties derived from the NASA Clouds and the Earth's Radiant Energy System (CERES) project using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data are compared with observations taken at the Department of Energy Atmospheric Radiation Measurement (ARM) Mobile Facility at the Azores (AMF-Azores) site from June 2009 through December 2010. Cloud properties derived from ARM ground-based observations were averaged over a 1 h interval centered at the satellite overpass time, while the CERES-MODIS (CM) results were averaged within a 30 km × 30 km grid box centered over the Azores site. A total of 63 daytime and 92 nighttime single-layered overcast MBL cloud cases were selected from 19 months of ARM radar-lidar and satellite observations. The CM cloud top/base heights (Htop/Hbase) were determined from cloud top/base temperatures (Ttop/Tbase) using a regional boundary layer lapse rate method. For daytime comparisons, the CM-derived Htop (Hbase), on average, is 0.063 km (0.068 km) higher (lower) than its ARM radar-lidar-observed counterpart, and the CM-derived Ttop and Tbase are 0.9 K less and 2.5 K greater than the surface values with high correlations (R2 = 0.82 and 0.84, respectively). In general, the cloud top comparisons agree better than the cloud base comparisons, because the CM cloud base temperatures and heights are secondary products determined from cloud top temperatures and heights. No significant day-night difference was found in the analyses. The comparisons of MBL cloud microphysical properties reveal that when averaged over a 30 km × 30 km area, the CM-retrieved cloud droplet effective radius (re) at 3.7 µm is 1.3 µm larger than that from the ARM retrievals (12.8 µm), while the CM-retrieved cloud liquid water path (LWP) is 13.5 gm-2 less than its ARM counterpart (114.2 gm-2) due to its small optical depth (9.6 versus 13.7). The differences are reduced by 50% when the CM averages are computed

  6. Long-term increase in Karenia brevis abundance along the Southwest Florida Coast

    PubMed Central

    Brand, Larry E.; Compton, Angela

    2008-01-01

    Data collected along the southwest coast of Florida between Tampa Bay and Sanibel Island on the abundance of the toxic dinoflagellate Karenia brevis from 1954 to 2002 were examined for spatial and temporal patterns. K. brevis was found to be approximately 20-fold more abundant within 5 km of the shoreline than 20-30 km offshore. Overall, K. brevis was approximately 13-18-fold more abundant in 1994-2002 than in 1954-1963. In 1954-1963, K. brevis occurred primarily in the fall months. In 1994-2002, it was more abundant not only in the fall, but also in the winter and spring months. It is hypothesized that greater nutrient availability in the ecosystem is the most likely cause of this increase in K. brevis biomass, and the large increase in the human population and its activities in South Florida over the past half century is a major factor. PMID:18437245

  7. Temporal, latitude and altitude absorbed dose dependences

    NASA Astrophysics Data System (ADS)

    Stozhkov, Y.; Svirzhevsky, N.; Bazilevskaya, G.

    The regular balloon measurements in the Earth's atmosphere are carried on at the Lebedev Physical Institute since 1957. The regular balloon flights have been made at the high latitude stations (near Murmansk - northern hemisphere and Mi ny -r Antarctica) and at the middle latitude (Moscow). Based on these long-term measurements as well as on the latitude data obtained in the several Soviet Antarctic expeditions the calculations of absorbed doses were fulfilled for altitudes of 10, 15, 20 and 30 km. The absorbed dose dependences on the geomagnetic cutoff rigidities and the phase of the 11-year solar cycle were found. The evaluation of the solar proton events and energetic electron precipitation contributions to the absorbed dose enhancements was made.

  8. Mössbauer study of two different aged rock types in the Vredefort structure, South Africa

    NASA Astrophysics Data System (ADS)

    Waanders, F. B.; Brink, M. C.; Bisschoff, A. A.

    2005-11-01

    The Vredefort Structure in South Africa was recently inscribed into the list of World Heritage sites as the oldest and largest recognised impact structure on earth. Due to upliftment of more than 30 km of the Archaean basement core and subsequent exposure of the deeply eroded central portion of the crater a unique opportunity exists to study rocks of the crust, especially those that have undergone recrystallization due to various thermal metamorphic events over time. Two rock types occurring in the central uplifted part of the impact structure were studied. One was a typical Archaean iron formation of sedimentary origin. The other rock studied, adjacent to this much older rock, is a homogeneous, medium grained recrystallized norite of immediately pre- or post-impact age, indicating a possible mafic igneous activity related to impact. Microscopy, XRD and Mössbauer analyses were performed on both samples.

  9. Monitoring of crustal movements in the San Andreas fault zone by a satellite-borne ranging system. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Kumar, M.

    1976-01-01

    The Close Grid Geodynamic Measurement System is conceived as an orbiting ranging device with a ground base grid of reflectors or transponders (spacing 1.0 to 30 km), which are projected to be of low cost (maintenance free and unattended), and which will permit the saturation of a local area to obtain data useful to monitor crustal movements in the San Andreas fault zone. The system includes a station network of 75 stations covering an area between 36 deg N and 38 deg N latitudes, and 237 deg E and 239 deg E longitudes, with roughly half of the stations on either side of the faults. In addition, the simulation of crustal movements through the introduction of changes in the relative positions between grid stations, weather effect for intervisibility between satellite and station and loss of observations thereof, and comparative evaluation of various observational scheme-patterns have been critically studied.

  10. Strong electric fields from positive lightning strokes in the stratosphere

    NASA Astrophysics Data System (ADS)

    Holzworth, R. H.; McCarthy, M. P.; Thomas, J. N.; Chin, J.; Chinowsky, T. M.; Taylor, M. J.; Pinto, O.

    2005-02-01

    A balloon payload launched in Brazil has measured vector electric fields from lightning at least an order of magnitude larger than previously reported above 30 km in the stratosphere. During the flight hundreds of lightning events were recorded, including several positive cloud to ground lightning strokes. A two stroke flash, with small (15 kA peak current) and moderate (53 kA) positive strokes at a horizontal range of 34 km, produced field changes over 140 V/m at 34 km altitude. On-board optical lightning detection, recorded with GPS timing, coupled with ground based lightning location gives high time resolution for study of the electric field transient propagation. These measurements imply that lightning electric fields in the mesosphere over large thunderstorms may be much larger than previously measured.

  11. The role of iron compounds in fixing heavy metals and arsenic in alluvial and soddy-podzolic soils in the Perm area

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Vasil'Ev, A. A.; Vlasov, M. N.; Korovushkin, V. V.

    2009-07-01

    In Perm, alluvial soils are strongly contaminated with heavy metals (Zn, Cu, and Ni, in particular) due to the ingress of liquid sewage. The concentration of a number of chemical elements is far higher in Fe-rohrensteins (tubular concretions around plant roots) of alluvial soils as compared to the fine earth. Ni and Cu are associated with Fe in rohrensteins of alluvial soils. The soddy-podzolic soils are in general less contaminated at a distance of 30 km to the northwest of Perm. Their contamination results from aerosols emitted by Perm industrial enterprises. Fe-Mn nodules that concentrate Ni and As are formed in hydromorphic podzolic soils. Mn oxides represent a separate phase carrying heavy metals and metalloids (manganophiles). Oxianions (As, Cr, and P) are closely bound to Fe in nodules, which are formed because of the alternating redox regime in soddy-podzolic soils. However, oxianions are not associated with Fe in rohrensteins of alluvial soils.

  12. Three-Dimensional Numerical Simulations of Equatorial Spread F: Results and Observations in the Pacific Sector

    NASA Technical Reports Server (NTRS)

    Aveiro, H. C.; Hysell, D. L.; Caton, R. G.; Groves, K. M.; Klenzing, J.; Pfaff, R. F.; Stoneback, R.; Heelis, R. A.

    2012-01-01

    A three-dimensional numerical simulation of plasma density irregularities in the postsunset equatorial F region ionosphere leading to equatorial spread F (ESF) is described. The simulation evolves under realistic background conditions including bottomside plasma shear flow and vertical current. It also incorporates C/NOFS satellite data which partially specify the forcing. A combination of generalized Rayleigh-Taylor instability (GRT) and collisional shear instability (CSI) produces growing waveforms with key features that agree with C/NOFS satellite and ALTAIR radar observations in the Pacific sector, including features such as gross morphology and rates of development. The transient response of CSI is consistent with the observation of bottomside waves with wavelengths close to 30 km, whereas the steady state behavior of the combined instability can account for the 100+ km wavelength waves that predominate in the F region.

  13. Examining the quasibiennial oscillation of total ozone and ozone concentrations at separate stratospheric levels according to data of TOMS satellite instrumentation

    NASA Astrophysics Data System (ADS)

    Bazhenov, O. E.; Makeev, A. P.

    2014-11-01

    The pattern of the quasibiennial oscillation of total ozone over northern territories of Russia (1996-2013) and ozone concentrations at separate stratospheric levels over Arctic sites (2005-2013) are analyzed according to data of TOMS satellite instrumentation. It is shown that the entire period of 1996-2013 can be divided into three intervals: before 2002- 2004, interval between 2002-2004 and 2008-2010, and period after 2008-2010. The quasibiennial oscillation is quite clearly manifested in the first and third periods and is distorted in the second period. The time series of the mixing ratio, composed for separate altitudinal levels, exhibit quasibiennial oscillation, which takes shape at heights of ~30 km and weakens in overlying regions.

  14. Kinetics of the reaction OH + H2O2 yields HO2 + H2O

    NASA Technical Reports Server (NTRS)

    Sridharan, U. C.; Reimann, B.; Kaufman, F.

    1980-01-01

    The paper describes an experimental study of the title reaction that uses the discharge-flow technique, laser-induced-fluorescence detection of OH and simultaneous monitoring of O and H atoms in the 250-459 K range. The reaction is normal and free from surface effect interference in Teflon or halocarbon wax-coated tube, but not in clean Pyrex. OH radicals are generated in three ways and at low concentrations to eliminate side reactions. The rate constants were determined at 298 K and over the 250-459 K range, with a factor of two higher at 298 K and factors of 3 to 5 higher at 10 to 30 km altitude in the terrestrial atmosphere than previous studies have indicated. The effect of the higher rate constant on atmospheric processes and on recent laboratory measurements of other reactions is also discussed.

  15. Comparison of Observed Temperature and Wind in Mountainous and Coastal Regions in Korea

    NASA Astrophysics Data System (ADS)

    Park, Y. S.

    2015-12-01

    For more than one year, temperature and wind are observed at several levels in three different environments in Korea. First site is located in a ski jump stadium in a mountain area and observations are performed at 5 heights. Second site is located in an agricultural land 1.4km inland from the seaside and the observing tower is 300m tall. Third site is located in the middle of sea 30km away from the seaside and the tower is 100m tall. The vertical gradients of air temperature are compared on the daily and seasonal bases. Not only the strengths of atmospheric stability are analyzed but also the times when the turnover of the signs of vertical gradients of temperature are occurred. The comparison is also applied to vertical gradients of wind speed and turning of wind direction due to surface slope and sea/land breeze. This study may suggest characteristics of local climate over different environments quantitatively.

  16. Airborne observations of the composition of the 1992 tropical stratosphere by FTIR solar absorption spectrometry

    NASA Technical Reports Server (NTRS)

    Toon, G. C.; Blavier, J.-F.; Solario, J. N.; Szeto, J. T.

    1993-01-01

    Vertical column measurements of the gaseous composition of the tropical stratosphere were made from the NASA DC-8 aircraft early in 1992. As anticipated, the burdens of the stratospheric source gases (e.g., O3, HF, HCl, ClNO3, HNO3) were reduced from their mid-latitude values due to increased uplift and photolysis. The tracers revealed considerably more uplift near the equator than the sub-tropics. For example, the HF burdens at +/- 20 deg latitude were nearly double those at 5 deg N. This, together with results obtained from other long-lived gases (e.g. N2O, CH4, CF2Cl2) indicates that volume mixing ratios found at 22 km altitude at mid-latitudes occurred at 26 km in the sub-tropics and at 30 km in the equatorial zone. This zone of uplift was symmetrical about the equator even though the sun was overhead at 20 deg S.

  17. Remote sensing and spectral analysis of plumes from ocean dumping in the New York Bight Apex

    NASA Technical Reports Server (NTRS)

    Johnson, R. W.

    1980-01-01

    The application of the remote sensing techniques of aerial photography and multispectral scanning in the qualitative and quantitative analysis of plumes from ocean dumping of waste materials is investigated in the New York Bight Apex. Plumes resulting from the dumping of acid waste and sewage sludge were observed by Ocean Color Scanner at an altitude of 19.7 km and by Modular Multispectral Scanner and mapping camera at an altitude of 3.0 km. Results of the qualitative analysis of multispectral and photographic data for the mapping, location, and identification of pollution features without concurrent sea truth measurements are presented which demonstrate the usefulness of in-scene calibration. Quantitative distributions of the suspended solids in sewage sludge released in spot and line dumps are also determined by a multiple regression analysis of multispectral and sea truth data.

  18. Satellite-Based Radar Measurements for Validation of Highresolution Sea State Forecast Models in the German Bight

    NASA Astrophysics Data System (ADS)

    Pleskachevsky, A.; Gebhardt, C.; Rosenthal, W.; Lehner, S.; Hoffmann, P.; Kieser, J.; Bruns, T.; Lindenthal, A.; Jansen, F.; Behrens, A.

    2015-04-01

    Remote sensing Synthetic Aperture Radar (SAR) data from TerraSAR-X and Tandem-X (TS-X and TD-X) satellites have been used for validation and verification of newly developed coastal forecast models in the German Bight of the North Sea. The empirical XWAVE algorithm for estimation of significant wave height has been adopted for coastal application and implemented for NRT services. All available TS-X images in the German Bight collocated with buoy measurements (6 buoys) since 2013 were processed and analysed (total of 46 scenes/passages with 184 StripMap images). Sea state estimated from series of TS-X images cover strips with length of ~200km and width of 30km over the German Bight from East-Frisian Islands to the Danish coast. The comparisons with results of wave prediction model show a number of local variations due to variety in bathymetry and wind fronts

  19. Observation of a solar flare at the limb with the Yohkoh Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Tsuneta, Saku; Hara, Hirohisa; Shimizu, Toshifumi; Acton, Loren W.; Strong, Keith T.; Hudson, Hugh S.; Ogawara, Yoshiaki

    1992-01-01

    A long-enduring soft X-ray flare at the solar limb was well observed by the Soft X-ray Telescope aboard the Yohkoh spacecraft from the preflare stage through the postflare phase. A 'helmet streamer' arch appears several hours prior to the flare, in association with a continuous expansion and restructuring of the active-region magnetic structure. This arch then starts to flare, and increases its height and footpoint separation at v = 10-30 km/s. The arch has a complex temperature structure in the rising phase, whereas the outer arches have systematically higher temperatures in the decay phase. Magnetic reconnection in a neutral sheet at the loop top, created by preflare magnetic restructuring, would explain this type of flare.

  20. Calculation of total effective dose equivalent and collective dose in the event of a LOCA in Bushehr Nuclear Power Plant.

    PubMed

    Raisali, G; Davilu, H; Haghighishad, A; Khodadadi, R; Sabet, M

    2006-01-01

    In this research, total effective dose equivalent (TEDE) and collective dose (CD) are calculated for the most adverse potential accident in Bushehr Nuclear Power Plant from the viewpoint of radionuclides release to the environment. Calculations are performed using a Gaussian diffusion model and a slightly modified version of AIREM computer code to adopt for conditions in Bushehr. The results are comparable with the final safety analysis report which used DOZAM code. Results of our calculations show no excessive dose in populated regions. Maximum TEDE is determined to be in the WSW direction. CD in the area around the nuclear power plant by a distance of 30 km (138 man Sv) is far below the accepted limits. Thyroid equivalent dose is also calculated for the WSW direction (maximum 25.6 mSv) and is below the limits at various distances from the reactor stack. PMID:16785243

  1. Observations of ELF propagation at high latitudes during the sporadic-e conditions of November 1986. Final report

    SciTech Connect

    Katan, J.R.; Saleem, D.J.

    1994-08-11

    Researchers in extremely low frequency (ELF) radio propagation have speculated on the effects of disturbed ionospheric conditions. Over the years, it has been observed that, although the propagation of ELF signals is remarkable for its relative stability, these signals are nevertheless influenced by many of the same types of disturbances that afflict higher frequency bands. Some of the early measurements revealed not only ELF's stable, predictive features (e.g., the smooth transitions through daytime and nighttime periods), but also its unexplainable, sudden decreases in nighttime signal strength. One of the most dramatic natural events for the radio propagationist to study is the solar proton event (SPE). During polar-cap absorption (PCA) events, an earthly response to an SPE, energetic protons from the sun penetrate the polar ionosphere. In the process, interactions with a variety of atmospheric constituents result in an increase in the ionization density to altitudes of 30 km or less.

  2. Observation of artificial spread-F and large region ionization enhancement in an HF heating experiment at HAARP

    NASA Astrophysics Data System (ADS)

    Kuo, Spencer; Snyder, Arnold

    2010-04-01

    A large-scale ionospheric modification by HF heaters was explored via HAARP digisonde operated in a fast mode. The results show that the ionogram virtual heights and the height spread of the ordinary-wave sounding echoes were changed significantly by the O-mode heater; the X-mode heater imposed no noticeable effect on the ionograms. The enhanced virtual height spread exceeds 40 km, more than 15% of sounding echo's average virtual height. The heater downshifted/upshifted the virtual height in the low/high frequency region around the heater frequency by as much as 15 and 7.5 km. The modifications were developing to last more than 10 seconds after the heater was turned off. The perturbed ionosphere took more than 60 seconds to recover. The modified electron density distribution indicates that the electron density and temperature increases exceed 10% and 25% over a large altitude region (>30 Km) from below to above the HF reflection height.

  3. The Tunguska event - No cometary signature in evidence

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.

    1983-01-01

    It is suggested that existing data on the 1908 Tunguska fall precludes an interpretation of the object as an either active or extinct comet fragment. Because a fireball of the Tunguska mass is not efficiently decelerated by the earth's atmosphere, it would at an entry velocity of about 30 km/sec have had to resist aerodynamic pressures greater than one billon dyn/sq cm before disintegrating. The inherently extremely fragile cometary material could not have survived a load of this magnitude. The data on Type II fireballs with prominent terminal flares are extrapolated, to estimate Tunguska's critical dynamic pressure at the same time of explosion as being of the order of 200 million dyn/sq cm, and its preexplosion velocity as about 10 km/sec, thereby ruling out a comet-like orbit. The Tunguska object is most consistently described as a small Apollo-type asteroid, 90-190 m across.

  4. Volatile inventory of Mars-2: Primordial sources and fractionating processes

    NASA Technical Reports Server (NTRS)

    Pepin, R. O.

    1987-01-01

    The total volatile inventory of Mars has been modeled using meteoritic and presumed primordial abundances in the early solar system. Evidence is presented which indicates that the elemental abundances of the noble gases on Earth and Mars are similar, and their ratios are comparable to those in average carbonaceous chondrites with the exception of xenon and krypton. In order to account for presently observed variations in gas abundances, two primordial sources were used. One was the solar composition similar to the solar wind, and the other of carbonaceous grains that were the source for trace exotic components. For Mars, a model in which the early, high solar EUV flux with continued hydrogen production by differentiation results in mass fractionation of the primordial atmosphere, early depletion of xenon, and later depletion of gases lighter than krypton. The result is that the primordial Mars water inventory may have been on the order of 20 to 30 km if spread over the planet.

  5. Solar wind interaction with small bodies. 1: Whistler wing signatures near to Gaspra and Ida

    NASA Technical Reports Server (NTRS)

    Wang, Z.; Kivelson, M. G.; Joy, S.; Khurana, K. K.; Polanskey, C.; Southwood, D. J.; Walker, R. J.

    1995-01-01

    Data from Galileo's two asteroid flybys reveal magnetic fluctuations that we interpret as perturbations of the solar wind magnetic field caused by an interaction with the nearby asteroid. The scale sizes of the bodies (approximately 14 km for Gaspra and approximately 30 km for Ida) are intermediate between the ion and electron gyroradii, which implies that the asteroid-imposed perturbations propagate in the whistler mode. Special properties of the whistler mode include phase phase velocities that can exceed the solar wind speed and confinement of the disturbance to directions nearly aligned with the magnetic field. These features of the interaction impose a structure on the solar wind disturbance that differs greatly from the forms familiar for either magnetized or unmagnetized bodies of magnetohydrodynamic spatial scales. We examine both data and computer simulations of the interaction with special attention to what can be inferred about the interaction itself from analysis of the data.

  6. DNS of Turbulent Boundary Layers under Highenthalpy Conditions

    NASA Astrophysics Data System (ADS)

    Duan, Lian; Martín, Pino

    2010-11-01

    To study real-gas effects and turbulence-chemistry interaction, direct numerical simulations (DNS) of hypersonic boundary layers are conducted under typical hypersonic conditions. We consider the boundary layer on a lifting-body consisting of a flat plate at an angle of attack, which flies at altitude 30km with a Mach number 21. Two different inclined angles, 35^o and 8^o, are considered,representing blunt and slender bodies. Both noncatalytic and supercatalytic wall conditions are considered. The DNS data are studied to assess the validity of Morkovin's hypothesis, the strong Reynolds analogy, as well as the behaviors of turbulence structures under high-enthalpy conditions.Relative to low-enthalpy conditions [1], significant differences in typical scalings are observed. [4pt] [1] L. Duan and I. Beekman and M. P. Mart'in, Direct numerical simulation of hypersonic turbulent boundary layers. Part 2: Effect of temperature, J. Fluid Mech. 655 (2010), 419-445.

  7. Two-dimensional model studies of the effect of supersonic aircraft operations on the stratospheric ozone content

    NASA Technical Reports Server (NTRS)

    Whitten, R. C.; Borucki, W. J.; Poppoff, I. G.; Latt, L.; Widhopf, G. F.; Capone, L. A.; Reigel, C. A.

    1981-01-01

    For a fleet of 250 aircraft, the change in the ozone column is predicted to be very close to zero; in fact, the ozone overburden may actually increase as a result of show that above 25 to 30 km the ozone abundance decreases via catalytic destruction, but at lower heights it increases, mainly as a result of coupling with odd hydrogen species. Water vapor released in the engine exhaust is predicted to cause ozone decreases; for the hypothetical engines used in the study, the total column ozone changes due to water vapor emission largely offset the predicted ozone increases due to NOx emission. The actual effect of water vapor may be less than calculated because present models do not include thermal feedback. Feedback refers to the cooling effect of additional water vapor that would tend to slow the NOx reactions which destroy ozone.

  8. A summary of niobium and rare earth localities from Ha'il and other areas in western Saudi Arabia: a preliminary study

    USGS Publications Warehouse

    Matzko, John J.; Naqvi, Mohammed Ibne

    1978-01-01

    Investigations in 1965 located veins containing radioactive material in the Halaban Group on the east side of a granite pluton at Jabal Aja near Ha'il. Later study extended the known area of radioactivity to a total length of about 30 km. Mineralogic studies indicated that the samples were low in uranium and that the radioactivity was due principally to thorium in niobium-bearing minerals. Two samples were reexamined to identify the sources of radioactivity, but X-ray and alpha plate studies did not reveal the radioactive minerals, even though uranium mineralization was indicated by the alpha plates. Further sampling is suggested to isolate the sources of radioactivity. This study indicates that niobium occurrences are related to alkaline intrusives in many areas of western Saudi Arabia. These areas should be investigated for their possible niobium and rare earth contents; their uranium content is apparently too low to be of economic interest.

  9. New Model of the Midcontinent Rift in Eastern Minnesota and Western Wisconsin

    NASA Astrophysics Data System (ADS)

    McSwiggen, Peter L.; Morey, G. B.; Chandler, Val W.

    1987-12-01

    The Midcontinent rift contains a central zone of mostly volcanic and associated intrusive rocks. Flanking, and in places overlying, these mafic igneous rocks are clastic sedimentary basins which range in thickness from less than 1.5 km southwest of the west end of Lake Superior to more than 3.0 km near the Minnesota-Iowa border. New gravity and magnetic modeling of the rift has shown that most of the volcanic and intrusive rocks are contained within a central block, which in Minnesota and Wisconsin extends to a depth of at least 10 to 20 km. The geometry of this central block, which ranges from fairly symmetric to very asymmetric, appears to reflect a change from predominantly a graben to only a half-graben development. The modeling has also suggested the presence of a major prerift intrusive body along the Minnesota-Iowa border which could have locally controlled the rift's development.

  10. Comparative study of two tsunamigenic earthquakes in the Solomon Islands: 2015 Mw 7.0 normal-fault and 2013 Santa Cruz Mw 8.0 megathrust earthquakes

    NASA Astrophysics Data System (ADS)

    Heidarzadeh, Mohammad; Harada, Tomoya; Satake, Kenji; Ishibe, Takeo; Gusman, Aditya Riadi

    2016-05-01

    The July 2015 Mw 7.0 Solomon Islands tsunamigenic earthquake occurred ~40 km north of the February 2013 Mw 8.0 Santa Cruz earthquake. The proximity of the two epicenters provided unique opportunities for a comparative study of their source mechanisms and tsunami generation. The 2013 earthquake was an interplate event having a thrust focal mechanism at a depth of 30 km while the 2015 event was a normal-fault earthquake occurring at a shallow depth of 10 km in the overriding Pacific Plate. A combined use of tsunami and teleseismic data from the 2015 event revealed the north dipping fault plane and a rupture velocity of 3.6 km/s. Stress transfer analysis revealed that the 2015 earthquake occurred in a region with increased Coulomb stress following the 2013 earthquake. Spectral deconvolution, assuming the 2015 tsunami as empirical Green's function, indicated the source periods of the 2013 Santa Cruz tsunami as 10 and 22 min.

  11. Crustal Heat Production and the Thermal Evolution of Mars

    NASA Technical Reports Server (NTRS)

    McLennan, Scott M.

    2001-01-01

    The chemical composition of soils and rocks from the Pathfinder site and Phobos-2 orbital gamma-ray spectroscopy indicate that the Martian crust has a bulk composition equivalent to large-ion lithophile (LIL) and heat-producing element (K, Th, U) enriched basalt, with a potassium content of about 0.5%. A variety of radiogenic isotope data also suggest that separation of LIL-enriched crust and depleted mantle reservoirs took place very early in Martian history (>4.0 Ga). Accordingly, if the enriched Martian crust is >30 km thick it is likely that a large fraction (up to at least 50%) of the heat-producing elements in Mars was transferred into the crust very early in the planet's history. This would greatly diminish the possibility of early widespread melting of the Martian mantle.

  12. Study of the technique of stellar occultation

    NASA Technical Reports Server (NTRS)

    Hays, P. B.; Graves, M. E.; Roble, R. G.; Shah, A. N.

    1973-01-01

    The results are reported of a study of the stellar occultation technique for measuring the composition of the atmosphere. The intensity of starlight was monitored during the occultation using the Wisconsin stellar ultraviolet photometers aboard the Orbiting Astronomical Observatory (OAO-A2). A schematic diagram of an occultation is shown where the change in intensity at a given wavelength is illustrated. The vertical projection of the attenuation region is typically 60 km deep for molecular oxygen and 30 km deep for ozone. Intensity profiles obtained during various occultations were analyzed by first determining the tangential columm density of the absorbing gases, and then Abel inverting the column densities to obtain the number density profile. Errors are associated with each step in the inversion scheme and have been considered as an integral part of this study.

  13. An oxygen isotope and geochemical study of meteoric-hydrothermal systems at Pilot Mountain and selected other localities, Carolina slate belt

    USGS Publications Warehouse

    Klein, T.L.; Criss, R.E.

    1988-01-01

    Several epigenetic mineral deposits in the Carolina slate belt are intimately related to meteoric-hydrothermal systems of late Precambrian and early Paleozoic age. At Pilot Mountain, low 18O rocks correlate well with zones of strong silicic alteration and alkali leaching accompanied by high alumina minerals (sericite, pyrophyllite, andalusite ?? topaz) and anomalous concentrations of Cu, Mo, Sn, B, and Au. A magmatic source for much of the sulfur and metal is likely, and a subordinate magmatic water component in the fluid of the central zone is possible. This central zone is surrounded by a >30 km2 peripheral zone of low 18O sericite schists, chlorite-sericite schists, and andesitic volcanic rocks. Reconnaissance studies of other alteration zones in the Carolina slate belt have so far disclosed the involvement of meteoric-hydrothermal fluids at the Snow Camp pyrophyllite deposit, at the Hoover Hill and Sawyer Au mines, and probably at the Haile and Brewer Au mines. -from Authors

  14. Closing of the Midcontinent-Rift - a far-field effect on Grenvillian compression

    USGS Publications Warehouse

    Cannon, W.F.

    1994-01-01

    The Midcontinent rift formed in the Laurentian supercontinent between 1109 and 1094 Ma. Soon after rifting, stresses changed from extensional to compressional, and the central graben of the rift was partly inverted by thrusting on original extensional faults. Thrusting culminated at about 1060 Ma but may have begun as early as 1080 Ma. On the southwest-trending arm of the rift, the crust was shortened about 30km; on the southeast-trending arm, strike-slip motion was dominant. The rift developed adjacent to the tectonically active Grenville province, and its rapid evolution from an extensional to a compressional feature at c1080 Ma was coincident with renewal of northwest-directed thrusting in the Grenville, probably caused by continent-continent collision. A zone of weak lithosphere created by rifting became the locus for deformation within the otherwise strong continental lithosphere. Stresses transmitted from the Grenville province utilized this weak zone to close and invert the rift. -Author

  15. Stabilized Photonic Links for Deep Space Tracking, Navigation, and Radio Science Applications

    NASA Technical Reports Server (NTRS)

    Huang, S.; Tjoelker, R. L.

    2012-01-01

    Stable fiber optic links have been operational in NASA's DSN for over 20 years providing distribution limited fractional frequency stability below 10-14 at one second and reaching 10-18 at approx 10,000 seconds. We summarize recent stabilized photonic link developments for DSN operation capable of high performance and reliability, and at much lower cost than previous systems. Recent research has focused on two applications, 1) actively stabilized links to transport 100 MHz metrology frequency references to sites up to 30 km from the central atomic frequency standard, and 2) stabilized links transporting broadband S, X, and Ka band signals used in deep space tracking and navigation and antenna arraying applications.

  16. Hydrocarbon geochemistry of hydrothermally generated petroleum from Escanaba trough, offshore Californi U.S.A.

    USGS Publications Warehouse

    Kvenvolden, K.A.; Rapp, J.B.; Hostettler, F.D.

    1990-01-01

    In 1986, three samples of sulfide-rich sediments, impregnated with hydrothermally derived, asphaltic petroleum, were recovered in a dredge and by submersible from Escanaba Trough, the sediment-covered, southern end of the Gorda Ridge spreading axis, offshore northern California. The molecular distributions of hydrocarbons in the two pyrrhotite-rich samples recovered by submersible are similar and compare well the hydrocarbon composition of the first pyrrhotite-rich samples containing petroleum discovered at a 1985 dredge site about 30 km to the south of the site of the submersible dive. In contrast, the 1986 dredge sample, composed of a polymetallic assemblage of sulfides, containes petroleum in which the distribution of hydrocarbons indicates a slightly higher of maturity relative to the other samples. The observation that petroleum of variable composition occurs with metallic sulfides at two and probably more distinct site indicates that petroleum generation may be a common process in the hydrothermally active Escanaba Trough. ?? 1990.

  17. A REVISED ASTEROID POLARIZATION-ALBEDO RELATIONSHIP USING WISE/NEOWISE DATA

    SciTech Connect

    Masiero, Joseph R.; Mainzer, A. K.; Bauer, J. M.; Wright, E. L.; McMillan, R. S.; Tholen, D. J.; Blain, A. W.

    2012-04-20

    We present a reanalysis of the relationship between asteroid albedo and polarization properties using the albedos derived from the Wide-field Infrared Survey Explorer. We find that the function that best describes this relation is a three-dimensional linear fit in the space of log (albedo)-log (polarization slope)-log (minimum polarization). When projected to two dimensions, the parameters of the fit are consistent with those found in previous work. We also define p* as the quantity of maximal polarization variation when compared with the albedo and present the best-fitting albedo-p* relation. Some asteroid taxonomic types stand out in this three-dimensional space, notably the E, B, and M Tholen types, while others cluster in clumps coincident with the S- and C-complex bodies. We note that both low albedo and small (D < 30 km) asteroids are underrepresented in the polarimetric sample, and we encourage future polarimetric surveys to focus on these bodies.

  18. Swarms: Optimum aggregations of spacecraft

    NASA Technical Reports Server (NTRS)

    Mayer, H. L.

    1980-01-01

    Swarms are aggregations of spacecraft or elements of a space system which are cooperative in function, but physically isolated or only loosely connected. For some missions the swarm configuration may be optimum compared to a group of completely independent spacecraft or a complex rigidly integrated spacecraft or space platform. General features of swarms are induced by considering an ensemble of 26 swarms, examples ranging from Earth centered swarms for commercial application to swarms for exploring minor planets. A concept for a low altitude swarm as a substitute for a space platform is proposed and a preliminary design studied. The salient design feature is the web of tethers holding the 30 km swarm in a rigid two dimensional array in the orbital plane. A mathematical discussion and tutorial in tether technology and in some aspects of the distribution of services (mass, energy, and information to swarm elements) are included.

  19. Gamma-Ray Flashes of Atmospheric Origin. The Compton Gamma-Ray Observatory Guest Investigator Program: Cycle 7

    NASA Technical Reports Server (NTRS)

    Mallozzi, Robert S.; Fishman, G. J.; Pendleton, G. N.; Inan, U. S.

    2000-01-01

    The BATSE detectors on the Compton Gamma-Ray Observatory have recorded the first observations of an unexplained terrestrial phenomenon: brief, intense flashes of MeV photons. These events, known as terrestrial gamma-ray flashes, must originate at altitudes above 30 km to be observed by the orbiting detectors. More than 70 of these events have been observed in nine years of observations. The most likely origin of these high-energy photons is bremsstrahlung from relativistic electrons from high altitude electrical discharges above thunderstorm regions. We proposed to analyze observations of temporal and spectral properties of these events, and to produce a catalog of event characteristics. Temporal correlations with radio observations made at Palmer Station, Antarctica and spatial correlations with satellite images of thunderstorm regions near GRO during these events were investigated, aiding in verification and testing of proposed theoretical models of the atmospheric processes believed to be responsible for these unique observations.

  20. The vulnerability of the Strait of Georgia (Canada) to future hypoxia and ocean acidification

    NASA Astrophysics Data System (ADS)

    Ianson, Debby; Allen, Susan; Moore-Maley, Ben; Haigh, Rowan; Johannessen, Sophia; Macdonald, Robie; Krogh, Jeremy; Simpson, Eleanor; Kohfeld, Karen; Hamme, Roberta

    2016-04-01

    The Canadian Pacific coast is filled with fjords and islands. Circulation in the region is dynamic, so that large changes in acidity (pH) and oxygen may occur both in space and time. The Strait of Georgia (Canada) is a large (200 X 30 km) semi-enclosed basin, that has relatively low pH with respect to the adjacent outer coast and yet hosts a lucrative aquaculture industry. On the other hand this region is relatively well oxygenated due to gas exchange in the turbulent (tidal) flow in the narrow Straits with sills connecting it with the outer coast. We investigate the role that this intense gas exchange plays in protecting the Strait of Georgia from future hypoxia and ocean acidification. Finally, we contrast surface water properties (including dissolved inorganic carbon and total alkalinity) measured on large ships with those measured nearshore and at shore-based aquaculture sites within the Strait.

  1. Troll oil pipeline: Seabed surveying and pipeline routing in critical areas

    SciTech Connect

    Indreeide, A.; Nilsen, O.; Trodal, L.; Canu, M.; Baldascino, G.

    1996-12-01

    The 85 km long 16-in oil pipeline from the Troll Field to the Mongstad Refinery North of Bergen in Norway, including a nearshore/inshore section of some 30 km length which is characterized by a water depth down to 540 meters, complex and rocky seabed topography including extremely steep fjords walls. This inner section required a considerable amount of highly detailed and accurate surveying, in particular using remotely operated vehicles (ROV) to gather the required seabed documentation for pipeline routing engineering and construction. In particular a high precision in route definition was necessary, together with a common seabed reference system for engineering and construction in order to obtain a very accurate pipeline location within the actual narrow route corridor. This paper deals with the seabed surveying and documentation as well as the subsequent pipeline routing within the nearshore/inshore section of the pipeline route.

  2. A 2D Microphysical Analysis of Aerosol Nucleation in the Polar Winter Stratosphere: Implications for H2SO4 Photolysis and Nucleation Mechanisms

    NASA Technical Reports Server (NTRS)

    Mills, Michael J.; Toon, Owen B.; Mills, Michael J.; Solomon, Susan

    1997-01-01

    Each spring a layer of small particles forms between 20 and 30 km in the polar regions. Results are presented from a 2D microphysical model of sulfate aerosol, which provide the first self-consistent explanation of the observed "CN layer." Photochemical conversion of sulfuric acid to SO2 in the upper stratosphere and mesosphere is necessary for this layer to form. Recent laboratory measurements of H2SO4 and SO3 photolysis rates are consistent with such conversion, though an additional source of SO2 may be required. Nucleation throughout the polar winter extends the top of the aerosol layer to higher altitudes, despite strong downward transport of ambient air. This finding may be important to heterogeneous chemistry at the top of the aerosol layer in polar winter and spring.

  3. Comparison of Marine Boundary Layer Cloud Properties from CERES-MODIS Edition 4 and DOE ARM AMF Measurements at the Azores

    NASA Technical Reports Server (NTRS)

    Xi, Baike; Dong, Xiquan; Minnis, Patrick; Sun-Mack, Sunny

    2014-01-01

    Marine boundary layer (MBL) cloud properties derived from the NASA Clouds and the Earth's Radiant Energy System (CERES) project using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data are compared with observations taken at the Department of Energy Atmospheric Radiation Measurement (ARM) Mobile Facility at the Azores (AMF-Azores) site from June 2009 through December 2010. Cloud properties derived from ARM ground-based observations were averaged over a 1 h interval centered at the satellite overpass time, while the CERES-MODIS (CM) results were averaged within a 30 km×30 km grid box centered over the Azores site. A total of 63 daytime and 92 nighttime single-layered overcast MBL cloud cases were selected from 19 months of ARM radar-lidar and satellite observations. The CM cloud top/base heights (Htop/Hbase) were determined from cloud top/base temperatures (Ttop/Tbase) using a regional boundary layer lapse rate method. For daytime comparisons, the CM-derived Htop (Hbase), on average, is 0.063 km (0.068 km) higher (lower) than its ARM radar-lidar-observed counterpart, and the CM-derived Ttop and Tbase are 0.9 K less and 2.5 K greater than the surface values with high correlations (R(sup 2) = 0.82 and 0.84, respectively). In general, the cloud top comparisons agree better than the cloud base comparisons, because the CM cloud base temperatures and heights are secondary products determined from cloud top temperatures and heights. No significant day-night difference was found in the analyses. The comparisons of MBL cloud microphysical properties reveal that when averaged over a 30 km× 30 km area, the CM-retrieved cloud droplet effective radius (re) at 3.7 micrometers is 1.3 micrometers larger than that from the ARM retrievals (12.8 micrometers), while the CM-retrieved cloud liquid water path (LWP) is 13.5 gm( exp -2) less than its ARM counterpart (114.2 gm( exp-2) due to its small optical depth (9.6 versus 13.7). The differences are reduced by 50

  4. The absence of satellites of asteroids

    NASA Astrophysics Data System (ADS)

    Gehrels, T.; Drummond, J. D.; Levenson, N. A.

    1987-05-01

    A CCD-imaging survey was made for satellites of minor planets at distances of about 0.1 to 7 arcmin from 1 Ceres, 2 Pallas, 4 Vesta, 6 Hebe, 7 Iris, 8 Flora, 15 Eunomia, 29 Amphitrite, 41 Daphne, and 44 Nysa, with cursory inspection of 192 Nausikaa. Satellites larger than 3 km were not found in this work, nor in previous photographic surveys. Not finding them appears to be consistent with theoretical studies of collisions in the asteroid belt by several authors. The satellites would have to be larger than at least 30 km to be collisionally stable. Taking tidal stability into account, it is concluded that the only possible satellites for main-belt asteroids are near-contact binaries. The only other rare possibility for a satellite might be a piece of debris from a recent collision.

  5. Nonlinear Strong Ground Motion in the 2004 Parkfield Earthquake

    NASA Astrophysics Data System (ADS)

    Rubinstein, J. L.; Beroza, G. C.

    2004-12-01

    Previous studies [Rubinstein and Beroza, 2004 (a,b); Schaff and Beroza, 2004] have shown that the strong shaking resultant from medium and large earthquakes can result in the formation and/or growth of microcracks in the near surface, resulting in reduced seismic velocities at distances exceeding 30km. We use moving window cross correlation on the waveforms of repeating earthquake sequences in the Parkfield area to identify temporal changes in wave propagation coincident with the earthquake, evidence of the damage that the Parkfield earthquake caused. The largest delays we observe are in the S coda, and exceed 10ms. Parkfield provides a unique opportunity where we can better understand to what depth damage caused by strong ground motion (nonlinear strong ground motion) occurs as there are many downhole and uphole seismometers in the region.

  6. RFI Mitigation for FAST

    NASA Astrophysics Data System (ADS)

    Zhang, Haiyan; Nan, Rendong; Gan, Hengqian; Yue, Youling; Wu, Mingchang; Zhang, Zhiwei; Jin, Chengjin; Peng, Bo

    2015-08-01

    Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a Chinese mega-science project to build the largest single dish radio telescope in the world. The construction was officially commenced in March 2011. The first light of FAST is expected in 2016. Due to the high sensitivity of FAST, Radio Frequency Interference (RFI) mitigation for the telescope is required to assure the realization of the scientific goals. In order to protect the radio environment of FAST site, the local government has established a radio quiet zone with 30 km radius. Moreover, Electromagnetic Compatibility (EMC) designs and measurements for FAST have also been carried out, and some examples, such as EMC designs for actuator and focus cabin, have been introduced briefly.

  7. Comparison of SAGE 2 ozone measurements and ozone soundings at Uccle (Belgium) during the period February 1985 to January 1986

    NASA Technical Reports Server (NTRS)

    Debacker, Hugo; Demuer, Dirk; Veiga, R. E.; Zawodny, J. M.

    1994-01-01

    The ozone profiles obtained from 24 balloon soundings, at 50 deg 48 min N, 4 deg 21 min E, carried out with the electro-chemical ozonesondes are discussed. The data were used as correlative data to the ozone profiles acquired by the Stratospheric Aerosol and Gas Experiment (SAGE 2). Good agreement was obtained between the two data sets. The difference of percentage between the ozone column density of the mean balloon and SAGE profile is 4.4% in the altitude region between 10 to 26 km. From the statistical analysis it seems that there is a difference between the mean profiles at the level of the ozone maximum and around the 30 km level. Similar results are obtained with an error analysis of both data. The differences between the mean profiles in the lower stratosphere are probably real, and are due to the presence of ozone.

  8. A study of regional waveform calibration in the eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Di Luccio, F.; Pino, N. A.; Thio, H. K.

    2003-06-01

    We modeled P nl phases from several moderate magnitude earthquakes in the eastern Mediterranean to test methods and develop path calibrations for determining source parameters. The study region, which extends from the eastern part of the Hellenic arc to the eastern Anatolian fault, is dominated by moderate earthquakes that can produce significant damage. Our results are useful for analyzing regional seismicity as well as seismic hazard, because very few broadband seismic stations are available in the selected area. For the whole region we have obtained a single velocity model characterized by a 30 km thick crust, low upper mantle velocities and a very thin lid overlaying a distinct low velocity layer. Our preferred model proved quite reliable for determining focal mechanism and seismic moment across the entire range of selected paths. The source depth is also well constrained, especially for moderate earthquakes.

  9. Modularization and installation, maintenance, and repair aspects of GASP technology

    SciTech Connect

    Dick, P. )

    1992-03-01

    This paper reports that the Goodfellow Assocs. Susbsea Processing (GASP) project addressed most of the major problem posed by the development of remote, small, marginal, or satellite oil and natural gas fields in deep waters. It considered a number of field development scenarios and , in particular, reviewed cases for fields situated up to 30 km from a platform- or shore-based processing facility. During the design of the resultant modularized GASP system, it was determined that an inspection, maintenance, and repair (IMR) philosophy needed to be developed. The number of field development scenarios involved, the different module dimensions and weights, and the remote driverless activities required in deeper waters resulted in a separate project, Maintenance and Retrieval Equipment (MARE).

  10. Influence of Idealized Heterogeneity on Wet and Dry Planetary Boundary Layers Coupled to the Land Surface. 1; Instantaneous Fields and Statistics

    NASA Technical Reports Server (NTRS)

    Houser, Paul (Technical Monitor); Patton, Edward G.; Sullivan, Peter P.; Moeng, Chin-Hoh

    2003-01-01

    This is the first in a two-part series of manuscripts describing numerical experiments on the influence of 2-30 km striplike heterogeneity on wet and dry boundary layers coupled to the land surface. The strip-like heterogeneity is shown to dramatically alter the structure of the free-convective boundary layer by inducing significant organized circulations that modify turbulent statistics. The coupling with the land-surface modifies the circulations compared to previous studies using fixed surface forcing. Total boundary layer turbulence kinetic energy increases significantly for surface heterogeneity at scales between Lambda/z(sub i) = 4 and 9, however entrainment rates for all cases are largely unaffected by the strip-like heterogeneity.

  11. The 1977 intertropical convergence zone experiment

    NASA Technical Reports Server (NTRS)

    Poppoff, I. G. (Editor); Page, W. A. (Editor); Margozzi, A. P. (Editor)

    1979-01-01

    Data are presented from the 1977 Intertropical Convergence Zone (ITCZ) Experiment conducted in the Panama Canal Zone in July 1977. Measurements were made daily over a 16-day period when the ITCZ moved across the Canal Zone. Two aircraft (Learjet and U-2) flew daily and provided data from horizontal traverses at several altitudes to 21.3 km of ozone, temperature, pressure, water vapor, aerosols, fluorocarbons, methane, nitrous oxide, nitric oxide, and nitric acid. Balloonsondes flown four times per day provided data on ozone, wind fields, pressure, temperature, and humidities to altitudes near 30 km. Rocketsondes provided daily data to altitudes near 69 km. Satellite photography provided detailed cloud information. Descriptions of individual experiments and detailed compilations of all results are provided.

  12. Determining Sources and Transport of Nuclear Contamination in Hudson River Sediments with Plutonium, Neptunium, and Cesium isotope ratios

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.; Chaky, D. A.; Simpson, H. J.; McHugh, C. M.; Shuster, E. L.; Bopp, R. F.

    2004-12-01

    Different sources of radioactive contamination contain characteristic and identifiable isotopic signatures, which can be used to study sediment transport. We focus on Pu-239, Pu-240, Np-237 and Cs-137, which are strongly bound to fine grained sediments. The Hudson River drainage basin has received contamination from at least three separate sources: 1) global fallout from atmospheric testing of nuclear weapons, which contributed Pu, Np and Cs; 2) contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River Estuary ˜70km north of New York Harbor, where records document releases of Cs-137; 3) contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, where incomplete records document releases of Cs-137 but no mention is made of Pu or Np. Here we report measurements of Pu isotopes, Np-237 and Cs-137 for a series of sediment cores collected from various locations within the drainage basin: 1) Mohawk River downstream of KAPL, 2) Hudson River upstream of its confluence with the Mohawk River, and 3) lower Hudson River at a location in close proximity to IPNPP. In addition, we present data from selected samples from two other lower Hudson River locations: One site located ˜30km downstream of IPNPP and another ˜30km upstream of IPNPP. By comparing the isotopic ratios Pu-240/Pu-239, Np-237/Pu-239, and Cs-137/Pu-239, measured in fluvial sediments to mean global fallout values, it is possible to identify and resolve different sources of non-fallout contamination. To date, isotopic data for sediments indicate non-fallout sources of Pu-239, Pu-240, and Cs-137; Np-237, however, appears to originate from global fallout only. Mohawk River sediments downstream of KAPL exhibit enrichments in Pu-239, Pu-240, and Cs-137 that are 7 to 20 times higher than levels expected from global fallout as indicated from Np-237. The elevated levels, non-fallout isotopic signatures

  13. Post-glacial lahars of the Sandy River Basin, Mount Hood, Oregon.

    USGS Publications Warehouse

    Cameron, K.A.; Pringle, P.

    1986-01-01

    Within the last 10 000 years, three significant lahar-producing periods have occurred at Mount Hood, Oregon. The Timberline eruptive period occurred between 1400 and 1800 years BP. It was by far the most voluminous of the three periods, producing enough clastic debris to bury the glacial topography of the southwest face of the mountain beneath a smooth debris fan. Timberline-age lahars traveled the length of the Zigzag and Sandy Rivers, a distance in excess of 90 km. Between 400 and 600 years BP, the Zigzag eruptive period produced deposits along the middle reaches of the Zigzag River and the upper Sandy River. The Old Maid eruptive period occurred between 180 and 270 years BP. A single lahar flowed down the Sandy River at least as far as Brightwood, 30 km from Crater Rock. -from Authors

  14. Optimization of an electromagnetic generator for strong shocks in low pressure gas

    NASA Astrophysics Data System (ADS)

    Larour, Jean; Singh, Raj Laxmi; Stehlé, Chantal; Ciardi, Andrea; Chaulagain, Uddhab; Suzuki-Vidal, Francisco

    2015-12-01

    In this paper, we present the design and optimization of an electromagnetic generator, able to produce strong shocks in noble gases, relevant to astrophysical conditions. It is a powerful accelerating device which ejects a quasi-planar plasma sheath out of a set of coaxial conical electrodes where a pulsed 100-kA current is passing. A simple model is used to optimize the operation parameters. Preliminary experiments show that the generator is capable of launching supersonic shocks in Argon, in the form of a thin plasma layer with the speed of ∼1-30 km/s. A three-dimension MHD simulation gives a description consistent with the model and with the observations.

  15. Effect of temperature coupling on ozone depletion prediction

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Butler, D. M.; Stolarski, R. S.

    1978-01-01

    The effects of chlorine perturbations on both the temperature and the ozone distribution in the stratosphere have been studied using a simplified radiative-photochemical model. The model solves the hydrostatic equation for total density in a self-consistent manner as the temperature is changed. Radiative coupling is found to have a significant effect on both the thermal structure and the ozone distribution, particularly in the 35-50-km region. By increasing the ClX mixing ratio by 5.0 ppbv, the temperature in this region is decreased by 5 to 10 K with a slight increase below 30 km. The local ozone depletion around 40 km due to added ClX is smaller compared with the estimate made by keeping the temperature fixed to the ambient condition. However, the integrated effect of radiative coupling is to increase the calculated column ozone depletion by 15% to 25% in this model.

  16. Energetic particle precipitation: A major driver of the ozone budget in the Antarctic upper stratosphere

    NASA Astrophysics Data System (ADS)

    Damiani, Alessandro; Funke, Bernd; Santee, Michelle L.; Cordero, Raul R.; Watanabe, Shingo

    2016-04-01

    Geomagnetic activity is thought to affect ozone and, possibly, climate in polar regions via energetic particle precipitation (EPP) but observational evidence of its importance in the seasonal stratospheric ozone variation on long time scales is still lacking. Here we fill this gap by showing that at high southern latitudes, late winter ozone series, covering the 1979-2014 period, exhibit an average stratospheric depletion of about 10-15% on a monthly basis caused by EPP. Daily observations indicate that every austral winter EPP-induced low ozone concentrations appear at about 45 km in late June and descend later to 30 km, before disappearing by September. Such stratospheric variations are coupled with mesospheric ozone changes also driven by EPP. No significant correlation between these ozone variations and solar ultraviolet irradiance has been found. This suggests the need of including the EPP forcing in both ozone model simulations and trend analysis.

  17. To see and not be seen

    NASA Astrophysics Data System (ADS)

    Fuller, K. L.

    1990-02-01

    The fundamental principles of military radars and electronic countermeasures against them are reviewed, with an emphasis on recent developments. Consideration is given to the radar equation, moving-target indication, electronic support measures (ESMs, comprising receiver, detector, identifier, and sorter), the choice of radar frequency, CW radars, tracking radars, FM CW radars, and channelized ESM receivers. Other countermeasures discussed include noise jamming, chaff, range-gate pull-off, and direct attack by homing missiles. An advanced FM CW tactical naval radar is described which is capable of frequency agility over a 50-MHz bandwidth and has a noise bandwidth of only 1 kHz (making it possible to reduce the transmitted power to 1 W); a typical naval EMS can detect this radar at a range of 2.5 km, as compared to 30 km for a conventional radar of similar performance.

  18. Determination of cloud effective particle size from the multiple-scattering effect on lidar integration-method temperature measurements.

    PubMed

    Reichardt, Jens; Reichardt, Susanne

    2006-04-20

    A method is presented that permits the determination of the cloud effective particle size from Raman- or Rayleigh-integration temperature measurements that exploits the dependence of the multiple-scattering contributions to the lidar signals from heights above the cloud on the particle size of the cloud. Independent temperature information is needed for the determination of size. By use of Raman-integration temperatures, the technique is applied to cirrus measurements. The magnitude of the multiple-scattering effect and the above-cloud lidar signal strength limit the method's range of applicability to cirrus optical depths from 0.1 to 0.5. Our work implies that records of stratosphere temperature obtained with lidar may be affected by multiple scattering in clouds up to heights of 30 km and beyond. PMID:16633433

  19. Physiological adjustments of young men to five-hour desert walks.

    PubMed

    Dill, D B; Soholt, L F; Oddershede, I B

    1976-02-01

    Seven young men undertook a desert walk of 30 km at a rate of 100 m/min. Six finished; the seventh stopped after 24 km. Each satisfied his thirst with cool tap water each hour. Periodic observations included metabolic rate, blood pressure, heart rate, rectal and skin temperature, body weight, and volume of water drunk. Hand sweat was collected each hour and body sweat residues on the skin were collected at the end of the walk. Subjective reports revealed portents of breakdown: aching muscles, painful joints, hot or blistered feet, hunger, and boredom. Cardiovascular adjustment and temperature regulation maintained tolerable conditions. The volumes of water evaporated by the 5-h walkers were about the same. Wet bulb temperatures were below 25 degrees C; all sweat evaporated and was available for temperature regulation. The volume of water drawn from body reserves was closely correlated with concentration of chloride in body sweat; the volume of water that satisfied thirst maintained osmotic pressure. PMID:1249002

  20. High resolution imaging of the Venus night side using a Rockwell 128x128 HgCdTe array

    NASA Technical Reports Server (NTRS)

    Hodapp, K.-W.; Sinton, W.; Ragent, B.; Allen, D.

    1989-01-01

    The University of Hawaii operates an infrared camera with a 128x128 HgCdTe detector array on loan from JPL's High Resolution Imaging Spectrometer (HIRIS) project. The characteristics of this camera system are discussed. The infrared camera was used to obtain images of the night side of Venus prior to and after inferior conjunction in 1988. The images confirm Allen and Crawford's (1984) discovery of bright features on the dark hemisphere of Venus visible in the H and K bands. Our images of these features are the best obtained to date. Researchers derive a pseudo rotation period of 6.5 days for these features and 1.74 microns brightness temperatures between 425 K and 480 K. The features are produced by nonuniform absorption in the middle cloud layer (47 to 57 Km altitude) of thermal radiation from the lower Venus atmosphere (20 to 30 Km altitude). A more detailed analysis of the data is in progress.

  1. Radiocarbon of dissolved humic substances in river waters from the Chernobyl area

    NASA Astrophysics Data System (ADS)

    Nagao, Seiya; Aramaki, Takafumi; Fujitake, Nobuhide; Matsunaga, Takeshi; Tkachenko, Yuri

    2004-08-01

    Radiocarbon (14C) was used to study the origin and transport of aquatic humic substances in river waters at the Chernobyl area, which received a pulse input of 14C as a consequence of the nuclear accident. Water samples were collected in April 1999 from the Pripyat and Sakhan Rivers, which flow through the radioactive contaminated area (30 km exclusion zone). The Δ14C values of humic and fulvic acids ranged from -68‰ to +75‰ and were ∼400‰ lower than those of non-contaminated environments. The aquatic humic substances may be derived mainly from those of bog, peat, and podzolic soil with older 14C age, and thereby reflect a larger proportion of older groundwater humic substances. Contribution of 14C by the Chernobyl accident appears to be small because of the long residence time of organic carbon at the surface soil.

  2. The Evolution of the Stratopause During the 2006 Major Warming: Satellite Data and Assimilated Meteorological Analyses

    NASA Technical Reports Server (NTRS)

    Manney, Gloria L.; Krueger, Kirstin; Pawson, Steven; Schwartz, Michael J.; Daffer, William H.; Livesey, Nathaniel J.; Remsberg, Ellis E.; Mlynczak, Martin G.; Russell, James M., III; Waters, Joe W.

    2007-01-01

    Microwave Limb Sounder and Sounding of the Atmosphere with Broadband Emission Radiometry data show the polar stratopause, usually higher than and separated from that at midlatitudes, dropping from <55-60 to near 30 km, and cooling dramatically in January 2006 during a major stratospheric sudden warming (SSW). After a nearly isothermal period, a cool stratopause reforms near 75 km in early February, then drops to <55 km and warms. The stratopause is separated in longitude as well as latitude, with lowest temperatures in the transition regions between higher and lower stratopauses. Operational assimilated meteorological analyses, which are not constrained by data at stratopause altitude, do not capture a secondary temperature maximum that overlies the stratopause or the very high stratopause that reforms after the SSW; they underestimate the stratopause altitude variation during the SSW. High-quality daily satellite temperature measurements are invaluable in improving our understanding of stratopause evolution and its representation in models and assimilation systems.

  3. Accelerated ions from pulsed-power-driven fast plasma flow in perpendicular magnetic field

    NASA Astrophysics Data System (ADS)

    Takezaki, Taichi; Takahashi, Kazumasa; Sasaki, Toru; Kikuchi, Takashi; Harada, Nob.

    2016-06-01

    To understand the interaction between fast plasma flow and perpendicular magnetic field, we have investigated the behavior of a one-dimensional fast plasma flow in a perpendicular magnetic field by a laboratory-scale experiment using a pulsed-power discharge. The velocity of the plasma flow generated by a tapered cone plasma focus device is about 30 km/s, and the magnetic Reynolds number is estimated to be 8.8. After flow through the perpendicular magnetic field, the accelerated ions are measured by an ion collector. To clarify the behavior of the accelerated ions and the electromagnetic fields, numerical simulations based on an electromagnetic hybrid particle-in-cell method have been carried out. The results show that the behavior of the accelerated ions corresponds qualitatively to the experimental results. Faster ions in the plasma flow are accelerated by the induced electromagnetic fields modulated with the plasma flow.

  4. Exploiting MODIS Observation Geometry To Identify Crop Specific Time Series For Regional Agriculture Monitoring

    NASA Astrophysics Data System (ADS)

    Duveiller, Gregory; Lopez-Lozano, Raul

    2013-12-01

    Due to its spatial resolution, the MODIS instrument offers much potential to monitor specific crops from space. However, only some time series fall adequately in the target crop specific fields while others straddle across different land uses, which consequently dilutes the signal. According to the daily change in orbit, the MODIS observation footprint changes considerably from one day to the next, sampling the vicinity of the grid cell. This study proposes a method to identify which time series are suitable based on the temporal signal-to-noise ratio (SNR) of such daily observations, which are acquired with different observation geometries. The approach is demonstrated over a 30 by 30 km study site in South Dakota (USA) where the time series with high SNR are classified in an unsupervised way into clusters almost exclusively composed of crop specific time series.

  5. Status of the Transneptunian Automated Occultation Survey (TAOS II)

    NASA Astrophysics Data System (ADS)

    Reyes-Ruiz, Mauricio

    2014-11-01

    TAOS II is a next generation occultation survey with the goal of measuring the size distribution of the small objects (diameters between 0.5 and 30 km) in the Kuiper Belt. The project is a collaboration between the Academia Sinica Institute of Astronomy and Astrophysics, the Universidad Nacional Autonoma de Mexico, and the Harvard-Smithsonian Center for Astrophysics, The survey will operate three 1.3 m telescopes at San Pedro Martir Observatory in Baja California, Mexico. Each telescope will be equipped with a custom camera comprising a focal plane array of CMOS imagers. Each camera will be capable of reading out image data from 10,000 stars at a cadence of 20 Hz. All telescopes will monitor the same set of stars simultaneously to search for coincident occultation events while minimizing the false positive rate. This poster describes the project and reports on the progress of the development of the survey infrastructure.

  6. Giotto-IMS observations of ion flow velocities and temperatures outside the contact surface of Comet Halley. [Ion Mass Spectrometer (IMS)

    NASA Technical Reports Server (NTRS)

    Goldstein, B. E.; Neugebauer, M.; Balsiger, H.; Drake, J.; Fuselier, S. A.; Goldstein, R.; Ip, WING-H.; Rettenmund, U.; Rosenbauer, H.; Schwenn, R.

    1986-01-01

    Fluid parameters for He(++) ions obtained from the Giotto ion mass spectrometer are presented. Proton densities and velocities and thermal speeds of protons, alpha particles, and heavy ions in the hour before closest approach are discussed. A region of enhanced He(++) ion densities, and velocity, and decreased temperature is observed from 20:26 to 21:45. Sharp decreases in the proton density are observed at 23:30 and at 23:41. There is a relative flow velocity between alpha particles and oxygen ions of 30 km/sec during a period from 22:55 to 23:30; the difference in flow velocity is less than the experimental uncertainities. The flow properties of protons observed during this period are also discussed.

  7. New radiosonde techniques to measure radiation profiles through the atmosphere

    NASA Astrophysics Data System (ADS)

    Kräuchi, Andreas; Philipona, Rolf; Romanens, Gonzague; Levrat, Gilbert

    2013-04-01

    Solar and thermal radiation fluxes are usually measured at Earth's surface and at the top of the atmosphere. Here we show radiosonde techniques that allow measuring radiation flux profiles and the radiation budget from the Earth's surface to above 30 km in the stratosphere. During two-hour flights solar shortwave and thermal longwave irradiance, downward and upward, is measured with four individual sensors at one-second resolution, along with standard PTU radiosonde profiles. Daytime and nighttime shortwave and longwave radiation measurements, and 24 hours surface measurements, allow determining radiation budget- and total net radiation profiles through the atmosphere. We use a double balloon technique to prevent pendulum motion during the ascent and to keep the sonde as horizontal as possible. New techniques using auto controlled airplanes are now investigated to retrieve the sonde after release at a certain altitude and to land it if possible at the launch station.

  8. Lidar Observations of the Pinatubo Stratospheric Aerosol Cloud over Frascati, Italy

    NASA Technical Reports Server (NTRS)

    Congeduti, Fernando; Adriani, Alberto; Gobbi, Gian Paolo; Centurioni, Sante

    1992-01-01

    The Pinatubo eruption of June 1991 introduced large plumes into the local stratosphere. On several occasions, volcanic gases and particles reached altitudes of about 30 km, and spread towards the west. A lidar system has been operating to monitor the evolution of the stratospheric aerosol cloud. The backscattering ratio profiles of eight different measurements were chosen to summarize the most significant occurrences of the event. Since the beginning of the winter planetary wave activity, the Pinatubo cloud integrated backscatter exceeded El Chichon's. In this context, the perturbation generated by El Chichon can only be assumed as a lower limit of the one which will follow the Pinatubo eruption. Observations of the event are still in progress.

  9. Slip history of the 2003 San Simeon earthquake constrained by combining 1-Hz GPS, strong motion, and teleseismic data

    USGS Publications Warehouse

    Ji, C.; Larson, K.M.; Tan, Y.; Hudnut, K.W.; Choi, K.

    2004-01-01

    The slip history of the 2003 San Simeon earthquake is constrained by combining strong motion and teleseismic data, along with GPS static offsets and 1-Hz GPS observations. Comparisons of a 1-Hz GPS time series and a co-located strong motion data are in very good agreement, demonstrating a new application of GPS. The inversion results for this event indicate that the rupture initiated at a depth of 8.5 km and propagated southeastwards with a speed ???3.0 km/sec, with rake vectors forming a fan structure around the hypocenter. We obtained a peak slip of 2.8 m and total seismic moment of 6.2 ?? 1018 Nm. We interpret the slip distribution as indicating that the hanging wall rotates relative to the footwall around the hypocenter, in a sense that appears consistent with the shape of the mapped fault trace. Copyright 2004 by the American Geophysical Union.

  10. Comparision between crustal density and velocity variations in Southern California

    USGS Publications Warehouse

    Langenheim, V.E.; Hauksson, E.

    2001-01-01

    We predict gravity from a three-dimensional Vp model of the upper crust and compare it to the observed isostatic residual gravity field. In general this comparison shows that the isostatic residual gravity field reflects the density variations in the upper to middle crust. Both data sets show similar density variations for the upper crust in areas such as the Peninsular Ranges and the Los Angeles basin. Both show similar variations across major faults, such as the San Andreas and Garlock faults in the Mojave Desert. The difference between the two data sets in regions such as the Salton Trough, the Eastern California Shear Zone, and the eastern Ventura basin (where depth to Moho is <30 km), however, suggests high-density middle to lower crust beneath these regions. Hence the joint interpretation of these data sets improves the depth constraints of crustal density variations.

  11. Melt water input from the Bering Glacier watershed into the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Josberger, Edward G.; Shuchman, Robert A.; Jenkins, Liza K.; Arthur Endsley, K.

    2014-02-01

    The annual runoff from the melting of large glaciers and snow fields along the northern perimeter of the Gulf of Alaska is a critical component of marine physical and biological systems; yet, most of this freshwater is not measured. Here we show estimates of melt for the watershed that contains the largest and longest glacier in North America, the Bering Glacier. The procedure combines in situ observations of snow and ice melt acquired by a long-term monitoring program, multispectral satellite observations, and nearby temperature measurements. The estimated melt is 40 km3 per melt season, ± 3.0 km3, observed over the decadal period, 2002-2012. As a result of climate change, these estimates could increase to 60 km3/yr by 2050. This technique and the derived melt coefficients can be applied to estimate melt from Alaska to Washington glaciers.

  12. A seismic survey of the Manson disturbed area

    NASA Technical Reports Server (NTRS)

    Sendlein, L. V. A.; Smith, T. A.

    1971-01-01

    The region in north-central Iowa referred to as the Manson disturbed area was investigated with the seismic refraction method and the bedrock configuration mapped. The area is approximately 30 km in diameter and is not detectable from the surface topography; however, water wells that penetrate the bedrock indicate that the bedrock is composed of disturbed Cretaceous sediments with a central region approximately 6 km in diameter composed of Precambrian crystalline rock. Seismic velocity differences between the overlying glacial till and the Cretaceous sediments were so small that a statistical program was developed to analyze the data. The program developed utilizes existing 2 segment regression analyses and extends the method to fit 3 or more regression lines to seismic data.

  13. The Martian impact cratering record

    NASA Technical Reports Server (NTRS)

    Strom, Robert G.; Croft, Steven K.; Barlow, Nadine G.

    1992-01-01

    A detailed analysis of the Martian impact cratering record is presented. The major differences in impact crater morphology and morphometry between Mars and the moon and Mercury are argued to be largely the result of subsurface volatiles on Mars. In general, the depth to these volatiles may decrease with increasing latitude in the southern hemisphere, but the base of this layer may be at a more or less constant depth. The Martial crustal dichotomy could have been the result of a very large impact near the end of the accretion of Mars. Monte Carlo computer simulations suggest that such an impact was not only possible, but likely. The Martian highland cratering record shows a marked paucity of craters less than about 30 km in diameter relative to the lunar highlands. This paucity of craters was probably the result of the obliteration of craters by an early period of intense erosion and deposition by aeolian, fluvial, and glacial processes.

  14. Change in statistics of drought in a land use scenario for Brazil

    NASA Astrophysics Data System (ADS)

    Kilian, Markus; Chavez, Erik; Lucarini, Valerio

    2016-04-01

    The land use changes due to an intensified and expanding agricultural and industrial activity is affecting regional weather and climate in Brazil. We analyse the results of a land use change driven Weather and Research Forecasting Model (WRF) using classical drought indices and specific agricultural yield loss drought optimum indices. The objective is to assess changes in risk exposure driven by changes in weather patterns subject to different scenarios of land use changes in Brazil. The WRF model is driven by land use changes as well as the ECHAM5 climate model (with the A1B scenario) on a 60km and 30km grid. In order to determine the risk exposure of an important economic sector to changes in land use change we focus on maize as one of the principal crop grown in Brazil.

  15. Conductivity and electric field variations with altitude in the stratosphere

    NASA Technical Reports Server (NTRS)

    Holzworth, Robert H.

    1991-01-01

    Data regarding electric field, derived current density, and conductivity are presented for two balloons from the Electrodynamics of the Middle Atmosphere experiment which underwent the longest period of daily altitude variation. The magnetic L values range from 4.3 to 9.5 for the 18 days of Southern Hemisphere statistics, and the average conductivity and vertical electric fields are given. Simultaneous measurements of the average conductivity scale height and the vertical electric-field scale height indicate that vertical current density does not vary with altitude in the 10-28-km range. The measured conductivity varies significantly at a given altitude on a particular day, and some conductivity data sets are similar to other measurements between 10 and 30 km. Comparisons of the measured data to predictions from models of stratospheric conductivity demonstrate significant discrepancies.

  16. Thunderstorm related variations in stratospheric conductivity measurements

    NASA Technical Reports Server (NTRS)

    Hu, Hua; Holzworth, Robert H.; Li, Ya QI

    1989-01-01

    The vector electric field and polar conductivities were measured by zero-pressure balloon-borne payloads launched from Wallops Island, Virgina during the summers of 1987 and 1988. Data were collected over thunderstorms (or electrified clouds) during 6-hour flights at altitudes near 30 km. The vector electric field measurements were made with the double Langmuir probe high-impedance method, and the direct conductivity measurements were obtained with the relaxation technique. Evidence is presented for conductivity variations over thunderstorms (or electrified clouds). It is found that both positive and negative polar conductivity data do show variations of up to a factor of 2 from ambient values associated with the disturbed periods. Some ideas for possible physical mechanisms which may be responsible for the conductivity variations over thunderstorms are also discussed in this paper.

  17. Precision estimation in temperature and refractivity profiles retrieved by GPS radio occultations

    NASA Astrophysics Data System (ADS)

    Alexander, P.; Torre, A.; Llamedo, P.; Hierro, R.

    2014-07-01

    The Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) is a six-satellite Global Positioning System (GPS) radio occultation (RO) mission that started in April 2006. The close proximity of these satellites during some months after launch provided a unique opportunity to evaluate the precision of GPS RO temperature and refractivity profile retrievals in the neutral atmosphere from nearly collocated and simultaneous observations. In order to work with nearly homogeneous sets, data are divided into five groups according to latitude bands during 20 days of July. For all latitude bands and variables, the best precision values (about 0.1%) are found somewhere between 8 and 25 km height. In general, we find that precision degrades significantly with height above 30 km and its performance becomes there worse than 1%. Temperature precision assessment has been generally excluded in previous studies. Refractivity has here, in general, a precision similar to dry temperature but worse than wet temperature in the lower atmosphere and above 30 km. However, it has been shown that the better performance of wet temperature is an artificial effect produced by the use of the same background information in nearly collocated wet retrievals. Performance in refractivity around 1% is found in the Northern Hemisphere at the lowest heights and significantly worse in the southern polar zone above 30 km. There is no strong dependence of the estimated precision in terms of height on day and night, on latitude, on season, or on the homogeneity degree of each group of profiles. This reinforces the usual claim that GPS RO precision is independent of the atmospheric conditions. The roughly 0.1% precision in the 8-25 km height interval should suffice to distinguish between day and night average values, but no significant differences are found through a Student t test for both populations at all heights in each latitude band. It was then shown that the present spatial

  18. Evidence of ongoing crustal deformation related to magmatic activity near Socorro, New Mexico

    NASA Technical Reports Server (NTRS)

    Larsen, S.; Brown, L.; Reilinger, R.

    1986-01-01

    Leveling measurements conducted in 1980-1981 by the National Geodetic Survey in the Socorro area of the Rio Grande rift are analyzed. Crustal uplift related to magma inflation in the midcrustal magma body is detected; an uplift of 0.18 cm/yr is measured for the time between 1951-1980. The survey data of 1911 and 1959 are compared to the present data and good correlation is observed. The systematic leveling errors including height-dependence and refraction errors are studied. The 30-km-wide subsidence in the area is examined. The spatial correlation between seismic activity, the Socorro magma body, and crustal deformation in Socorro is investigated. The crustal movement from magma reservior activities is modeled using the formulations of Dieterich and Decker (1975). The modeling of the deformation reveals that the movement in the Socorro area is associated with the 19-km deep Socorro magma body.

  19. Structural Data for the Columbus Salt Marsh Geothermal Area - GIS Data

    DOE Data Explorer

    Faulds, James E.

    2011-12-31

    Shapefiles and spreadsheets of structural data, including attitudes of faults and strata and slip orientations of faults. - Detailed geologic mapping of ~30 km2 was completed in the vicinity of the Columbus Marsh geothermal field to obtain critical structural data that would elucidate the structural controls of this field. - Documenting E‐ to ENE‐striking left lateral faults and N‐ to NNE‐striking normal faults. - Some faults cut Quaternary basalts. - This field appears to occupy a displacement transfer zone near the eastern end of a system of left‐lateral faults. ENE‐striking sinistral faults diffuse into a system of N‐ to NNE‐striking normal faults within the displacement transfer zone. - Columbus Marsh therefore corresponds to an area of enhanced extension and contains a nexus of fault intersections, both conducive for geothermal activity.

  20. Analysis and Optimization of a Piezoelectric Harvester on a Car Damper

    NASA Astrophysics Data System (ADS)

    Lafarge, B.; Delebarre, C.; Grondel, S.; Curea, O.; Hacala, A.

    Low power levels obtained from piezoelectric conversion of ambient vibrations appear to be a promising solution to supply wireless sensors embedded inside automotive suspension. However such a solution requires overall an optimum power extraction from the piezoelectric power harvester. This leads to the use of a sufficiently accurate and flexible modelling method to find the optimal characterics and configuration of the harvester. To this end, an innovative bond graph model of the piezoelectric harvester embedded in the quarter vehicle system is proposed for providing the harvested power when a car travels a road with a speed bump at 30 km/h. Results show that around of 0.5 milliwatt electrical power is harvested when varying key parameters like the location and characteristics of the piezoelectric device.

  1. TOWARD A NEW GEOMETRIC DISTANCE TO THE ACTIVE GALAXY NGC 4258. III. FINAL RESULTS AND THE HUBBLE CONSTANT

    SciTech Connect

    Humphreys, E. M. L.; Reid, M. J.; Moran, J. M.; Greenhill, L. J.; Argon, A. L.

    2013-09-20

    We report a new geometric maser distance estimate to the active galaxy NGC 4258. The data for the new model are maser line-of-sight (LOS) velocities and sky positions from 18 epochs of very long baseline interferometry observations, and LOS accelerations measured from a 10 yr monitoring program of the 22 GHz maser emission of NGC 4258. The new model includes both disk warping and confocal elliptical maser orbits with differential precession. The distance to NGC 4258 is 7.60 {+-} 0.17 {+-} 0.15 Mpc, a 3% uncertainty including formal fitting and systematic terms. The resulting Hubble constant, based on the use of the Cepheid variables in NGC 4258 to recalibrate the Cepheid distance scale, is H{sub 0} = 72.0 {+-} 3.0 km s{sup -1} Mpc{sup -1}.

  2. Infrared observations of circumstellar ammonia in OH/IR supergiants

    NASA Technical Reports Server (NTRS)

    Mclaren, R. A.; Betz, A. L.

    1980-01-01

    Ammonia has been detected in the circumstellar envelopes of VY Canis Majoris, VX Sagittarii, and IRC +10420 by means of several absorption lines in the nu-2 vibration-rotation band near 950 kaysers. The line profiles are well resolved (0.2 km/sec resolution) and show the gas being accelerated to terminal expansion velocities near 30 km/sec. The observations reveal a method for determining the position of the central star on VLBI maps of OH maser emission to an accuracy of approximately 0.2 arcsec. A firm lower limit of 2 x 10 to the 15th/sq cm is obtained for the NH3 column density in VY Canis Majoris.

  3. Shear wave velocity variation across the Taupo Volcanic Zone, New Zealand, from receiver function inversion

    USGS Publications Warehouse

    Bannister, S.; Bryan, C.J.; Bibby, H.M.

    2004-01-01

    The Taupo Volcanic Zone (TVZ), New Zealand is a region characterized by very high magma eruption rates and extremely high heat flow, which is manifest in high-temperature geothermal waters. The shear wave velocity structure across the region is inferred using non-linear inversion of receiver functions, which were derived from teleseismic earthquake data. Results from the non-linear inversion, and from forward synthetic modelling, indicate low S velocities at ???6- 16 km depth near the Rotorua and Reporoa calderas. We infer these low-velocity layers to represent the presence of high-level bodies of partial melt associated with the volcanism. Receiver functions at other stations are complicated by reverberations associated with near-surface sedimentary layers. The receiver function data also indicate that the Moho lies between 25 and 30 km, deeper than the 15 ?? 2 km depth previously inferred for the crust-mantle boundary beneath the TVZ. ?? 2004 RAS.

  4. SHIELD II: WSRT HI Spectral Line Observations

    NASA Astrophysics Data System (ADS)

    Gordon, Alex Jonah Robert; Cannon, John M.; Adams, Elizabeth A.; SHIELD II Team

    2016-01-01

    The "Survey of HI in Extremely Low-mass Dwarfs II" ("SHIELD II") is a multiwavelength, legacy-class observational campaign that is facilitating the study of both internal and global evolutionary processes in low-mass dwarf galaxies discovered by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We present new results from WSRT HI spectral line observations of 22 galaxies in the SHIELD II sample. We explore the morphology and kinematics by comparing images of the HI surface densities and the intensity weighted velocity fields with optical images from HST, SDSS, and WIYN. In most cases the HI and stellar populations are cospatial; projected rotation velocities range from less than 10 km/s to roughly 30 km/s.Support for this work was provided by NSF grant AST-1211683 to JMC at Macalester College, and by NASA through grant GO-13750 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555.

  5. Steady state risetimes of shock waves in the atmosphere

    NASA Technical Reports Server (NTRS)

    Raspet, Richard; Bass, Henry; Yao, Lixin; Wu, Wenliang

    1992-01-01

    A square wave shape is used in the Pestorius algorithm to calculate the risetime of a step shock in the atmosphere. These results agree closely with steady shock calculations. The healing distance of perturbed shocks due to finite wave effects is then investigated for quasi-steady shocks. Perturbed 100 Pa shocks require on the order of 1.0 km travel distance to return to within 10 percent of their steady shock risetime. For 30 Pa shocks, the minimum recovery distance increases to 3.0 km. It is unlikely that finite wave effects can remove the longer risetimes and irregular features introduced into the sonic boom by turbulent scattering in the planetary boundary layer.

  6. Comparison of Temperature and Ozone Measured by the AROTEL Instrument on DC8 Overflights of Ny Aalesund during the SOLVE Mission

    NASA Technical Reports Server (NTRS)

    Hoegy, Walter R.; McGee, Thomas J.; Burris, John F.; Heaps, William; Silbert, Donald; Sumnicht, Grant; Twigg, Laurence; Neuber, Roland

    2000-01-01

    The AROTEL instrument, deployed on the NASA DC-8 at Kiruna, Sweden for the SAGE III Ozone Loss and Validation Experiment (SOLVE), flew over the NDSC station operated by the Alfred Wegner Institute at Ny Aalesund, Spitsbergen. AROTEL ozone and temperature measurements made during near overflights of Ny Aalesund are compared with sonde ozone and temperature, and lidar ozone measurements from the NDSC station. Nine of the seventeen science flights during the December through March measurement period overflew near Ny Aalesund. Agreement of AROTEL with the ground-based temperature and ozone values at altitudes from just above the aircraft to about 30 km gives strong confidence in using AROTEL temperature and ozone mixing ratio to study the mechanisms of ozone loss in the winter arctic polar region.

  7. Long Term Sea Level Changes in the Falkland Islands

    NASA Astrophysics Data System (ADS)

    Woodworth, P. L.; Pugh, D. T.

    2009-04-01

    In 1842, James Clark Ross measured sea levels at Port Louis, 30 km NW of Port Stanley in the Falkland Islands, over a period of 8 months. The benchmarks with respect to which the levels were measured have been perfectly preserved, and in 2009 a new series of sea level measurements was made at the same site. In addition, a set of GPS measurements was made at Port Louis and Port Stanley, where there is a permanent modern tide gauge. The collected measurements enable us to estimate the average rate of sea level change in the area since 1842 with an accuracy of approximately 0.4 mm/year. This is one of the few estimates of long term sea level change in the southern hemisphere. This poster will describe how the measurements were made and will present some of the first results.

  8. Peculiar high energy cosmic ray stratospheric event reveals a heavy primary origin particle above the knee region of the cosmic ray spectrum

    SciTech Connect

    Kopenkin, V.; Fujimoto, Y.

    2005-01-15

    We wish to put forward an explanation for a peculiar cosmic ray event with energy {sigma}E{sub {gamma}}{>=}2x10{sup 15} eV detected in 1975 by the balloon borne emulsion chamber experiment performed in the stratosphere, at the altitude {>=}30 km above sea level. For almost 30 years the event has been described as unusual, invoking new exotic mechanisms or models. In our opinion there is no need for an extraordinary explanation. Contrary to the widespread belief, the event gives us an example of 'unrecognized standard physics'. At the same time this event revealed a variety of features which are of considerable interest for cosmic rays, nuclear physics, and astrophysics. Here we show that the observed family is most likely to be a result of a heavy nucleus interaction with an air nucleus. In this case a primary particle would originally have been in the energy region above 'the knee' of the cosmic ray spectrum.

  9. Large transverse momenta in nuclear interaction at E{sub 0} > 10{sup 16} eV detected in stratosphere

    SciTech Connect

    Managadze, A. K. Osedlo, V. I.; Roganova, T. M.; Sveshnikova, L. G.; Galkin, V. I.; Rakobolskaya, I. V.; Goncharova, L. A.; Kotelnikov, K. A.; Polukhina, N. G.

    2007-01-15

    A gamma-hadron superfamily of cosmic-rays created by a primary cosmic-ray particle with energy above 10{sup 16} eV was detected at an altitude of 30 km by a stratospheric balloon-borne emulsion chamber. Being of superhigh energy, this event is the unique example in the world statistics of practically pure nuclear interactions in the energy range unattainable for modern accelerators. The present analysis allowed one to estimate the interaction height above the chamber and transverse momenta of the secondaries produced in the interaction. The mean value of transverse momenta appears to be very large ( > 2.5 GeV/c)

  10. Plasmadynamic hypervelocity dust injector for the National Spherical Torus Experiment

    NASA Astrophysics Data System (ADS)

    Ticoş, Cǎtǎlin M.; Wang, Zhehui; Dorf, Leonid A.; Wurden, Glen A.

    2006-10-01

    The design and construction of a plasmadynamic device to accelerate dust to hypervelocities is presented. High speed dust will be used to measure magnetic field lines in the National Spherical Torus Experiment. The plasma gun produces a high density (ne≈1018cm-3) and low temperature (a few eV) deuterium plasma, ejected by J ×B forces which provide drag on the dust particles in its path. The dust will be entrained by the plasma to velocities of 1-30km/s, depending on the dust mass. Carbon dust particles will be used, with diameters from 1to50μm. The key components of the plasmadynamic accelerator are a coaxial plasma gun operated at 10kV (with an estimated discharge current of 200kA), a dust dispenser activated by a piezoelectric transducer, and power and remote-control systems.

  11. An instrument to measure the spectrum of cosmic ray iron and other nuclei to above 100 GeV/nucleon

    NASA Technical Reports Server (NTRS)

    Arens, J. F.; Balasubrahmanyan, V. K.; Ormes, J. F.; Siohan, F.; Schmidt, W. K. H.; Simon, M.; Spiegelhauer, H.

    1979-01-01

    A balloon-borne instrument system for the study of cosmic ray composition in the energy region beyond 100 GeV/nucleon is described. The large area detector incorporates an ionization spectrometer or calorimeter to determine the energy of the incident particles which is calibrated in flight by a gas Cerenkov counter filled with freon 12 at 20 psi. Calibration of calorimeter response indicates that the effects of ionization energy loss and nucleon fragmentation are correctly accounted for in a Monte Carlo simulation. A charge measuring module consisting of five scintillators and a lucite Cerenkov counter is used to determine the charge and position of the incoming particles. A spatial resolution of 5 to 10 cm has been obtained by using the ratios of pulse heights in different photomultiplier tubes aimed at the same scintillators within the module. The detector represents the heaviest cosmic ray experiment that can be flown over 30 km using the dynamic launching technique commonly employed.

  12. Formaldehyde Surface Distributions and Variability in the Mexico City Basin

    NASA Astrophysics Data System (ADS)

    Junkermann, W.; Mohr, C.; Steinbrecher, R.; Ruiz Suarez, L.

    2007-05-01

    Formaldehyde ambient air mole fractions were measured throughout the dry season in March at three different locations in the Mexico City basin. The continuously running instruments were operated at Tenago del Aire, a site located in the Chalco valley in the southern venting area of the basin, at the Intituto Mexicano del Petroleo (IMP) in the northern part of the city and about 30 km north of the city at the campus of the Universidad Tecnològica de Tecamac (UTTEC). The technique used is the Hantzsch technology with a time resolution of 2 minutes and a detection limit of 100 ppt. Daily maxima peaked at 35 ppb formaldehyde in the city and about 15 to 20 ppb at the other sites. During night formaldehyde levels dropped to about 5 ppb or less. It is evident that the observed spatial and temporal variability in near surface formaldehyde distributions is strongly affected by local and regional advection processes.

  13. Ground testing of the HyShot supersonic combustion flight experiment in HEG

    NASA Astrophysics Data System (ADS)

    Gardner, A. D.; Hannemann, K.; Pauli, A.; Steelant, J.

    The first phase of the HyShot supersonic combustion ramjet (scramjet) flight exper- iment program of The University of Queensland in Australia was designed to provide benchmark data on supersonic combustion for a flight Mach number of approximately M=8. The second flight of the HyShot program, performed on July 30th 2002, was successful and supersonic com- bustion was observed along the specified trajectory range. The operating range of the High Enthalpy Shock Tunnel Göttingen (HEG) of the German Aerospace Centre (DLR) was recently extended. The facility has now the capability of testing a complete scramjet engine with internal combustion and external aerodynamics at M=7.8 flight conditions in altitudes of about 30 km. A post flight analysis of the HyShot flight experiment was performed using an operational scramjet wind tunnel model with a geometry which is identical to that of the flight configuration.

  14. Topography of sinuous rilles in the Harbinger Mountains region of the moon

    NASA Technical Reports Server (NTRS)

    Strain, P. L.; El-Baz, F.

    1977-01-01

    Five sinuous rilles in mare basalts in the Harbinger Mountains region of the moon are described. Rille length ranges from 12 to 79 km, width from 0.8 to 4.8 km, and depth from 100 to 300 m. The rilles appear to become shallower to the north, while the southern ends are characterized by circular-to-elongate depressions that occur on a 30-km-in-diameter dome of probable volcanic origin. Longitudinal profiles show that the rille floors have a northward slope of less than one deg, consistent with the general slope of the surrounding mare surface. Structural studies indicate that slope, rather than the regional structural pattern, is the dominant factor controlling rill direction. Topographic data support the theory that the rilles were formed as lave channels or tubes.

  15. Global disturbances of the ionosphere caused by the electric field from the high-altitude nuclear explosion 'Starfish' on July 9, 1962. I, II

    NASA Astrophysics Data System (ADS)

    Tsedilina, E. E.; Shashun'kina, V. M.

    1990-10-01

    The theory of the formation of an artifical radiation belt of high-energy electrons in the magnetosphere is used to examine possible ionospheric effects from the electric field generated by the Starfish nuclear test explosion over Johnston Island on July 9, 1962. A region in the Northern Hemisphere is identified where the explosion led to a drop in electron density in the F-region maximum by about 20 percent and a lowering of the layer by 20-30 km in the course of one hour after the explosion. The F-layer gradually came back to normal in the following hour. It is suggested that, in the initial period after the explosion, this effect was associated with the western electric field, which caused the lowering of the F-layer, as well as with changes in the recombination-diffusion balance in this layer.

  16. Observation of ionospheric disturbances following a 5-kt chemical explosion. II - Prolonged anomalies and stratifications in the lower thermosphere after shock passage

    NASA Astrophysics Data System (ADS)

    Blanc, Elisabeth; Jacobson, Abram R.

    1989-12-01

    Unusual stratifications and prolonged spectral deformations of radio echoes after the passage through the E region of the shock wave produced by a 5-kt chemical explosion have been observed. The observations were obtained by vertical HF pulsed ionospheric sounding. At the total reflection level of the sounding waves, at a horizontal distance of 30 km from the explosion, the passage of the shock wave generated a complex structure suggesting a significant deformation of the reflecting surface. Irregularities have also been observed in the E region for over 30 min after the shock passage by a network of continuous wave HF ionospheric sounders located 250 km west of the source. The origin of these structures is discussed.

  17. High resolution Halpha spectroscopy and R-band photometry of Swift J1357.2-0933

    NASA Astrophysics Data System (ADS)

    Casares, Jorge; Torres, Manuel A. P.; Negueruela, Ignacio; Gonzalez-Fernandez, Carlos; Corral-Santana, Jesus M.; Zurita, Cristina; Llano, Sergio Rodriguez

    2011-03-01

    We report on high resolution Halpha spectroscopy and time-resolved photometry of the optical counterpart to the X-ray transient Swift J1357.2-0933 in outburst (Krimm et al. ATEL #3138). SPECTROSCOPY: Six 30-33 min spectra were obtained on the nights of 2011 Feb 25-27 using the IDS Spectrograph on the 2.5m Isaac Newton Telescope (INT) at the Observatorio del Roque de Los Muchachos. The observations were performed with the H1800V grating and a slit width 1.6 arcsec to yield a spectral coverage of 6270-7000 Angs with a 30 km/s FWHM spectral resolution at Halpha..

  18. Aftershocks of the December 7, 2012 intraplate doublet near the Japan Trench axis

    NASA Astrophysics Data System (ADS)

    Obana, Koichiro; Kodaira, Shuichi; Nakamura, Yasuyuki; Sato, Takeshi; Fujie, Gou; Takahashi, Tsutomu; Yamamoto, Yojiro

    2014-12-01

    On December 7, 2012, a pair of large Mw 7.2 intraplate earthquakes occurred near the Japan Trench axis off Miyagi, northeast Japan. This doublet consisted of a deep reverse-faulting event followed by a shallow normal-faulting event. Aftershock observations using conventional and newly developed ultra-deep ocean bottom seismographs in the trench axis area showed that the shallow normal-faulting event occurred in the subducting Pacific plate just landward of the trench axis. The shallow normal-faulting aftershock activity indicated that in-plate tension in the incoming/subducting Pacific plate extends to a depth of at least 30 km, which is deeper than before the 2011 Tohoku-Oki earthquake, whereas in-plate compression occurs at depths of more than 50 km. Hence, we concluded that the neutral plane of the in-plate stress is located between depths of 30 and 50 km near the trench axis.

  19. [Accidents of the Fukushima Daiichi Nuclear Power Plants and future].

    PubMed

    Hoshi, Masaharu

    2012-01-01

    A massive earthquake of magnitude 9 terribly happened far out at sea of Tohoku area on 11 March, 2011. After this earthquake the hugest tsunami in the history came to the hundreds km of the seashore of Tohoku area. Due to this tsunami all of the four nuclear power plants of Fukushima Daiichi lost every electric power and, soon after this, loss nuclear fuels from number 1 to 3 reactors melt through their power containers. According to this phenomena, large amount of the radio-activities have been released in the air. There were some releases but major contaminations happened at the time of the two releases in the morning of 15 March, 2011. Due to this, to the direction of the northwest until the Iitate Village over 30km zone was contaminated. In this paper I explain the time course of the accidents and that how contaminated. PMID:24568025

  20. Plume-lithosphere interaction beneath a fast moving plate

    NASA Astrophysics Data System (ADS)

    Thoraval, Catherine; Tommasi, Andréa; Doin, Marie-Pierre

    2006-01-01

    Two-dimensional numerical simulations of mantle convection with temperature and pressure dependent viscosity are used to study plume-lithosphere interaction beneath a fast moving plate. Plumes behavior and, hence, their erosional and melting potential, depend on the Rayleigh number and plume buoyancy flux. Analysis of the balance between large-scale and plume-induced flow and of the ability of the plume to melt allows to put bounds on the upper mantle viscosity (1020, 1021 Pas), on the plumes diameter (<200 km) and temperature anomaly (200-400°C). Within this range of parameters, strongly time-dependent small-scale instabilities form in the plume-lithosphere boundary layer. They lead to thermal rejuvenation of the lithosphere downstream from the plume. The 1200°C isotherm is raised by up to 30km, but the 800°C isotherm is hardly moved, leading to a steep transient geotherm at the base of the plate.

  1. Neotectonics, geodesy, and seismic hazard in the Northern Walker Lane of Western North America: Thirty kilometers of crustal shear and no strike-slip?

    NASA Astrophysics Data System (ADS)

    Wesnousky, Steven G.; Bormann, Jayne M.; Kreemer, Corné; Hammond, William C.; Brune, James N.

    2012-05-01

    Roughly 30 km of cumulative right-lateral crustal displacement and 5-6 mm/yr of the ongoing relative right-lateral motion between the Pacific and North American plates are observed in the northern Walker Lane. The right-lateral shear has been accommodated in large part by the development of a set of discontinuous, en echelon, normal fault-bounded basins and perhaps significant vertical axis rotations of the intervening crust. The observations provide an illustrative example of how large amounts of crustal shear may be accommodated in the absence of strike-slip faults and point to difficulties attendant to melding geologic and geodetic observations in the analysis of seismic hazard. In this particular case, the assumption that all geodetically observed shear across the area will be recorded by earthquake displacements may be flawed.

  2. Novel wavelength division multiplex-radio over fiber-passive optical network architecture for multiple access points based on multitone generation and triple sextupling frequency

    NASA Astrophysics Data System (ADS)

    Cheng, Guangming; Guo, Banghong; Liu, Songhao; Huang, Xuguang

    2014-01-01

    An innovative wavelength division multiplex-radio over fiber-passive optical network architecture for multiple access points (AP) based on multitone generation and triple sextupling frequency is proposed and demonstrated. A dual-drive Mach-Zehnder modulator (DD-MZM) is utilized to realize the multitone generation. Even sidebands are suppressed to make the adjacent frequency separation twice the frequency of the local oscillator by adjusting the modulation voltage of the DD-MZM. Due to adopting three fiber Bragg gratings to reflect the unmodulated sidebands for uplink communications source free at optical network unit (ONU), is achieved. The system can support at least three APs at one ONU simultaneously with a 30 km single-mode fiber (SMF) transmission and 5 Gb/s data rate both for uplink and downlink communications. The theoretical analysis and simulation results show the architecture has an excellent performance and will be a promising candidate in future hybrid access networks.

  3. Regional Elevations in the Southern Hemisphere of Mars From the Mars Orbiter Laser Altimeter

    NASA Technical Reports Server (NTRS)

    Smith, D. E.; Zuber, M. T.; Frey, H. V.; Garvin, J. B.; Head, J. W.; Muhleman, D. O.; Neumann, G. A.; Pettengill, G. H.; Phillips, R. J.; Solomon, S. C.

    1999-01-01

    The Mars Orbiter Laser Altimeter (MOLA) is an instrument on the Mars Global Surveyor (MGS) spacecraft that is currently providing the first high vertical and spatial resolution topographic measurements of surface elevations on Mars. The shot size in the mapping orbit is about 100 m and the shot-to-shot spacing is 330 m. The instrument has a vertical precision of 37.5 cm and a vertical accuracy that depends on the radial accuracy of the MGS orbit that is currently in the range 5-30 km. The initial focus on observations in the nominal mapping mission will be on the southern hemisphere, which was not sampled during the MGS aerobraking hiatus and Science Phasing orbits. During the first several weeks of global mapping there will be emphasis on producing a digital terrain model (DTM) of the Mars '98 landing site.

  4. Estimated SAGE II ozone mixing ratios in early 1993 and comparisons with Stratospheric Photochemistry, Aerosols and Dynamic Expedition measurements

    NASA Technical Reports Server (NTRS)

    Yue, G. K.; Veiga, R. E.; Poole, L. R.; Zawodny, J. M.; Proffitt, M. H.

    1994-01-01

    An empirical time-series model for estimating ozone mixing ratios based on Stratospheric Aerosols and Gas Experiment II (SAGE II) monthly mean ozone data for the period October 1984 through June 1991 has been developed. The modeling results for ozone mixing ratios in the 10- to 30- km region in early months of 1993 are presented. In situ ozone profiles obtained by a dual-beam UV-absorption ozone photometer during the Stratospheric Photochemistry, Aerosols and Dynamics Expedition (SPADE) campaign, May 1-14, 1993, are compared with the model results. With the exception of two profiles at altitudes below 16 km, ozone mixing ratios derived by the model and measured by the ozone photometer are in relatively good agreement within their individual uncertainties. The identified discrepancies in the two profiles are discussed.

  5. Rapid and widespread dispersal of flood sediment on the northern California margin

    USGS Publications Warehouse

    Wheatcroft, R.A.; Sommerfield, C.K.; Drake, D.E.; Borgeld, J.C.; Nittrouer, C.A.

    1997-01-01

    The dispersal of flood sediment from small river systems is a poorly studied, yet potentially important aspect of active continental-margin sedimentation. In January 1995, during a flood with a 30 yr return period, the Eel River (northern California) delivered an estimated 25 ?? 3 ?? 106 t (metric tons) of tine-grained (<62 ??m) sediment to the ocean. The flood formed a distinct layer on the sea bed that was centered on the 70 m isobath, extended for 30 km along shelf and 8 km across shelf, and was as thick as 8.5 cm, but contained only 6 ?? 106 t of sediment. Thus, 75% of the flood-derived sediment did not form a recount/able deposit, but was instead rapidly and widely dispersed over the continental margin. Stratigraphic models of, and compilations of sediment flux to, active continental margins need to take the dispersive nature of small river systems into account.

  6. Database for the Geologic Map of Newberry Volcano, Deschutes, Klamath, and Lake Counties, Oregon

    USGS Publications Warehouse

    Bard, Joseph A.; Ramsey, David W.; MacLeod, Norman S.; Sherrod, David R.; Chitwood, Lawrence A.; Jensen, Robert A.

    2013-01-01

    Newberry Volcano, one of the largest Quaternary volcanoes in the conterminous United States, is a broad shield-shaped volcano measuring 60 km north-south by 30 km east-west with a maximum elevation of more than 2 km. Newberry Volcano is the product of deposits from thousands of eruptions, including at least 25 in the past approximately 12,000 years (Holocene Epoch). Newberry Volcano has erupted as recently as 1,300 years ago, but isotopic ages indicate that the volcano began its growth as early as 0.6 million years ago. Such a long eruptive history and recent activity suggest that Newberry Volcano is likely to erupt in the future. This geologic map database of Newberry Volcano distinguishes rocks and deposits based on their composition, age, and lithology.

  7. Reinterpretation of the stratigraphy and structure of the Rancho Las Norias area, central Sonora, Mexico

    NASA Astrophysics Data System (ADS)

    Page, William R.; Harris, Anita G.; Poole, Forrest G.; Repetski, John E.

    2003-12-01

    New geologic mapping and fossil data in the vicinity of Rancho Las Norias, 30 km east of Hermosillo, Sonora, Mexico, show that rocks previously mapped as Precambrian instead are Paleozoic. Previous geologic maps of the Rancho Las Norias area show northeast-directed, southwest-dipping reverse or thrust faults deforming both Precambrian and Paleozoic rocks. The revised stratigraphy requires reinterpretation of some of these faults as high-angle normal or oblique-slip faults and the elimination of other faults. We agree with earlier geologic map interpretations that compressional structures have affected the Paleozoic rocks in the area, but our mapping suggests that the direction of compression is from southeast to northwest.

  8. Simulation of CO2 release at 800 km altitude. Technical report

    SciTech Connect

    Setayesh, A.

    1993-08-31

    The SOCRATES contamination-interaction code has been used to simulate the reactions of O + CO2 --> CO2(v) + O, O + CO2 - CO(v) + O2, and CO2 + H - CO + OH(v) at an altitude of 800 km in both ram and wake directions of the spacecraft. These simulations show that the radiation from these reactions can be measurable for the parameters which have been used in these calculations. The investigation carries out the simulations as much as 30 km from the spacecraft. The radiative intensity of CO(v) and OH(v) show the highest and lowest, respectively. Gas plume, CO2, CO, and OH Emissions, Monte Carlo method, Rarefied flows.

  9. The analysis of GEOS-3 altimeter data in the Tasman and Coral seas

    NASA Technical Reports Server (NTRS)

    Mather, R. S.

    1977-01-01

    A technique was developed for preprocessing GEOS-3 altimetry data to establish a model of the regional sea surface. The algorithms developed models for a 35,000,000 sq km area with an internal precision of + or - 1 m. There were discrepancies between the sea surface model so obtained and GEM6 based geoid profiles with wavelengths of approximately 2500 km and amplitudes of up to 5 m in this region. The amplitudes were smaller when compared with GEM10-based geoid determinations. However, the comparison of 14 pairs of overlapping passes in the region indicated altimeter resolution of the + or - 25 cm level if the wavelength corresponding to the Nyquist frequency were 30 km. The spectral analysis of such comparisons indicated the existence of significant signal strength in the discrepancies after least squares fitting, with wavelengths in excess of 200 km.

  10. Io: Generation of Silicate Magma by Shear Melting at the Base of a Basaltic Lithosphere

    NASA Technical Reports Server (NTRS)

    Carr, M. H.

    1985-01-01

    Tidal theory and observational evidence indicates that about 1 w/sq. m. of energy is released at the surface of Io. In order to place limits on how much tidal energy can be dissipated within a rigid lithosphere, depth-temperature profiles were calculated for different lithosphere thickness assuming that the tidal energy was dissipated uniformly throughout the lithosphere. Thus a thick lithosphere implies that a significant fraction of the tidal energy is dissipated below the depth where solidus temperatures are reached. One possibility is that Io has a crust consisting of a low melting temperature fraction such as basalt, overlying a mantle of a high melting temperature fraction such as peridotite. Thus, if the lithosphere of Io is thicker than 30 km, as appears probable, then high rates of silicate volcanism are implied and a significant fraction of the tidal energy must be dissipated by viscous deformation rather than rigid flexure.

  11. Atmospheric structure measurements from accelerometer instrumented falling spheres

    NASA Astrophysics Data System (ADS)

    Philbrick, C. R.; McIsaac, J. P.; Fryklund, D. H.; Buck, R. F.

    1981-12-01

    A three axis piezoelectric accelerometer, mounted in a 25 cm diameter sphere was used to measure atmospheric density and winds and to obtain a temperature profile in the altitude range from 50 to 150 km. The sphere with its own telemetry system and beacon transponder was released from a rocket at 70 km altitude on the up leg of the flight. The drag acceleration measured by the accelerometer can be used to directly calculate the atmospheric density with a vertical resolution of 100 m. The wind field is calculated, assuming uniform distribution in the horizontal plane between the up and down leg regions, which are 30 km apart. The atmospheric temperature profile is determined by integrating along the density profile, assuming ideal gas law conditions and hydrostatic equilibrium. The profiles obtained from the density, temperature and wind profiles can be used to describe those regions of the atmosphere expected to be statically and dynamically unstable.

  12. Detection of the CO (J = 7 = 6) rotational transition at lambda = 0. 37 millimeters toward Orion

    SciTech Connect

    Schultz, G.V.; Durwen, E.J.; Roeser, H.P.; Wattenbach, R.; Sherwood, W.A.

    1985-04-01

    The J = 7 = 6 rotational transition of carbon monoxide has been detected toward the Kleinmann-Low nebula. The peak antenna temperature is 110 + or - 35 K centered at V(LSR) = + 5 km/s; the FWHM line width is 35 + or - 5 km/s, and its optical depth is not greater than 0.3. The integrated intensity of the line between - 20 and + 30 km/s leads to a total flux density of (2.5 + or - 0.5) x 10 to the -14th W/sq m in a beam of 35 + or - 5 arsec. No spike feature is seen at + 9 km/s. 22 references.

  13. Numerical exploration of mixing and combustion in ethylene fueled scramjet combustor

    NASA Astrophysics Data System (ADS)

    Dharavath, Malsur; Manna, P.; Chakraborty, Debasis

    2015-12-01

    Numerical simulations are performed for full scale scramjet combustor of a hypersonic airbreathing vehicle with ethylene fuel at ground test conditions corresponding to flight Mach number, altitude and stagnation enthalpy of 6.0, 30 km and 1.61 MJ/kg respectively. Three dimensional RANS equations are solved along with species transport equations and SST-kω turbulence model using Commercial CFD software CFX-11. Both nonreacting (with fuel injection) and reacting flow simulations [using a single step global reaction of ethylene-air with combined combustion model (CCM)] are carried out. The computational methodology is first validated against experimental results available in the literature and the performance parameters of full scale combustor in terms of thrust, combustion efficiency and total pressure loss are estimated from the simulation results. Parametric studies are conducted to study the effect of fuel equivalence ratio on the mixing and combustion behavior of the combustor.

  14. A catalog of rotational and radial velocities for evolved stars. V. Southern stars

    NASA Astrophysics Data System (ADS)

    De Medeiros, J. R.; Alves, S.; Udry, S.; Andersen, J.; Nordström, B.; Mayor, M.

    2014-01-01

    Rotational and radial velocities have been measured for 1589 evolved stars of spectral types F, G, and K and luminosity classes IV, III, II, and Ib, based on observations carried out with the CORAVEL spectrometers. The precision in radial velocity is better than 0.30 km s-1 per observation, whereas rotational velocity uncertainties are typically 1.0 km s-1 for subgiants and giants and 2.0 km s-1 for class II giants and Ib supergiants. Based on observations collected at the Haute-Provence Observatory, Saint-Michel, France, and at the European Southern Observatory, La Silla, Chile.Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/561/A126

  15. Stratospheric ozone and hydroxyl radical measurements by balloon-borne lidar

    NASA Technical Reports Server (NTRS)

    Heaps, W. S.; Mcgee, T. J.; Hudson, R. D.; Caudill, L. O.

    1982-01-01

    An experiment is reported in which a balloon-borne lidar system was used to measure ozone and the hydroxyl radical in the stratosphere by two lidar techniques. Ozone was measured in the 20-37 km altitude range using differential absorption lidar, and the hydroxyl radical was measured in the 34-37 km range using remote laser-induced fluorescence. Ozone concentrations were determined with a vertical resolution of 0.5 km, and in addition, horizontally resolved ozone measurements with 0.15-km resolution were obtained over a 2-km range. The temporal variation of the hydroxyl radical concentration ranged from 40 parts/trillion shortly after noon to about 5 parts/trillion two hours after sunset. Possible modifications to the system are discussed which can yield an improvement in the sensitivity of between one and two orders of magnitude, thus permitting measurements of the hydroxyl radical in the 20-30-km altitude range.

  16. Hypersonic Flow Control Using Upstream Focused Energy Deposition

    NASA Technical Reports Server (NTRS)

    Riggins David W.; Nelson, H. F.

    1999-01-01

    A numerical study of centerline and off-centerline power deposition at a point upstream of a two-dimensional blunt body at Mach 6.5 at 30 km altitude are presented. The full Navier-Stokes equations are used. Wave drag, lift, and pitching moment are presented as a function of amount of power absorbed in the flow and absorption point location. It is shown that wave drag is considerably reduced. Modifications to the pressure distribution in the flow field due to the injected energy create lift and a pitching moment when the injection is off-centerline. This flow control concept may lead to effective ways to improve the performance and to stabilize and control hypersonic vehicles.

  17. The response of stratospheric constituents to a solar eclipse, sunrise, and sunset

    NASA Technical Reports Server (NTRS)

    Herman, J. R.

    1979-01-01

    The use of measurements combined with detailed stratospheric modeling of time dependent events, to confirm chemical mechanisms and their laboratory rate constants, is examined. Careful simultaneous solutions of these equations have shown a significant daytime variation of ozone down to altitudes of about 30 km that can affect the interpretation of spectral absorption type experiments. The calculated sunset variations of NO and HO show a log linear concentration decay for limited time periods that can be readily converted into atmospheric temperatures by using known reaction rates up to about 70-km altitude. Proposed measurements of the time dependent behavior of NO and NO2 to be made by U2 aircraft at 20-km altitude are also discussed.

  18. Fiskenaesset Anorthosite Complex: Stable isotope evidence for shallow emplacement into Archean ocean crust

    SciTech Connect

    Peck, W.H.; Valley, J.W.

    1996-06-01

    Oxygen and hydrogen isotope ratios indicate that unusual rocks at the upper contact of the Archean Fiskenaesset Anorthosite Complex at Fiskenaesset Harbor (southwest Greenland) are the products of hydrothermal alteration by seawater at the time of anorthosite intrusion. Subsequent granulite-facies metamorphism of these Ca-poor and Al- and Mg-rich rocks produced sapphirine- and kornerupine-bearing assemblages. Because large amounts of surface waters cannot penetrate to depths of 30 km during granulite-facies metamorphism, the isotopic signature of the contact rocks must have been obtained prior to regional metamorphism. The stable isotope and geochemical characteristics of the contact rocks support a model of shallow emplacement into Archean ocean crust for the Fiskenaesset Anorthosite Complex. 45 refs., 3 figs., 2 tabs.

  19. Adsorption of HO(x) on aerosol surfaces - Implications for the atmosphere of Mars

    NASA Technical Reports Server (NTRS)

    Anbar, A. D.; Leu, M.-T.; Nair, H. A.; Yung, Y. L.

    1993-01-01

    The potential impact of heterogeneous chemistry on the abundance and distribution of HO(x) in the Martian atmosphere is investigated using observational data on dust and ice aerosol distributions combined with an updated photochemical model. Critical parameters include the altitude distributions of aerosols and the surface loss coefficients of HO2 on dust and ice in the lower atmosphere and of H on ice above 40 km. Results of calculations indicate that adsorption of HO2 on dust, or ice near 30 km, can deplete OH abundances in the lower atmosphere by 10 percent or more and that the adsorption of H on ice at 50 km can result in even larger OH depletions (this effect is localized to altitudes greater than 40 km, where CO oxidation is relatively unimportant).

  20. The Asian Tsunami in Sri Lanka: A Personal Experience

    NASA Astrophysics Data System (ADS)

    Chapman, Chris

    2005-01-01

    AGU Fellow Chris Chapman experienced the devastating Asian tsunami firsthand in Sri Lanka. The following is his account, written in the immediate aftermath of the disaster; the footnotes were added later. Chapman is a scientific advisor at Schlumberger Cambridge Research and a specialist in theoretical seismology. At 9:30 A.M. local time (0330 GMT) on Boxing Day, 26 December, my wife, Lillian, and I were eating breakfast at the beachside Triton Hotel1 in Ahungalla, Sri Lanka (about 30 km north of Galle). The previous week we had toured Sri Lanka, ending our trip traveling through Yala National Park and Galle. These were places we hardly knew of before, but now images of them are indelibly imprinted on the world. Of about 150 staying at the Yala Safari Game Lodge, only 11 survived. The center of Galle, a UNESCO World Heritage Site, a sixteenth- to seventeenth-century Portuguese/Dutchfort and port, is essentially gone.

  1. Lagrangian observations of surface coastal flows North of 30∘S in the Humboldt Current system

    NASA Astrophysics Data System (ADS)

    Marín, Víctor H.; Delgado, Luisa E.

    2007-03-01

    We analyze the surface circulation of the coastal waters of the Humboldt Current system based on five Lagrangian satellite-tracked drifters (three launched on January 2005 and two on January 2006) deployed at 30∘S, lasting 30 and 60 days, respectively. Based on the concurrent analysis of buoy's records, sea surface temperature (SST) satellite images and local wind forcing, we propose that the coastal surface circulation between 30∘S and 23∘S can be described as a 0.2ms-1 equatorward flow. Coastal export seems to depend upon the generation of cold-water, locally forced, squirts advecting upwelling waters up to 295 km offshore. Within the nearshore zone ( <30km from the coast), near-inertial motion and alongshore changes in current direction may serve as mechanisms for enhancing water residence time.

  2. Density Structure of the SGR B2 Molecular Cloud Probed by Low-J Lines of CS

    NASA Astrophysics Data System (ADS)

    Minh, Y. C.; Hjalmarson, Å.

    1999-01-01

    We have observed the CS (2-1) and (3-2), and 13CS (2-1) transitions toward the Galactic Center molecular cloud Sgr B2 which consists of several clumps with different chemical properties. We have newly identified a cloud at 30 km s-1 from a CS (2-1) optical depth map. This cloud lies 1.5' South from the Sgr B2 (M) position and has a diameter of ~2.5 pc and a total column density of 7 × 1023 cm-2 assuming optically thin emission of the 13CS (2-1) line. Towards the 2'N Cloud no evidence for a density enhancement is found, which suggests that the strong emission from HNCO and HCO+2 is due to chemical effects. The main isotopic CS lines show broad wing components similar to previous studies, but we find rotational temperatures Trot(CS) < 10 K at this region

  3. Climatology of the relationship between ozone lamina number and daily value of total ozone

    NASA Astrophysics Data System (ADS)

    Krizan, Peter

    2016-04-01

    This poster deals with relationship between positive and negative lamina number and daily values of total ozone at the ozonosonde stations with sufficient length of observations. We search for this relationship at the European and the Japanese ozonosonde stations as well at the American and Canadian midlatitude stations and at the stations in the high latitudes At the European midlatitude stations there is a strong positive correlations between daily values of positive lamina number and daily values of ozone amount up to 30 km. These correlations are weaker and negative for negative lamina number. Are these findings geographically dependent? Is any latitudinal dependence of this relationship? Are there any differences between the Arctic and the Antarctica? This poster try to answer these question.

  4. Climate change and atmospheric chemistry: how will the stratospheric ozone layer develop?

    PubMed

    Dameris, Martin

    2010-10-25

    The discovery of the ozone hole over Antarctica in 1985 was a surprise for science. For a few years the reasons of the ozone hole was speculated about. Soon it was obvious that predominant meteorological conditions led to a specific situation developing in this part of the atmosphere: Very low temperatures initiate chemical processes that at the end cause extreme ozone depletion at altitudes of between about 15 and 30 km. So-called polar stratospheric clouds play a key role. Such clouds develop at temperatures below about 195 K. Heterogeneous chemical reactions on cloud particles initiate the destruction of ozone molecules. The future evolution of the ozone layer will not only depend on the further development of concentrations of ozone-depleting substances, but also significantly on climate change. PMID:20922727

  5. Hydraulic fracturing and the Crooked Lake Sequences: Insights gleaned from regional seismic networks

    NASA Astrophysics Data System (ADS)

    Schultz, Ryan; Stern, Virginia; Novakovic, Mark; Atkinson, Gail; Gu, Yu Jeffrey

    2015-04-01

    Within central Alberta, Canada, a new sequence of earthquakes has been recognized as of 1 December 2013 in a region of previous seismic quiescence near Crooked Lake, ~30 km west of the town of Fox Creek. We utilize a cross-correlation detection algorithm to detect more than 160 events to the end of 2014, which is temporally distinguished into five subsequences. This observation is corroborated by the uniqueness of waveforms clustered by subsequence. The Crooked Lake Sequences have come under scrutiny due to its strong temporal correlation (>99.99%) to the timing of hydraulic fracturing operations in the Duvernay Formation. We assert that individual subsequences are related to fracturing stimulation and, despite adverse initial station geometry, double-difference techniques allow us to spatially relate each cluster back to a unique horizontal well. Overall, we find that seismicity in the Crooked Lake Sequences is consistent with first-order observations of hydraulic fracturing induced seismicity.

  6. Research on the lunar ionosphere using dual-frequency radio occultation with a small VLBI antenna

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Wang, Na; Ping, Jinsong

    2015-04-01

    The Vstar in the Japanese lunar SELENE Radio Science experiment was occulted by virtue of the lunar ionosphere. Using the single sub-satellite and the S/X band coherent radio waves, dual-frequency measurements were acquired at a ground receiving station. In order to investigate the variation of ionospheric total electron content (TEC) surrounding the moon, the TEC, including the terrestrial ionosphere, the interplanetary plasma and lunar ionosphere, can be derived from the phase information of the observational data. We update the observation equation and algorithms, calculate the linear fitting trend of the lunar ionosphere from 60 to 30 km above the surface of the moon. The fitting trend is extended from 30 to 0 km above the surface of the moon. The lunar ionosphere is obtained by using the short time trend extrapolation method.

  7. Reclaiming Our Lives in the Wake of a Nuclear Plant Accident.

    PubMed

    Ando, R

    2016-04-01

    Ryoko Ando lives and works in Iwaki-shi, which is located in the coastal area of Fukushima Prefecture. On 11 March 2011, Iwaki was hit by the Great East Japan Earthquake and tsunami. Then the nuclear plant accident at Fukushima No. 1 nuclear power plant, also located in the coastal area of Fukushima Prefecture, added to the woes of Iwaki residents. Although Iwaki-shi is outside of the ‘restricted area’ set up by the government in the 20 km radius around the nuclear power plant, some municipalities in Iwaki-shi lie within the 30 km radius zone. The residents of Iwaki were naturally concerned about the effects of radioactive contamination. On top of these, they had to confront a wide range of issues, including confusion and miscommunication, reputation risk and infrastructural constraints due to the influx of residents from the ‘restricted area’. PMID:27386587

  8. Concentration of caesium-137, cobalt-60 and potassium-40 in some wild and edible plants around the nuclear power plant in Bulgaria.

    PubMed

    Djingova, R; Kuleff, I

    2002-01-01

    The activities of 137Cs, 60Co and 40K were determined in samples of wild (Taraxacum officinale, Plantago lanceolata and Populus nigra 'Italica') and edible (vegetable, corn, fruit) plants as well as soil collected from the 30 km safety zone of the Bulgarian NPP "Kozloduy" and comparisons with earlier measurements and analyses of samples from other regions and with literature values were performed. The derived transfer factors for 137Cs and 40K from soil to plants ranged between 0.002 and 0.009 for 137Cs, and between 0.09 and 0.35 for 40K. The individual effective dose (calculated from the present results and data on the activity of other foodstuffs and from information about dietary habits) comprises 4.5% of the annual dose limit. PMID:11848152

  9. Intercomparison of remote measurements of stratospheric NO and NO2

    NASA Astrophysics Data System (ADS)

    Roscoe, H. K.; Kerridge, B. J.; Pollitt, S.; Louisnard, N.; Flaud, J. M.

    1990-02-01

    During the 1982 and 1983 Balloon Intercomparison Campaigns, the vertical profile of stratospheric NO2 was measured remotely by nine instruments and that of NO by two. Total overhead columns were measured by two more instruments. Between 30 and 35 km, where measurements overlapped, agreement between NO profiles was within + or - 30 percent, which is better than the accuracies claimed by the experimenters. Between 35 and 40 km, there was similarly good agreement between NO2 profiles, but below 30 km, differences of greater than a factor of 3 were found. In the second campaign, NO2 values from most instruments agreed within their quoted errors, except that the Oxford radiometer gave much lower values; the first campaign and the column measurements show a more uniform spread of results.

  10. Long-term increase in Karenia brevis abundance along the Southwest Florida Coast.

    PubMed

    Brand, Larry E; Compton, Angela

    2007-01-01

    Data collected along the southwest coast of Florida between Tampa Bay and Sanibel Island on the abundance of the toxic dinoflagellate Karenia brevis from 1954 to 2002 were examined for spatial and temporal patterns. K. brevis was found to be approximately 20-fold more abundant within 5 km of the shoreline than 20-30 km offshore. Overall, K. brevis was approximately 13-18-fold more abundant in 1994-2002 than in 1954-1963. In 1954-1963, K. brevis occurred primarily in the fall months. In 1994-2002, it was more abundant not only in the fall, but also in the winter and spring months. It is hypothesized that greater nutrient availability in the ecosystem is the most likely cause of this increase in K. brevis biomass, and the large increase in the human population and its activities in South Florida over the past half century is a major factor. PMID:18437245

  11. Physics of sub-micron cosmic dust particles

    NASA Technical Reports Server (NTRS)

    Roy, N. L.

    1974-01-01

    Laboratory tests with simulated micrometeoroids to measure the heat transfer coefficient are discussed. Equations for ablation path length for electrically accelerated micrometeoroids entering a gas target are developed which yield guidelines for the laboratory measurement of the heat transfer coefficient. Test results are presented for lanthanum hexaboride (LaB sub 6) microparticles in air, argon, and oxygen targets. The tests indicate the heat transfer coefficient has a value of approximately 0.9 at 30 km/sec, and that it increases to approximately unity at 50 km/sec and above. Test results extend to over 100 km/sec. Results are also given for two types of small particle detectors. A solid state capacitor type detector was tested from 0.61 km/sec to 50 km/sec. An impact ionization type detector was tested from 1.0 to 150 km/sec using LaB sub 6 microparticles.

  12. L-Band Radiometer Experiment in the SMOS Test Site Upper Danube

    NASA Astrophysics Data System (ADS)

    Schlenz, Florian; Gebhardt, Timo; Loew, Alexander; Marzahn, Philip; Mauser, Wolfram

    2010-12-01

    In the frame of calibration and validation activities for ESA's soil moisture and ocean salinity mission, SMOS, the University of Munich operates a ground based L-band radiometer (ELBARA II) at 1.4 GHz to test and validate the radiative transfer model L-MEB also used in the SMOS Level 2 processor. The radiometer is situated on a test site near Puch, about 30 km west of Munich in the Upper Danube watershed in southern Germany in a temperate agricultural area. It is mounted on a scaffolding that allows to rotate the antenna which enables it to look at 2 different fields with grass and winter rape as land use respectively. In addition to the radiometer, a variety of complementary sensors are installed measuring all important meteorological and hydrological parameters. First datasets of the radiometer experiment are presented.

  13. Science requirements and feasibility/design studies of a very-high-altitude aircraft for atmospheric research

    NASA Technical Reports Server (NTRS)

    Russell, Philip B.; Lux, David P.; Reed, R. Dale; Loewenstein, Max; Wegener, Steven

    1991-01-01

    The advantages and shortcomings of currently available aircraft for use in very high altitude missions to study such problems as polar ozone or stratosphere-troposphere exchange pose the question of whether to develop advanced aircraft for atmospheric research. To answer this question, NASA conducted a workshop to determine science needs and feasibility/design studies to assess whether and how those needs could be met. It was determined that there was a need for an aircraft that could cruise at an altitude of 30 km with a range of 6,000 miles with vertical profiling down to 10 km and back at remote points and carry a payload of 3,000 lbs.

  14. GPR Application for Road Management System in Slovakia

    NASA Astrophysics Data System (ADS)

    Pitonak, Martin; Filipovsky, Jan

    2015-04-01

    Road Management System in Slovakia was established in 1996. Data for database are collected from Falling Weight Deflectometer, Skiddometer and Profilograph from 25 separated sections with average length of 30 km on yearly basis. The focus is especially on roads that have been built before the year 1996. In September 2014 the Slovak Road Administration announced the new project task which involved additional data request such as structure thicknesses, application to determine the thicknesses of bound layers and base layers, rutting analysis, transverse and longitudinal roughness and cross fall, ditch depths, the road width and pavement width. The request for data processing included the interpretation of the data in graphical display. The requested delivery of the final project data was in December 2014. The presentation summarizes the experiences and results of the data collection methods and technologies, data processing and evaluation methods and finally presenting the results. Also key new finding will be presented.

  15. Archaeological Evidence for a Former Bay at Seaside, Oregon

    NASA Astrophysics Data System (ADS)

    Connolly, Thomas J.

    1995-05-01

    Cultural shell middens, a common feature of coastal landscapes, preserve a record of past human use of coastal resources and often provide important paleoenvironmental information. Molluscan remains from two shell midden sites, located 0.7 km from the modern Pacific coast at Seaside, Oregon, suggest the former presence of a small sheltered bay at this locality. The modern sand beaches in the Seaside area, stretching for 30 km southward from the mouth of the Columbia River, are exposed to high-energy surf where razor clams ( Siliqua patula) are today the only common bivalve. By contrast, over 90% of molluscan remains (by weight) recovered from the archaeological sites represent species that favor sheltered water. Geologic studies in the Seaside area have shown that the beach prograded some 2 km over the last 4 millennia. The midden evidence suggests that the progradation was accompanied by the infilling of a former bay.

  16. Experimental quantification of P-T conditions of mantle refertilisation at shallow depth under spreading ridges and formation of plagioclase + spinel lherzolite

    NASA Astrophysics Data System (ADS)

    Chalot-Prat, Françoise; Falloon, Trevor J.; Green, David H.

    2014-05-01

    We studied the first-order melting process of differentiation in the Earth, and the major process of rejuvenation of the upper mantle after melting related to plate spreading (Chalot-Prat et al, 2010; 2013). We conducted experiments at High Pressure (0.75 and 0.5 GPa) and High Temperature (1260-1100°C) to obtain magma compositions in equilibrium with the mineral assemblages of a plagioclase + spinel lherzolite. These PT conditions prevail at 17-30km below axial oceanic spreading ridges. We used a "trial and error" approach in a system involving nine elements (Cr-Na-Fe-Ca-Mg-Al-Si-Ti-Ni). This approaches as closely as possible a natural mantle composition, Cr being a key element in the system. Our objectives were : • to determine experimentally the compositions of melts in equilibrium with plagioclase + spinel lherzolite, with emphasis on the role of plagioclase composition in controlling melt compositions; • to test the hypothesis that MORB are produced at shallow depth (17-30kms) • to quantify liquid- and mantle residue compositional paths at decreasing T and low P to understand magma differentiation by "percolation-reaction" at shallow depth in the mantle; • to compare experimental mantle mineral compositions to those of re-fertilised oceanic mantle lithosphere outcropping at the axis of oceanic spreading ridges, enabling quantification of the pressure (i.e. depth) and temperature of the re-fertilisation process that leads to formation of plagioclase and indicates the minimum thickness of the lithosphere at ridge axes. In the normative basalt tetrahedron, liquids plot on two parallel cotectic lines from silica-oversaturated (basaltic andesite at 0.75 GPa or andesite at 0.5 GPa) at the calcic end to silica-undersaturated compositions (trachyte) at the sodic end. The lower the pressure, the greater the silica oversaturation. Besides the plagioclase solid solution has a dominant role in determining the solidus temperature of plagioclase + spinel lherzolites

  17. Observations on the geology and geohydrology of the Chernobyl' nuclear accident site, Ukraine

    USGS Publications Warehouse

    Matzko, J.R.; Percious, D.J.; Rachlin, J.; Marples, D.R.

    1994-01-01

    The most highly contaminated surface areas from cesium-137 fallout from the April 1986 accident at the Chernobyl' nuclear power station in Ukraine occur within the 30-km radius evacuation zone set up around the station, and an 80-km lobe extending to the west-southwest. Lower levels of contamination extend 300 km to the west of the power station. The geology, the presence of surface water, a shallow water table, and leaky aquifers at depth make this an unfavorable environment for the long-term containment and storage of the radioactive debris. An understanding of the general geology and hydrology of the area is important to assess the environmental impact of this unintended waste storage site, and to evaluate the potential for radionuclide migration through the soil and rock and into subsurface aquifers and nearby rivers. -from Authors

  18. Quaternary tectonics and basin history of Pahrump and Stewart Valleys, Nevada and California. [Yucca Mountain Project

    SciTech Connect

    Hoffard, J.L. )

    1991-05-01

    The Pahrump fault system is an active fault system located in Pahrump and Stewart Valleys, Nevada and California, in the southern part of the Basin and Range Province. This system is 50 km long by 30 km wide and is comprised of three fault zones: the right-lateral East Nopah fault zone, the right-oblique Pahrump Valley fault zone, and the normal West Spring Mountains fault zone. All three zones have geomorphic evidence for late Quaternary activity. Analysis of active fault patterns and seismic reflection lines suggests that the Pahrump basin has had a two-stage genesis, an early history associated with a period of low angle detachment faulting probably active 10-15 Ma, and a more recent history related to the present dextral shear system, probably active post-4 Ma.

  19. Quaternary tectonics and basin history of Pahrump and Stewart Valleys, Nevada and California

    SciTech Connect

    Hoffard, J.L.

    1991-05-01

    The Pahrump fault system is an active fault system located in Pahrump and Stewart Valleys, Nevada and California, in the southern part of the Basin and Range Province. This system is 50 km long by 30 km wide and is comprised of three fault zones: the right-lateral East Nopah fault zone, the right-oblique Pahrump Valley fault zone, and the normal West Spring Mountains fault zone. All three zones have geomorphic evidence for late Quaternary activity. Analysis of active fault patterns and seismic reflection lines suggests that the Pahrump basin has had a two-stage genesis, an early history associated with a period of low angle detachment faulting probably active 10-15 Ma, and a more recent history related to the present dextral shear system, probably active post-4 Ma.

  20. Analysis of the seismicity in the region of Mirovo salt mine after 8 years monitoring

    NASA Astrophysics Data System (ADS)

    Dimitrova, Liliya; Solakov, Dimcho; Simeonova, Stela; Aleksandrova, Irena; Georgieva, Gergana

    2015-04-01

    Mirovo salt deposit is situated in the NE part of Bulgaria and 5 kilometers away from the town of Provadiya. The mine is in operation since 1956. The salt is produced by dilution and extraction of the brine to the surface. A system of chambers-pillars is formed within the salt body as a result of the applied technology. The mine is situated in a seismically quiet part of the state. The region is characterized with complex geological structure and several faults. During the last 3 decades a large number of small and moderate earthquakes (M<4.5) are realized in the close vicinity of the salt deposit. Local seismological network (LSN) is deployed in the region to monitor the local seismicity. It consists of 6 three component digital stations. A real-time data transfer from LSN stations to National Data Center (in Sofia) is implemented using the VPN and MAN networks of the Bulgarian Telecommunication Company. Common processing and interpretation of the data from LSN and the national seismic network is performed. Real-time and interactive data processing are performed by the Seismic Network Data Processor (SNDP) software package. More than 700 earthquakes are registered by the LSN within 30km region around the mine during the 8 years monitoring. First we processed the data and compile a catalogue of the earthquakes occur within the studied region (30km around the salt mine). Spatial pattern of seismicity is analyzed. A large number of the seismic events occurred within the northern and north-western part of the salt body. Several earthquakes occurred in close vicinity of the mine. Concerning that the earthquakes could be tectonic and/or induced an attempt is made to find criteria to distinguish natural from induced seismicity. To characterize and distinguish the main processes active in the area we also made waveform and spectral analysis of a number of earthquakes.

  1. Integral Field Unit Observations of NGC 4302: Kinematics of the Diffuse Ionized Gas Halo

    NASA Astrophysics Data System (ADS)

    Heald, George H.; Rand, Richard J.; Benjamin, Robert A.; Bershady, Matthew A.

    2007-07-01

    We present moderate-resolution spectroscopy of extraplanar diffuse ionized gas (EDIG) emission in the edge-on spiral galaxy NGC 4302. The spectra were obtained with the SparsePak integral field unit (IFU) at the WIYN Observatory. The wavelength coverage of the observations includes the [N II] λ6548, 6583, Hα, and [S II] λ6716, 6731 emission lines. The spatial coverage of the IFU includes the entirety of the EDIG emission noted in previous imaging studies of this galaxy. The spectra are used to construct position-velocity (PV) diagrams at several ranges of heights above the midplane. Azimuthal velocities are directly extracted from the PV diagrams using the envelope-tracing method and indicate an extremely steep drop-off in rotational velocity with increasing height, with magnitude ~30 km s-1 kpc-1. We find evidence for a radial variation in the velocity gradient on the receding side. We have also performed artificial observations of galaxy models in an attempt to match the PV diagrams. The results of a statistical analysis also favor a gradient of ~30 km s-1 kpc-1. We compare these results with an entirely ballistic model of disk-halo flow and find a strong dichotomy between the observed kinematics and those predicted by the model. The disagreement is worse than we have found for other galaxies in previous studies. The conclusions of this paper are compared to results for two other galaxies, NGC 5775 and NGC 891. We find that the vertical gradient in rotation speed, per unit EDIG scale height, for all three galaxies is consistent with a constant magnitude (within the errors) of approximately 15-25 km s-1 per scale height, independent of radius. This relationship is also true within the galaxy NGC 4302. We also discuss how the gradient depends on the distribution and morphology of the EDIG and the star formation rates of the galaxies, and consequences for the origin of the gas.

  2. At the tip of a propagating rift - The offshore East African Rift

    NASA Astrophysics Data System (ADS)

    Franke, Dieter; Jokat, Wilfried; Ladage, Stefan; Stollhofen, Harald; Klimke, Jennifer; Lutz, Ruediger; Mahanjane, Stefane; Ehrhardt, Axel; Schreckenberger, Bernd

    2016-04-01

    Numerous studies have addressed various aspects of the East African Rift system (EARS) but surprisingly few the offshore continuation of the south-eastern branch of the rift into the Mozambique Channel. Here, we present new evidence for neotectonic deformation derived from modern seismic reflection data and supported by additional geophysical data. The Kerimbas Graben offshore northern Mozambique is the most prominent manifestation of sub-recent extensional deformation. The seismic reflection data reveals that recent normal faulting often utilizes preexisting, deeply buried half-graben structures which likely are related to the formation of the Somali Basin. The ~30 km wide and ~150 km long symmetric graben is in a stage where the linkage of scattered normal faults already did happen, resulting in increased displacement and accommodation of most of the extension across the basin. However, deep earthquakes below the rift indicate a strong and still preserved lithospheric mantle. Extension is becoming diffuse where an onshore suture, subdividing the northern from the southern metamorphic basement onshore Mozambique, is closest to the offshore rift. It appears likely that this suture is the origin for the variation in rifting style, indicating that mantle fabric resulting from a Cambrian collision has been preserved as mechanical anisotropy of the lithospheric mantle. Further south the rift focuses in an about 30 km wide half-graben. An important finding is that the entire offshore branch of the EARS lacks significant volcanism. Along the offshore EARS there are only negligible indications for recent volcanism in the reflection seismic data such as sills and dikes. Apparently the "Comoros mantle plume" (French and Romanowicz, 2015) has a very minor influence on the progressive extensional deformation along the northern Mozambique continental margin, leading eventually to breakup sometimes in the future. Combining structural with earthquake data reveals that the magma

  3. Paleo-elevation and subsidence of ˜145Ma Shatsky Rise inferred from CO2 and H2O in fresh volcanic glass

    NASA Astrophysics Data System (ADS)

    Shimizu, Kenji; Shimizu, Nobumichi; Sano, Takashi; Matsubara, Noritaka; Sager, William

    2013-12-01

    Shatsky Rise, a large Mesozoic oceanic plateau in the northwest Pacific, consists of three massifs (Tamu, Ori, and Shirshov) that formed near a mid-ocean-ridge triple junction. Published depth estimates imply that Shatsky Rise has not subsided normally, like typical oceanic lithosphere. We estimated paleo-eruption depths of Shatsky Rise massifs on the basis of dissolved CO2 and H2O in volcanic glass and descriptions of cores recovered from five sites of Integrated Ocean Drilling Program Expedition 324. Initial maximum elevations of Shatsky Rise are estimated to be 2500-3500 m above the surrounding seafloor and the ensuing subsidence of Shatsky Rise is estimated to be 2600-3400 m. We did not observe the anomalously low subsidence that has been reported for both Shatsky Rise and the Ontong Java Plateau. Although we could not resolve whether Shatsky Rise originated from a hot mantle plume or non-plume fusible mantle, uplift and subsidence histories of Shatsky Rise for the both cases are constrained based on the subsidence trend from the center of Tamu Massif (˜2600 m) toward the flank of Ori Massif (˜3400 m). In the case of a hot mantle plume origin, Shatsky Rise may have formed on young (˜5 Ma) pre-existing oceanic crust with a total crustal thickness of ˜20 km. For this scenario, the center of Shatsky Rise is subsequently uplifted by later (prolonged) crustal growth, forming the observed ˜30 km thickness crust. For a non-plume origin, Shatsky Rise may have formed at the spreading ridge center as initially thick crust (˜30 km thickness), with later reduced subsidence caused by the emplacement of a buoyant mass-perhaps a refractory mantle residuum-beneath the center of Shatsky Rise.

  4. Source model and ground shaking of the 2015 Gorkha, Nepal Mw7.8 earthquake

    NASA Astrophysics Data System (ADS)

    Wei, S.; Wang, T.; Lindsey, E. O.; Avouac, J. P.; Graves, R. W.; Hubbard, J.; Hill, E.; Barbot, S.; Tapponnier, P.; Karakas, C.; Helmberger, D. V.

    2015-12-01

    The 2015 Mw7.8 Gorkha, Nepal earthquake ruptured a previously locked portion of the Main Himalayan Thrust fault (MHT) that has not slipped in a large event since 1833 (Mw7.6). The earthquake was well recorded by geodetic (SAR, InSAR and GPS) and seismic instruments. In particular, high-rate (5Hz) GPS channels provide waveform records at local distances, with three stations located directly above the major asperities of the earthquake. Here we derive a kinematic rupture model of the earthquake by jointly inverting the seismic and geodetic data, using a Kostrov source time function with variable rise times. Our inversion result indicates that the earthquake had a weak initiation and ruptured unilaterally along strike towards the ESE, with an average rupture speed of 3.0km/s and total duration of ~60s. The preferred slip rate of the beginning portion of the rupture had a longer rise time compared with the strongest ruptures, which took place at ~22s and ~35s after the origin, located 30km to the northwest and 20km to the east of the Kathmandu valley, respectively. The horizontal vibration and amplification of ground shaking in the valley was well recorded by one of the GPS stations (NAST) and the accelerometric station (KANTP), with a dominant frequency of 0.25Hz. A simplified basin model with top shear wave speed of 250 m/s and geometry constrained by a previous micro-tremor study can largely explain the amplification and vibration, realized by 3D staggered-grid finite difference simulations. This study shows that ground shaking can be strongly affected by complexities of the rupture and velocity structure.

  5. Paleoseismicity of two historically quiescent faults in Australia: Implications for fault behavior in stable continental regions

    USGS Publications Warehouse

    Crone, A.J.; De Martini, P. M.; Machette, M.M.; Okumura, K.; Prescott, J.R.

    2003-01-01

    Paleoseismic studies of two historically aseismic Quaternary faults in Australia confirm that cratonic faults in stable continental regions (SCR) typically have a long-term behavior characterized by episodes of activity separated by quiescent intervals of at least 10,000 and commonly 100,000 years or more. Studies of the approximately 30-km-long Roopena fault in South Australia and the approximately 30-km-long Hyden fault in Western Australia document multiple Quaternary surface-faulting events that are unevenly spaced in time. The episodic clustering of events on cratonic SCR faults may be related to temporal fluctuations of fault-zone fluid pore pressures in a volume of strained crust. The long-term slip rate on cratonic SCR faults is extremely low, so the geomorphic expression of many cratonic SCR faults is subtle, and scarps may be difficult to detect because they are poorly preserved. Both the Roopena and Hyden faults are in areas of limited or no significant seismicity; these and other faults that we have studied indicate that many potentially hazardous SCR faults cannot be recognized solely on the basis of instrumental data or historical earthquakes. Although cratonic SCR faults may appear to be nonhazardous because they have been historically aseismic, those that are favorably oriented for movement in the current stress field can and have produced unexpected damaging earthquakes. Paleoseismic studies of modern and prehistoric SCR faulting events provide the basis for understanding of the long-term behavior of these faults and ultimately contribute to better seismic-hazard assessments.

  6. Incorporating Sentinel-2-like remote sensing products in the hydrometeorological modelling over an agricultural area in south west France

    NASA Astrophysics Data System (ADS)

    Rivalland, Vincent; Gascoin, Simon; Etchanchu, Jordi; Coustau, Mathieu; Cros, Jérôme; Tallec, Tiphaine

    2016-04-01

    The Sentinel-2 mission will enable to monitor the land cover and the vegetation phenology at high-resolution (HR) every 5 days. However, current Land Surface Models (LSM) typically use land cover and vegetation parameters derived from previous low to mid resolution satellite missions. Here we studied the effect of introducing Sentinel-2-like data in the simulation of the land surface energy and water fluxes in a region dominated by cropland. Simulations were performed with the ISBA-SURFEX LSM, which is used in the operational hydrometeorological chain of Meteo-France for hydrological forecasts and drought monitoring. By default, SURFEX vegetation land surface parameters and temporal evolution are from the ECOCLIMAP II European database mostly derived from MODIS products at 1 km resolution. The model was applied to an experimental area of 30 km by 30 km in south west France. In this area the resolution of ECOCLIMAP is coarser than the typical size of a crop field. This means that several crop types can be mixed in a pixel. In addition ECOCLIMAP provides a climatology of the vegetation phenology and thus does not account for the interannual effects of the climate and land management on the crop growth. In this work, we used a series of 26 Formosat-2 images at 8-m resolution acquired in 2006. From this dataset, we derived a land cover map and a leaf area index map (LAI) at each date, which were substituted to the ECOCLIMAP land cover map and the LAI maps. The model output water and energy fluxes were compared to a standard simulation using ECOCLIMAP only and to in situ measurements of soil moisture, latent and sensible heat fluxes. The results show that the introduction of the HR products improved the timing of the evapotranspiration. The impact was the most visible on the crops having a growing season in summer (maize, sunflower), because the growth period is more sensitive to the climate.

  7. Seismic velocity models for the Denali fault zone along the Richardson Highway, Alaska

    USGS Publications Warehouse

    Brocher, T.M.; Fuis, G.S.; Lutter, W.J.; Christensen, N.I.; Ratchkovski, N.A.

    2004-01-01

    Crustal-scale seismic-velocity models across the Denali fault zone along the Richardson Highway show a 50-km-thick crust, a near vertical fault trace, and a 5-km-wide damage zone associated with the fault near Trans-Alaska Pipeline Pump Station 10, which provided the closest strong ground motion recordings of the 2002 Denali fault earthquake. We compare models, derived from seismic reflection and refraction surveys acquired in 1986 and 1987, to laboratory measurements of seismic velocities for typical metamorphic rocks exposed along the profiles. Our model for the 1986 seismic reflection profile indicates a 5-km-wide low-velocity zone in the upper 1 km of the Denali fault zone, which we interpret as fault gouge. Deeper refractions from our 1987 line image a 40-km wide, 5-km-deep low-velocity zone along the Denali fault and nearby associated fault strands, which we attribute to a composite damage zone along several strands of the Denali fault zone and to the obliquity of the seismic line to the fault zone. Our velocity model and other geophysical data indicate a nearly vertical Denali fault zone to a depth of 30 km. After-shocks of the 2002 Denali fault earthquake and our velocity model provide evidence for a flower structure along the fault zone consisting of faults dipping toward and truncated by the Denali fault. Wide-angle reflections indicate that the crustal thickness beneath the Denali fault is transitional between the 60-km-thick crust beneath the Alaska Range to the south, and the extended, 30-km-thick crust of the Yukon-Tanana terrane to the north.

  8. Disentangling the drivers of metacommunity structure across spatial scales

    PubMed Central

    Meynard, Christine N.; Lavergne, Sébastien; Boulangeat, Isabelle; Garraud, Luc; Van Es, Jérémie; Mouquet, Nicolas; Thuiller, Wilfried

    2014-01-01

    Aim Metacommunity theories attribute different relative degrees of importance to dispersal, environmental filtering, biotic interactions and stochastic processes in community assembly, but the role of spatial scale remains uncertain. Here we used two complementary statistical tools to test: (1) whether or not the patterns of community structure and environmental influences are consistent across resolutions; and (2) whether and how the joint use of two fundamentally different statistical approaches provides a complementary interpretation of results. Location Grassland plants in the French Alps. Methods We used two approaches across five spatial resolutions (ranging from 1 km × 1 km to 30 km × 30 km): variance partitioning, and analysis of metacommunity structure on the site-by-species incidence matrices. Both methods allow the testing of expected patterns resulting from environmental filtering, but variance partitioning allows the role of dispersal and environmental gradients to be studied, while analysis of the site-by-species metacommunity structure informs an understanding of how environmental filtering occurs and whether or not patterns differ from chance expectation. We also used spatial regressions on species richness to identify relevant environmental factors at each scale and to link results from the two approaches. Results Major environmental drivers of richness included growing degree-days, temperature, moisture and spatial or temporal heterogeneity. Variance partitioning pointed to an increase in the role of dispersal at coarser resolutions, while metacommunity structure analysis pointed to environmental filtering having an important role at all resolutions through a Clementsian assembly process (i.e. groups of species having similar range boundaries and co-occurring in similar environments). Main conclusions The combination of methods used here allows a better understanding of the forces structuring ecological communities than either one of them used

  9. Style and magnitude of Mesozoic thrust faulting in the hinterland of the Sevier thrust belt Pequop Mountains-Wood Hills-East Humboldt Range region, northeast Nevada

    SciTech Connect

    Camilleri, P.A. . Dept. of Geology and Geophysics)

    1993-04-01

    The Pequop Mountains (PM), Wood Hills (WH) and East Humboldt Range (EHR), NE Nevada, provide evidence that the hinterland of the Sevier thrust belt experienced large-magnitude Mesozoic shortening ([>=]55 km) and crustal thickening ([>=] 30 km). These ranges expose a structurally continuous crustal cross section of unmetamorphosed to high pressure upper amphibolite facies Triassic to Precambrian miogeoclinal strata. This sequence lies structurally beneath unmetamorphosed extensional klippen that omit metamorphic grade and crustal section, but also repeat stratigraphic units. Because they repeat stratigraphic units, the underlying miogeoclinal section, or footwall, must have once lain beneath a thrust fault (herein named the Windermere thrust). The footwall of the Windermere thrust was exhumed by two generations of top-to-the-W-NW low-angle normal faults that are distinguished by whether they are depositionally overlapped by Eocene volcanic rocks or if they cut the volcanic rocks in their hanging walls. The latter phase is associated with development of the mid-Tertiary extensional mylonitic shear zone in the EHR. An integration of geobarometric, metamorphic, and map data suggest (1) a NW dip of the footwall of the Windermere thrust with metamorphic facies belts trending perpendicular to dip direction and metamorphic grade increasing down dip, and (2) a top-to-the-SE sense-of-slip for the Windermere thrust. Assuming that the Windermere thrust comprised a flat on the youngest rocks exposed in the footwall (Triassic), the Mesozoic depth to the Windermere thrust in the northern PM is [>=] 7 km, in WH is [approximately]10--16 km, and in the EHR[>=]30 km. The Windermere thrust accommodated a minimum of 50 km of shortening associated with the Independence thrust is [>=] 5 km. These data indicate that the amount of hinterland shortening in NE Nevada greatly exceeds that to the south in the Eureka belt.

  10. Sensitivity studies of high-resolution RegCM3 simulations of precipitation over the European Alps: the effect of lateral boundary conditions and domain size

    NASA Astrophysics Data System (ADS)

    Nadeem, Imran; Formayer, Herbert

    2015-08-01

    A suite of high-resolution (10 km) simulations were performed with the International Centre for Theoretical Physics (ICTP) Regional Climate Model (RegCM3) to study the effect of various lateral boundary conditions (LBCs), domain size, and intermediate domains on simulated precipitation over the Great Alpine Region. The boundary conditions used were ECMWF ERA-Interim Reanalysis with grid spacing 0.75∘, the ECMWF ERA-40 Reanalysis with grid spacing 1.125 and 2.5∘, and finally the 2.5∘ NCEP/DOE AMIP-II Reanalysis. The model was run in one-way nesting mode with direct nesting of the high-resolution RCM (horizontal grid spacing Δx = 10 km) with driving reanalysis, with one intermediate resolution nest (Δx = 30 km) between high-resolution RCM and reanalysis forcings, and also with two intermediate resolution nests (Δx = 90 km and Δx = 30 km) for simulations forced with LBC of resolution 2.5∘. Additionally, the impact of domain size was investigated. The results of multiple simulations were evaluated using different analysis techniques, e.g., Taylor diagram and a newly defined useful statistical parameter, called Skill-Score, for evaluation of daily precipitation simulated by the model. It has been found that domain size has the major impact on the results, while different resolution and versions of LBCs, e.g., 1.125∘ ERA40 and 0.7∘ ERA-Interim, do not produce significantly different results. It is also noticed that direct nesting with reasonable domain size, seems to be the most adequate method for reproducing precipitation over complex terrain, while introducing intermediate resolution nests seems to deteriorate the results.

  11. A comparison study between model-predicted and OMI-retrieved tropospheric NO 2 columns over the Korean peninsula

    NASA Astrophysics Data System (ADS)

    Han, K. M.; Lee, C. K.; Lee, J.; Kim, J.; Song, C. H.

    2011-06-01

    In this study, Community Multi-scale Air Quality (CMAQ) model simulations, using the INTEX-B (Intercontinental Chemical Transport Experiment-Phase B) emission inventory for North Korea and China, CAPSS (Clean Air Policy Support System) emission inventory for South Korea, and REAS (Regional Emission Inventory in Asia) emission inventory for Japan, were carried out over four seasonal episodes from 2006, with a fine grid resolution of 30 km × 30 km, in order to evaluate the accuracy of the NO x emissions over the Korean peninsula. The tropospheric NO 2 columns from the CMAQ model simulations were then compared with those retrieved from a satellite sensor, Ozone Monitoring Instrument (OMI), over the Korean peninsula as well as briefly over East Asia. The results showed that the CMAQ modeling, using the NO x emissions from the CAPSS inventory over South Korea, produced tropospheric NO 2 columns that were over-predicted by factors between 1.38 and 1.87 compared to the OMI-retrieved tropospheric NO 2 columns. This appears to be in line with the findings from a previous study, i.e. when the ACE-ASIA emission inventory was used for the episodes from 2001 to 2003, the CMAQ modeling tended to produce NO 2 columns that were ˜1.46 times larger than the GOME-derived NO 2 columns over South Korea. On the other hand, over North Korea, the NO x emissions of the INTEX-B emission inventory appear to be overestimated by factors between 1.55 and 7.46 (3.18 over the four seasonal episodes), based on the comparison study between the CMAQ-simulated and OMI-retrieved tropospheric NO 2 columns. This may be caused by the large uncertainty in the NO x emission fluxes from North Korea due to insufficient information on the economic activity and energy consumption related to the political instability in North Korea.

  12. Resolution and Dynamical Core Dependence of Atmospheric River Frequency in Global Model Simulations

    SciTech Connect

    Hagos, Samson M.; Leung, Lai-Yung R.; Yang, Qing; Zhao, Chun; Lu, Jian

    2015-04-01

    This study examines the sensitivity of atmospheric river (AR) frequency simulated by a global model with different grid resolutions and dynamical cores. Analysis is performed on aquaplanet simulations using version 4 of Community Atmosphere Model (CAM4) at 240, 120, 60 and 30 km model resolutions each with the Model for Prediction Across Scales (MPAS) and High-Order Methods Modeling Environment (HOMME) dynamical cores. The frequency of AR events decreases with model resolution and the HOMME dynamical core produces more AR events than MPAS. Comparing the frequencies determined using absolute and percentile thresholds of large-scale conditions used to define an AR, model sensitivity is found to be related to the overall sensitivity of sub-tropical westerlies, atmospheric precipitable water content and profile and to a lesser extent on extra-tropical Rossby wave activity to model resolution and dynamical core. Real world simulations using MPAS at 120 km and 30 km grid resolutions also exhibit a decrease of AR frequency with increasing resolution over southern East Pacific, but there difference is smaller over northern East Pacific. This inter-hemispheric difference is related to the enhancement of convection in over the tropics with increased resolution. This anomalous convection sets off Rossby wave patterns that weaken the subtropical westerlies over southern East Pacific but have relatively little effect on those over northern East Pacific. In comparison to NCEP2 reanalysis, MPAS real world simulations are found to underestimate AR frequencies at both resolutions likely because of their climatologically drier sub-tropics and poleward shifted jets. This study highlights the important links between model climatology of large-scale conditions and extremes.

  13. A new dynamic approach for statistical optimization of GNSS radio occultation bending angles for optimal climate monitoring utility

    NASA Astrophysics Data System (ADS)

    Li, Y.; Kirchengast, G.; Scherllin-Pirscher, B.; Wu, S.; Schwaerz, M.; Fritzer, J.; Zhang, S.; Carter, B. A.; Zhang, K.

    2013-12-01

    Navigation Satellite System (GNSS)-based radio occultation (RO) is a satellite remote sensing technique providing accurate profiles of the Earth's atmosphere for weather and climate applications. Above about 30 km altitude, however, statistical optimization is a critical process for initializing the RO bending angles in order to optimize the climate monitoring utility of the retrieved atmospheric profiles. Here we introduce an advanced dynamic statistical optimization algorithm, which uses bending angles from multiple days of European Centre for Medium-range Weather Forecasts (ECMWF) short-range forecast and analysis fields, together with averaged-observed bending angles, to obtain background profiles and associated error covariance matrices with geographically varying background uncertainty estimates on a daily updated basis. The new algorithm is evaluated against the existing Wegener Center Occultation Processing System version 5.4 (OPSv5.4) algorithm, using several days of simulated MetOp and observed CHAMP and COSMIC data, for January and July conditions. We find the following for the new method's performance compared to OPSv5.4: 1.) it significantly reduces random errors (standard deviations), down to about half their size, and leaves less or about equal residual systematic errors (biases) in the optimized bending angles; 2.) the dynamic (daily) estimate of the background error correlation matrix alone already improves the optimized bending angles; 3.) the subsequently retrieved refractivity profiles and atmospheric (temperature) profiles benefit by improved error characteristics, especially above about 30 km. Based on these encouraging results, we work to employ similar dynamic error covariance estimation also for the observed bending angles and to apply the method to full months and subsequently to entire climate data records.

  14. Stratospheric Semi-Decadal Oscillations in NCEP Data

    NASA Technical Reports Server (NTRS)

    Mayr, H. G.; Mengel, J. G.; Huang, F. T.; Talaat, E. R.; Nash, E. R.; Reddy, C. A.

    2008-01-01

    An analysis of the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) data is presented to provide a more complete description of the stratospheric 5-year semi-decadal (SD) oscillation (Mayr et al., 2007). The zonal-mean temperature and zonal wind data from the Atmospheric Research R-1 analysis are employed, covering the years from 1962 to 2002 in the altitude range from 10 to 30km. For diagnostic purposes, the data are separated into the hemispherically symmetric and anti-symmetric components, and spectral analysis is applied to identify the signatures of the SD oscillations. Through the synthesis or filtering of spectral features, the SD modulations of the annual oscillation (AO) and quasi-biennial oscillation (QBO) are delineated. In agreement with the earlier findings, the magnitude of the SD oscillation is more pronounced when the 30-month QBO dominates during the years from 1975 to 1995. This is consistent with results from a numerical model, which shows that such a QBO generates the SD oscillation through interaction with the 12-month AO. In the zonal winds, the SD oscillation in the NCEP data is confined to equatorial latitudes, where it modulates the symmetric AO and QBO by about 5 m/s below 30 km. In the temperature data, the effect is also seen around the equator, but it is much larger at polar latitudes where the SD oscillation produces variations as large as 2 K. Our data analysis indicates that the SD oscillation is mainly hemispherically symmetric, and it appears to originate at equatorial latitudes where most of the energy resides.

  15. Spatial regression analysis of traffic crashes in Seoul.

    PubMed

    Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-ihn; Ulfarsson, Gudmundur F

    2016-06-01

    Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30 km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30 km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands. PMID:26994374

  16. A Detailed Study of the Structure of the Nested Planetary Nebula, Hb 12, the Matryoshka Nebula

    NASA Astrophysics Data System (ADS)

    Clark, D. M.; López, J. A.; Edwards, M. L.; Winge, C.

    2014-11-01

    We present near-IR, integral field spectroscopic observations of the planetary nebula (PN) Hb 12 using Near-infrared Integral Field Spectrograph (NIFS) on Gemini-North. Combining NIFS with the adaptive optics system Altair, we provide a detailed study of the core and inner structure of this PN. We focus the analysis in the prominent emission lines [Fe II] (1.6436 μm), He I (2.0585 μm), H2 (2.1214 μm), and Brγ (2.16553 μm). We find that the [Fe II] emission traces a tilted system of bipolar lobes, with the northern lobe being redshifted and the southern lobe blueshifted. The [Fe II] emission is very faint at the core and only present close to the systemic velocity. There is no H2 emission in the core, whereas the core is prominent in the He I and Brγ recombination lines. The H2 emission is concentrated in equatorial arcs of emission surrounding the core and expanding at ~30 km s-1. These arcs are compared with Hubble Space Telescope images and shown to represent nested loops belonging to the inner sections of a much larger bipolar structure that replicates the inner one. The He I and Brγ emission from the core clearly show a cylindrical central cavity that seems to represent the inner walls of an equatorial density enhancement or torus. The torus is 0.''2 wide (≡200 AU radius at a distance of 2000 pc) and expanding at <=30 km s-1. The eastern wall of the inner torus is consistently more intense than the western wall, which could indicate the presence of an off-center star, such as is observed in the similar hourglass PN, MyCn 18. A bipolar outflow is also detected in Brγ emerging within 0.''1 from the core at ~ ± 40 km s-1.

  17. Continuous GPS observations of postseismic deformation following the 16 October 1999 Hector Mine, California, earthquake (Mw 7.1)

    USGS Publications Warehouse

    Hudnutt, K.W.; King, N.E.; Galetzka, J.E.; Stark, K.F.; Behr, J.A.; Aspiotes, A.; van, Wyk S.; Moffitt, R.; Dockter, S.; Wyatt, F.

    2002-01-01

    Rapid field deployment of a new type of continuously operating Global Positioning System (GPS) network and data from Southern California Integrated GPS Network (SCIGN) stations that had recently begun operating in the area allow unique observations of the postseismic deformation associated with the 1999 Hector Mine earthquake. Innovative solutions in fieldcraft, devised for the 11 new GPS stations, provide high-quality observations with 1-year time histories on stable monuments at remote sites. We report on our results from processing the postseismic GPS data available from these sites, as well as 8 other SCIGN stations within 80 km of the event (a total of 19 sites). From these data, we analyze the temporal character and spatial pattern of the postseismic transients. Data from some sites display statistically significant time variation in their velocities. Although this is less certain, the spatial pattern of change in the postseismic velocity field also appears to have changed. The pattern now is similar to the pre-Landers (pre-1992) secular field, but laterally shifted and locally at twice the rate. We speculate that a 30 km ?? 50 km portion of crust (near Twentynine Palms), which was moving at nearly the North American plate rate (to within 3.5 mm/yr of that rate) prior to the 1992 Landers sequence, now is moving along with the crust to the west of it, as though it has been entrained in flow along with the Pacific Plate as a result of the Landers and Hector Mine earthquake sequence. The inboard axis of right-lateral shear deformation (at lower crustal to upper mantle depth) may have jumped 30 km farther into the continental crust at this fault junction that comprises the southern end of the eastern California shear zone.

  18. Tectonic Controls on Pyroclastic Volcanism on Mercury

    NASA Astrophysics Data System (ADS)

    Habermann, M.; Klimczak, C.

    2015-12-01

    Over much of Mercury's geologic history the planet has contracted as a response to cooling of its interior. Such contraction is evident as landforms formed by thrust faults, which have accommodated a radius decrease of ~5 km. Stresses from global contraction imposed on the lithosphere are not favorable for and prevent volcanism. Yet, there are examples on Mercury where pyroclastic deposits superpose thrust faults, indicating that explosive volcanism has occurred after the onset of global contraction. To better understand the spatial relationships of thrust faults with the pyroclastic vents, we used MESSENGER image data to categorize 343 vents by their occurrence either (1) within 30 km, (2) within 100 km, or (3) farther than 100 km from a thrust fault, using ArcGIS. Vents were also classified by their association with impact craters. Results show that 75% of all vents are located within impact structures, with 36% of vents within 30 km of thrust faults, 41% located farther than 30 but within 100 km of thrust faults, and 23% of vents are farther than 100 km from a thrust fault. To investigate whether this geospatial relationship is tectonically controlled, three areas —representing the three categories of vents— were mapped, and the locations and orientations of vents and faults were recorded. Stress changes around these faults were then numerically modeled with the COULOMB 3.4 software, using elastic rock properties, a background stress field, and fault size- and dislocation parameters applicable to conditions of Mercury's global contractional tectonic environment. Preliminary results indicate that stress changes can locally produce conditions beneficial for volcanism. Further modeling will determine if such beneficial conditions are geospatially correlated with the pyroclastic vents and thus enable a better understanding of pyroclastic volcanism on Mercury after the onset of global contraction.

  19. MAPPING THE ASYMMETRIC THICK DISK. III. THE KINEMATICS AND INTERACTION WITH THE GALACTIC BAR

    SciTech Connect

    Humphreys, Roberta M.; Grammer, Skyler; Davidson, Kris; Beers, Timothy C.; Lee, Young Sun; Cabanela, Juan E.; Larsen, Jeffrey A. E-mail: grammer@astro.umn.edu E-mail: beers@pa.msu.edu E-mail: cabanela@mnstate.edu

    2011-04-15

    In the first two papers of this series, Larsen et al. describe our faint CCD survey in the inner Galaxy and map the overdensity of thick disk stars in Quadrant 1 (Q1) to 5 kpc or more along the line of sight. The regions showing the strongest excess are above the density contours of the bar in the Galactic disk. In this third paper on the asymmetric thick disk, we report on radial velocities and derived metallicity parameters for over 4000 stars in Q1, above and below the plane, and in Quadrant 4 (Q4) above the plane. We confirm the corresponding kinematic asymmetry first reported by Parker et al., extended to greater distances and with more spatial coverage. The thick disk stars in Q1 have a rotational lag of 60-70 km s{sup -1} relative to circular rotation, and the metal-weak thick disk stars have an even greater lag of 100 km s{sup -1}. Both lag their corresponding populations in Q4 by {approx}30 km s{sup -1}. Interestingly, the disk stars in Q1 also appear to participate in the rotational lag by about 30 km s{sup -1}. The enhanced rotational lag for the thick disk in Q1 extends to 4 kpc or more from the Sun. At 3-4 kpc, our sight lines extend above the density contours on the near side of the bar, and as our lines of sight pass directly over the bar the rotational lag appears to decrease. This is consistent with a 'gravitational wake' induced by the rotating bar in the disk which would trap and pile up stars behind it. We conclude that a dynamical interaction with the stellar bar is the most probable explanation for the observed kinematic and spatial asymmetries.

  20. Modelling trends in tropical column ozone with the UKCA chemistry-climate model

    NASA Astrophysics Data System (ADS)

    Keeble, James; Bednarz, Ewa; Banerjee, Antara; Abraham, Luke; Harris, Neil; Maycock, Amanda; Pyle, John

    2016-04-01

    Trends in tropical column ozone under a number of different emissions scenarios are explored with the UM-UKCA coupled chemistry climate model. A transient 1960-2100 simulation was run following the RCP6 scenario. Tropical averaged (10S-10N) total column ozone values decrease from the 1970s, reaching a minimum around 2000, and return to their 1980 values around 2040, consistent with the use and emission of ozone depleting substances, and their later controls under the Montreal Protocol. However, when the total column is subdivided into three partial columns, extending from the surface to the tropopause, the tropopause to 30km, and 30km to 50km, significant differences to the total column trend are seen. Modelled tropospheric column values increase from 1960-2000 before remaining steady throughout the 21st Century. Lower stratospheric column values decrease rapidly from 1960-2000, remain steady until 2050 before slowly decreasing to 2100, never recovering to their 1980s values. Upper stratospheric values decrease from 1960-2000, before rapidly increasing throughout the 21st Century, recovering to 1980s values by ~2020 and are significantly increased above the 1980s values by 2100. Using a series of idealised model simulations with varying concentrations of greenhouse gases and ozone depleting substances, we assess the physical processes driving the partial column response in the troposphere, lower stratosphere and upper stratosphere, and assess how these processes change under different emissions scenarios. Finally, we present a simple, linearised model for predicting tropical column ozone values based on greenhouse gas and ozone depleting substance scenarios.

  1. Post seismic deformation associated with the 1992 Mω=7.3 Landers earthquake, southern California

    USGS Publications Warehouse

    Savage, J.C.; Svarc, J.L.

    1997-01-01

    Following the 1992 Mω=7.3 Landers earthquake, a linear array of 10 geodetic monuments at roughly 5-km spacing was established across the Emerson fault segment of the Landers rupture. The array trends perpendicular to the local strike of the fault segment and extends about 30 km on either side of it. The array was surveyed by Global Positioning System 0.034, 0.048, 0.381, 1.27, 1.88, 2.60, and 3.42 years after the Landers earthquake to measure both the spatial and temporal character of the postearthquake relaxation. The temporal behavior is described roughly by a short-term (decay time 84±23 days) exponential relaxation superimposed upon an apparently linear trend. Because the linear trend represents motions much more rapid than the observed preseismic motions, we attribute that trend to a slower (decay time greater than 5 years) postseismic relaxation, the curvature of which cannot be resolved in the short run (3.4 years) of postseismic data. About 100 mm of right-lateral displacement and 50 mm of fault-normal displacement accumulated across the geodetic array in the 3.4-year interval covered by the postseismic surveys. Those displacements are attributed to postseismic, right-lateral slip in the depth interval 10 to 30 km on the downward extension of the rupture trace. The right-lateral slip amounted to about 1 m directly beneath the geodetic array, and the fault-normal displacement is apparently primarily a consequence of the curvature of the rupture. These conclusions are based upon dislocation models fit to the observed deformation. However, no dislocation model was found with rms residuals as small as the expected observational error.

  2. Comparison of ozone profiles between Superconducting Submillimeter-Wave Limb-Emission Sounder and worldwide ozonesonde measurements

    NASA Astrophysics Data System (ADS)

    Imai, Koji; Fujiwara, Masatomo; Inai, Yoichi; Manago, Naohiro; Suzuki, Makoto; Sano, Takuki; Mitsuda, Chihiro; Naito, Yoko; Hasebe, Fumio; Koide, Takashi; Shiotani, Masato

    2013-11-01

    compared ozone profiles measured by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) with those taken at worldwide ozonesonde stations. To assess the quality of the SMILES version 2.3 ozone data for 16-30 km, 601 ozonesonde profiles were compared with the coincident SMILES ozone profiles. The agreement between SMILES and ozonesonde measurements was generally good within 5%-7% for 18-30 km at middle and high latitudes but degraded below 18 km. At low latitudes, however, the SMILES ozone data showed larger values (~6%-15% for 20-26 km) than those at middle and high latitudes. To explain this bias, we explored some possible issues in the ozonesonde measurement system. One possibility is due to a pressure bias in radiosonde measurements with a pressure sensor, but it would be within a few percent. We also examined an issue of the ozonesonde's response time. The response time was estimated from ozonesonde measurements with ascending and descending profiles showing clear difference, by using the time lag correction method to minimize the difference between them. Our estimation shows 28 s on average which is a similar value derived by prelaunch preparation. By applying this correction to the original profiles, we found a negative bias of the ascending ozonesonde measurement more than 7% at 20 km in the equatorial latitude where the vertical gradient of ozone is steep. The corrected ozonesonde profiles showed better agreement with the SMILES data. We suggest that the response time of ozonesondes could create a negative bias, particularly in the lower stratosphere at equatorial latitudes.

  3. Spatial modeling of wild bird risk factors to investigate highly pathogenic A(H5N1) avian influenza virus transmission

    USGS Publications Warehouse

    Prosser, Diann J.; Hungerford, Laura L.; Erwin, R. Michael; Ottinger, Mary Ann; Takekawa, John Y.; Newman, Scott H.; Xiao, Xianming; Ellis, Erie C.

    2016-01-01

    One of the longest-persisting avian influenza viruses in history, highly pathogenic avian influenza virus (HPAIV) A(H5N1), continues to evolve after 18 years, advancing the threat of a global pandemic. Wild waterfowl (family Anatidae), are reported as secondary transmitters of HPAIV, and primary reservoirs for low-pathogenic avian influenza viruses, yet spatial inputs for disease risk modeling for this group have been lacking. Using GIS and Monte Carlo simulations, we developed geospatial indices of waterfowl abundance at 1 and 30 km resolutions and for the breeding and wintering seasons for China, the epicenter of H5N1. Two spatial layers were developed: cumulative waterfowl abundance (WAB), a measure of predicted abundance across species, and cumulative abundance weighted by H5N1 prevalence (WPR), whereby abundance for each species was adjusted based on prevalence values then totaled across species. Spatial patterns of the model output differed between seasons, with higher WAB and WPR in the northern and western regions of China for the breeding season and in the southeast for the wintering season. Uncertainty measures indicated highest error in southeastern China for both WAB and WPR. We also explored the effect of resampling waterfowl layers from 1 km to 30 km resolution for multi-scale risk modeling. Results indicated low average difference (less than 0.16 and 0.01 standard deviations for WAB and WPR, respectively), with greatest differences in the north for the breeding season and southeast for the wintering season. This work provides the first geospatial models of waterfowl abundance available for China. The indices provide important inputs for modeling disease transmission risk at the interface of poultry and wild birds. These models are easily adaptable, have broad utility to both disease and conservation needs, and will be available to the scientific community for advanced modeling applications.

  4. The Chernobyl accident ten years later

    SciTech Connect

    Squires, D.J.

    1996-12-31

    On April 26, 1986 at 1:23 AM a fire and explosion occurred at the fourth unit of the Chernobyl Nuclear Power Plant Complex, located in the Ukraine, that resulted in the destruction of the reactor core and most of the building in which it was housed. Several environmental impacts resulting from the accident will be discussed in this paper, which will include the effects on plant and wild life, radioactive waste generated and stored or disposed of, effects of evacuations relating to residents within the subsequently established 10km and 30km control zones, impacts of the emergency containment structure (sarcophagus), and potential effects on world opinion and future development of nuclear power. As an immediate result of the fire, 31 people died (2 from the fire & smoke, and 29 from excessive radiation); 237 cases of acute radiation sickness occurred; the total fatalities based upon induced chronic diseases as a result of the accident is unknown: more than 100,000 people were evacuated from within the subsequently established 30 km control zone; in excess of 50 million curies of radionuclides that included finely dispersed nuclear fuel, fragments of graphite, concrete and other building materials were released from the reactor into the environment; an estimated one million cubic meters of radioactive waste were generated (LLW, ILW, HLW); more than 5000 tons of materials (sand, boron, dolomite, cement, and lead) were used to put the fire out by helicopter; shutdown of the adjacent power plants were performed; and other environmental impacts occurred. The Chernobyl Nuclear Power Plant Unit No 4 is an RBMK-1000. It initiated operations in 1983, it was a 1000 MWe with a power output of 3200 MW(th), the reactor core contained 190 MT of fuel, with 1659 assemblies (plus 211 control rods), the average burnup rate was 10.3 MWd/kg, and the reactor operated on a continuous basis with maintenance and fuel reload performed during operations.

  5. Comparison Of The Global Analytic Models Of The Main Geomagnetic Field With The Stratospheric Balloon Magnetic Data 335

    NASA Astrophysics Data System (ADS)

    Tsvetkov, Yu.; Filippov, S.; Frunze, A.

    2013-12-01

    Three global analytical models of a main geomagnetic field constructed by satellite data are used: model IGRF, Daily Mean Spherical Harmonic Models (DMSHM), and model EMM/2010, and also scalar data of geomagnetic field and its gradients, received in stratospheric balloon gradient magnetic surveys at altitudes of ~30 km. At these altitudes the regional magnetic field is formed from all sources of the Earth's crust. It enables to receive along lengthy routes of surveys the fullest data on regional and longwave-lenght magnetic anomalies. Model DMSHM is used at extracting of magnetic anomalies for elimination of a secular variation up to significant value 0,2 nT. The model can be constructed within the limits of ± 1 months from the moment stratospheric balloon surveys with beneficial day terms with magnetic activity up to Kp <20, that leads to an error of representation of main MFE equal ±5 нТл. It is possible at presence acting for the period of stratospheric balloon magnetic survey of the satellite, for example, Swarm. On stratospheric balloon data it is shown, that model EMM/2010 unsatisfactorily displays MFE at altitude of 30 km. Hence, the qualitative model of the constant (main and anomaly) magnetic field cannot be constructed only with use of satellite and ground data. The improved model constant MFE, constructed according to satellite and stratospheric balloon magnetic surveys, developed up to a degree and the order m=n=720, will have a reliable data about regional crust magnetic field, hence, and about deep magnetic structure of the Earth's crust. The use gradient magnetic surveys aboard stratospheric balloons allows to find the places alternating approximately through 3000 km in which there are no magnetic anomalies. In these places probably to supervise satellite magnetic models for a range of altitude of 20-40 km, timed to stratospheric balloon magnetic surveys.

  6. Antarctic Ice Sheet Surface Mass Balance Estimates from 2003 TO 2015 Using Icesat and CRYOSAT-2 Data

    NASA Astrophysics Data System (ADS)

    Xie, Huan; Hai, Gang; Chen, Lei; Liu, Shijie; Liu, Jun; Tong, Xiaohua; Li, Rongxing

    2016-06-01

    An assessment of Antarctic ice sheet surface mass balance from 2003 to 2015 has been carried out using a combination of ICESat data from 2003 to 2009 and CryoSat-2 data from 2010 to 2015. Both data sets are of L2 and are currently processed separately using different models. First, a repeat-track processing method that includes terms accounting for the trend and the first order fit of topography is applied to repeat-track measurements of all ICESat Campaigns. It uses the Least Squares fitting of the model to all observations in a box of 500 m x 500 m. The estimated trends in these boxes are then averaged inside a 30 km x 30 km cell. Similarly, the cells are used to estimate basin and ice sheet level surface elevation change trends. Mass balance calculating is performed at the cell level by multiplying the ice density by the volume change and then extended to the basin and the ice sheet level. Second, in CryoSat-2 data processing we applied a model within a cell of 5 km x 5 km considering that CryoSat-2 does not maintain repeated tracks. In this model the elevation trend, and a higher order topography are solved in an iterative way using the least squares technique. The mass change is computed at the cell level in the same way as the ICESat data. GIA correction is applied for both ICESat and CryoSat-2 estimates. Detailed information about the data processing, elevation and mass balance changes, and comparison with other studies will be introduced.

  7. Spatial Modeling of Wild Bird Risk Factors for Highly Pathogenic A(H5N1) Avian Influenza Virus Transmission.

    PubMed

    Prosser, Diann J; Hungerford, Laura L; Erwin, R Michael; Ottinger, Mary Ann; Takekawa, John Y; Newman, Scott H; Xiao, Xiangming; Ellis, Erle C

    2016-05-01

    One of the longest-persisting avian influenza viruses in history, highly pathogenic avian influenza virus (HPAIV) A(H5N1), continues to evolve after 18 yr, advancing the threat of a global pandemic. Wild waterfowl (family Anatidae) are reported as secondary transmitters of HPAIV and primary reservoirs for low-pathogenic avian influenza viruses, yet spatial inputs for disease risk modeling for this group have been lacking. Using geographic information software and Monte Carlo simulations, we developed geospatial indices of waterfowl abundance at 1 and 30 km resolutions and for the breeding and wintering seasons for China, the epicenter of H5N1. Two spatial layers were developed: cumulative waterfowl abundance (WAB), a measure of predicted abundance across species, and cumulative abundance weighted by H5N1 prevalence (WPR), whereby abundance for each species was adjusted based on prevalence values and then totaled across species. Spatial patterns of the model output differed between seasons, with higher WAB and WPR in the northern and western regions of China for the breeding season and in the southeast for the wintering season. Uncertainty measures indicated highest error in southeastern China for both WAB and WPR. We also explored the effect of resampling waterfowl layers from 1 to 30 km resolution for multiscale risk modeling. Results indicated low average difference (less than 0.16 and 0.01 standard deviations for WAB and WPR, respectively), with greatest differences in the north for the breeding season and southeast for the wintering season. This work provides the first geospatial models of waterfowl abundance available for China. The indices provide important inputs for modeling disease transmission risk at the interface of poultry and wild birds. These models are easily adaptable, have broad utility to both disease and conservation needs, and will be available to the scientific community for advanced modeling applications. PMID:27309075

  8. Exploring a Multi-resolution Approach Using AMIP Simulations

    SciTech Connect

    Sakaguchi, Koichi; Leung, Lai-Yung R.; Zhao, Chun; Yang, Qing; Lu, Jian; Hagos, Samson M.; Rauscher, Sara; Dong, Li; Ringler, Todd; Lauritzen, P. H.

    2015-07-31

    This study presents a diagnosis of a multi-resolution approach using the Model for Prediction Across Scales - Atmosphere (MPAS-A) for simulating regional climate. Four AMIP experiments are conducted for 1999-2009. In the first two experiments, MPAS-A is configured using global quasi-uniform grids at 120 km and 30 km grid spacing. In the other two experiments, MPAS-A is configured using variable-resolution (VR) mesh with local refinement at 30 km over North America and South America embedded inside a quasi-uniform domain at 120 km elsewhere. Precipitation and related fields in the four simulations are examined to determine how well the VR simulations reproduce the features simulated by the globally high-resolution model in the refined domain. In previous analyses of idealized aqua-planet simulations, the characteristics of the global high-resolution simulation in moist processes only developed near the boundary of the refined region. In contrast, the AMIP simulations with VR grids are able to reproduce the high-resolution characteristics across the refined domain, particularly in South America. This indicates the importance of finely resolved lower-boundary forcing such as topography and surface heterogeneity for the regional climate, and demonstrates the ability of the MPAS-A VR to replicate the large-scale moisture transport as simulated in the quasi-uniform high-resolution model. Outside of the refined domain, some upscale effects are detected through large-scale circulation but the overall climatic signals are not significant at regional scales. Our results provide support for the multi-resolution approach as a computationally efficient and physically consistent method for modeling regional climate.

  9. Conductive Channel for Energy Transmission

    NASA Astrophysics Data System (ADS)

    Apollonov, Victor V.

    2011-11-01

    For many years the attempts to create conductive channels of big length were taken in order to study the upper atmosphere and to settle special tasks, related to energy transmission. There upon the program of creation of "Impulsar" represents a great interest, as this program in a combination with high-voltage high repetition rate electrical source can be useful to solve the above mentioned problems (N. Tesla ideas for the days of high power lasers). The principle of conductive channel production can be shortly described as follows. The "Impulsar"—laser jet engine vehicle—propulsion take place under the influence of powerful high repetition rate pulse-periodic laser radiation. In the experiments the CO2—laser and solid state Nd:YAG laser systems had been used. Active impulse appears thanks to air breakdown (<30 km) or to the breakdown of ablated material on the board (>30 km), placed in the vicinity of the focusing mirror-acceptor of the breakdown waves. With each pulse of powerful laser the device rises up, leaving a bright and dense trace of products with high degree of ionization and metallization by conductive nano-particles due to ablation. Conductive dust plasma properties investigation in our experiments was produced by two very effective approaches: high power laser controlled ablation and by explosion of wire. Experimental and theoretical results of conductive canal modeling will be presented. The estimations show that with already experimentally demonstrated figures of specific thrust impulse the lower layers of the Ionosphere can be reached in several ten seconds that is enough to keep the high level of channel conductivity and stability with the help of high repetition rate high voltage generator. Some possible applications for new technology are highlighted.

  10. Isotasy and its implications for the structure of the Sierra, Nevada

    SciTech Connect

    Jones, C.H. . Center for Neotectonic Studies)

    1993-04-01

    Much of the understanding of the structure of the Sierra Nevada has evolved from the assumption of a thick crustal root; gravity models of the Sierra have generally started from such a root and then calculated density anomalies in the upper crust necessary to completely fit gravity measurements. Recent challenges to the seismic basis as this assumption suggest that alternate models of isostasy for the Sierra be explored. Direct observation of crustal structure at great depth is only possible in the Tehachapi Mtns., where paleodepths of 25--30 km have been reported, densities still range over [approximately]0.2 g/cm[sup 3], and the west-to-east difference in the Bouguer gravity anomaly is only [approximately]50 mgal (compared to > 150 mgal farther north). If these variations accurately reflect conditions present today at [approximately]15--30 km under the central Sierra, then surface density differences between foothills and Sierran crest could extend to 30--40 km depth. Published seismic refraction profiles support a bulk difference of [approximately]0.1 g/cm[sup 3] through the crust. Thus variations of bulk properties in the surface exposures of the Sierran batholith and countryrock might represent variations throughout the upper crust and possibly the entire crust. Because these variations are virtually unquestionably Mesozoic in age, such a structure has profound implications for the Cenozoic history of the range. For example, placing these crustal densities over a thick root in mid-Cenozoic history of the range. For example, structure has profound implications for the Cenozoic history of the range. For example, placing these crustal densities over a thick root in mid-Cenozoic time when the Sierra was only [approximately]1 km high, would make the mid-Cz Sierra tremendously overcompensated.

  11. Lidar observations of persistent gravity waves with periods of 3-10 h in the Antarctic middle and upper atmosphere at McMurdo (77.83°S, 166.67°E)

    NASA Astrophysics Data System (ADS)

    Chen, Cao; Chu, Xinzhao; Zhao, Jian; Roberts, Brendan R.; Yu, Zhibin; Fong, Weichun; Lu, Xian; Smith, John A.

    2016-02-01

    Persistent, dominant, and large-amplitude gravity waves with 3-10 h periods and vertical wavelengths ~20-30 km are observed in temperatures from the stratosphere to lower thermosphere with an Fe Boltzmann lidar at McMurdo, Antarctica. These waves exhibit characteristics of inertia-gravity waves in case studies, yet they are extremely persistent and have been present during every lidar observation. We characterize these 3-10 h waves in the mesosphere and lower thermosphere using lidar temperature data in June from 2011 to 2015. A new method is applied to identify the major wave events from every lidar run longer than 12 h. A continuous 65 h lidar run on 28-30 June 2014 exhibits a 7.5 h wave spanning ~60 h, and 6.5 h and 3.4 h waves spanning 40 and 45 h, respectively. Over the course of 5 years, 323 h of data in June reveal that the major wave periods occur in several groups centered from ~3.5 to 7.5 h, with vertical phase speeds of 0.8-2 m/s. These 3-10 h waves possess more than half of the spectral energy for ~93% of the time. A rigorous prewhitening, postcoloring technique is introduced for frequency power spectra investigation. The resulting spectral slopes are unusually steep (-2.7) below ~100 km but gradually become shallower with increasing altitude, reaching about -1.6 at 110 km. Two-dimensional fast Fourier transform spectra confirm that these waves have a uniform dominant vertical wavelength of 20-30 km across periods of 3.5-10 h. These statistical features shed light on the wave source and pave the way for future research.

  12. Heterogeneous conversion of N2O5 to HNO3 in the post-Mount Pinatubo eruption stratosphere

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Gunson, M. R.; Abrams, M. C.; Lowes, L. L.; Zander, R.; Mahieu, E.; Goldman, A.; Ko, M. K. W.; Rodriguez, J. M.; Sze, N. D.

    1994-01-01

    Simultaneous stratospheric volume mixing ration (VMR) profiles of dinitrogen pentoxide (N2O5) and nitric acid (HNO3) at sunrise between 25 deg N and 15 deg S latitude and profiles of HNO3 at sunset between 42 deg S and 53 deg S latitude have been derived from 0.01/cm resolution infrared solar occultation spectra recorded 9.5 months after the massive eruption of the Mount Pinatubo volcano in the Philippine Islands. The measurements were obtained by the atmospheric trace molecule spectroscopy (ATMOS) Fourier transform spectrometer during the ATLAS 1 shuttle mission (March 24 to April 2, 1992). The measured HNO3 VMRs are higher at all altitudes and latitudes than corresponding values measured by the limb infrared monitor of the stratosphere (LIMS) instrument during the same season in 1979, when the aerosol loading was near background levels. The largest relative increase in the HNO3 VMR occurred near the equator at 30-km altitude, where the ATMOS/ATLAS 1 values are about a factor of 2 higher than the LIMS measurements. Two-dimensional model calculations show that the increase in HNO3 and the ATMOS/ATLAS 1 measurement of a steep decrease in the N2O5 VMR below 30 km can be explained by the enhanced conversion of N2O5 to HNO3 on the surfaces of the Mount Pinatubo sulfate aerosols. Our profile results demonstrate the global impact of the N2O5 + H2O yields 2HNO3 heterogeneous reaction in altering the partitioning of stratospheric odd nitrogen after a major volcanic eruption.

  13. Vertical crustal movements preceding and accompanying the San Fernando earthquake of February 9, 1971: A summary

    USGS Publications Warehouse

    Castle, R.O.; Church, J.P.; Elliott, M.R.; Morrison, N.L.

    1975-01-01

    Comparative elevations referred chiefly to a tidal bench mark with a history of relatively positive movement show that much of the Transverse Ranges of southern California sustained major changes in elevation both before and in association with the ML 6.4 San Fernando earthquake of February 9, 1971. Preseismic changes in elevation in the southern Transverse Ranges were almost uniformly positive and generally episodic. Maximum uplift measured between 1960/61 and 1968/69 was 0.205 m (observed) or 0.200 m (adjusted); it occurred about 30 km northeast of the 1971 epicenter. As much as 0.129 m (observed) of preseismic uplift was also measured about 30 km northwest of the epicenter between 1964 and 1968. A comparison between 1968 and 1969 elevation data revealed 0.078 m (observed) of differential uplift centered about 10 km west of the epicenter; earlier leveling indicates that this uplift began between February 1967 and May 1968. Changes in elevation measured during the interval 1968/69-71 (postearthquake) are interpreted as chiefly coseismic and were concentrated along a 15-km ruptured segment of the east-trending, north-dipping San Fernando fault. These changes were characterized by subsidence of as much as 0.111 m (observed) or 0.092 m (adjusted) south of the fault and a ridge of uplift of up to at least 2.195 m (observed) or 2.196 m (adjusted) immediately north of the fault. The more episodic preseismic movements are interpretable as deep-seated creep events on the San Fernando fault. Alternatively, these episodic movements may be due partly to the operation of dilatancy; the onset of the 1968-1969 epicentral uplift accords closely with the initiation of a Vp Vs anomaly recognized in this same area. The 1968/69-71 elevation changes can be attributed almost entirely to slip on the San Fernando fault. ?? 1975.

  14. P and S velocity tomography of the Mariana subduction system from a combined land-sea seismic deployment

    NASA Astrophysics Data System (ADS)

    Barklage, Mitchell; Wiens, Douglas A.; Conder, James A.; Pozgay, Sara; Shiobara, Hajime; Sugioka, Hiroko

    2015-03-01

    Seismic imaging provides an opportunity to constrain mantle wedge processes associated with subduction, volatile transport, arc volcanism, and back-arc spreading. We investigate the seismic velocity structure of the upper mantle across the Central Mariana subduction system using data from the 2003-2004 Mariana Subduction Factory Imaging Experiment, an 11 month deployment consisting of 20 broadband seismic stations installed on islands and 58 semibroadband ocean bottom seismographs. We determine the three-dimensional VP and VP/VS structure using over 25,000 local and over 2000 teleseismic arrival times. The mantle wedge is characterized by slow velocity and high VP/VS beneath the fore arc, an inclined zone of slow velocity underlying the volcanic front, and a strong region of slow velocity beneath the back-arc spreading center. The slow velocities are strongest at depths of 20-30 km in the fore arc, 60-70 km beneath the volcanic arc, and 20-30 km beneath the spreading center. The fore-arc slow velocity anomalies occur beneath Big Blue seamount and are interpreted as resulting from mantle serpentinization. The depths of the maximum velocity anomalies beneath the arc and back arc are nearly identical to previous estimates of the final equilibrium depths of mantle melts from thermobarometry, strongly indicating that the low-velocity zones delineate regions of melt production in the mantle. The arc and back-arc melt production regions are well separated at shallow depths, but may be connected at depths greater than 80 km.

  15. Ionospheric VLF waves and optical phenomena over active thunderstorms. Ph.D. Thesis

    SciTech Connect

    Li, Y.Q.

    1993-01-01

    In 1987 and 1988, two campaigns, the Wave Induced Particle Precipitation campaign and the Thunderstorm 2 campaign, were conducted to investigate lightning-generated effects in the upper atmosphere and ionosphere. Two rockets (apogees 420km and 330km) and 6 balloons (float altitudes 30km) were launched near thunderstorms in these campaigns. Optical and electric signals from hundreds of lightning strokes were recorded by both the rockets and balloons. Using the data obtained in these two campaigns, the author has been able to study some problems about lightning-generated VLF waves in the ionosphere which have not been well investigated previously. In this dissertation, the author reports the following: the downward-looking optical detector on the rocket recorded some anomalous characteristic optical phenomena which had not been reported previously. This study shows that they occurred above the balloon altitude (30km), and the results are interpreted in terms of discharges at high altitudes. The author studied the relation between the amplitude of lightning-generated VLF waves in the ionosphere and the lightning current recorded by the SUNYA lightning network. This study shows that the amplitude of waves at frequencies below 5 kHz has linear response to the lightning current. Above 5 kHz, there is not a significant linear correlation between the wave amplitude and the lightning current. The author has been able to determine the propagation path of the lightning-generated VLF waves from the source to the rocket. The path is consistent with the leaky waveguide hypothesis in which waves travel in the waveguide to the vicinity of the rockets, and then propagate vertically through the ionosphere. The author has found that the amplitude of lightning generated VLF waves have maxima and minima at different altitudes instead of being attenuated monotonically with altitude as expected.

  16. Mapping Buried Impact Craters in the Chryse Basin to Understand the Distribution of Outflow Channel Sediment

    NASA Astrophysics Data System (ADS)

    Miller, Moira; Frey, Herbert V.

    2016-01-01

    The Chryse Basin's location in the northern hemisphere of Mars allowed it to collect water from a number of major outflow channels. These outflows likely deposited significant amounts of sediment within the Basin. This project's goal was to see if mapping buried impact craters, revealed as Quasi-Circular Depressions (QCDs) in Mars Orbiter Laser Altimeter (MOLA) data, could be used to determine the distribution and variation of sediment thickness within the Basin. QCDs, including likely buried impact craters, were mapped to test the hypothesis that further into the basin there would be fewer smaller craters because thicker sediments would have preferentially covered them. Mapping was done using Gridview, an interactive graphics program that manipulates data, in this case topographic data from MOLA. It should be possible to estimate the thickness of the sediment from the smallest buried craters found in a given area, and therefore map out the change in sediment thickness across the basin. The smallest QCDs beginning to be completely covered by sediment were just below 30 km in diameter. The minimum sediment needed to cover a QCD of this size was calculated to be between 1-2km. Therefore, the absence of QCDs below 30 km in the NE corner of Chryse could be explained by sediment at least that thick. Lower thickness is expected elsewhere in the basin, especially in the SW, where more QCDs with smaller diameters were found. The method of mapping buried impact craters provides a way to determine variations in sediment thickness within the Chryse Basin. This method could be used on other sediment-covered areas to learn about past water flow.

  17. Continental slope morphology in northern Gulf of Mexico mapped with long-range (GLORIA) side-scan data

    SciTech Connect

    McGregor, B.A.; Garrison, L.E.; Kenyon, N.H.

    1985-02-01

    GLORIA II long-range side-scan data provide a mosaic of the continental slope in the northern Gulf of Mexico, seaward of the Texas-Louisiana coast. A swath as wide as 30 km and a 10% overlap of the data between parallel track lines provide a continuous picture of the complex slope morphology, which is largely controlled by salt deformation. Morphologic features range from piercement structures approximately 2 km in diameter to basins as much as 30 km across. The GLORIA data delineate the East Breaks submarine slide, where surface lineations are suggestive of deformation features. High-resolution 10 kHz seismic-reflection profiles indicate that the very irregular surface on the slide has a relief of 10 m. The 3 types of intraslope basins (blocked canyon, interdomal, and collapse) described by A.H. Bouma can be identified on the GLORIA data. The walls of Gyre basin, an example of a blocked canyon, have what are interpreted to be gullies, which are commonly associated with submarine canyons. Another basin downslope has similar gully-like features on the walls, which suggest that it may have been part of the original canyon system. Although many canyon-like features direct the movement of sediment downslope, the present data show that all conduits end in closed basins. No system of basins can be shown to transport sediment across the entire slope between the Mississippi Canyon and the East Breaks slide. Small-scale slumps, which can be identified on the flanks of some of the diapiric structures, also contribute sediments to basins such as Gyre basin.

  18. Collision tectonics of the Central Indian Suture zone as inferred from a deep seismic sounding study

    USGS Publications Warehouse

    Mall, D.M.; Reddy, P.R.; Mooney, W.D.

    2008-01-01

    The Central Indian Suture (CIS) is a mega-shear zone extending for hundreds of kilometers across central India. Reprocessing of deep seismic reflection data acquired across the CIS was carried out using workstation-based commercial software. The data distinctly indicate different reflectivity characteristics northwest and southeast of the CIS. Reflections northwest of the CIS predominantly dip southward, while the reflection horizons southeast of the CIS dip northward. We interpret these two adjacent seismic fabric domains, dipping towards each other, to represent a suture between two crustal blocks. The CIS itself is not imaged as a sharp boundary, probably due to the disturbed character of the crust in a 20 to 30-km-wide zone. The time sections also show the presence of strong bands of reflectors covering the entire crustal column in the first 65??km of the northwestern portion of the profile. These reflections predominantly dip northward creating a domal structure with the apex around 30??km northwest of the CIS. There are a very few reflections in the upper 2-2.5??s two-way time (TWT), but the reflectivity is good below 2.5??s TWT. The reflection Moho, taken as the depth to the deepest set of reflections, varies in depth from 41 to 46??km and is imaged sporadically across the profile with the largest amplitude occurring in the northwest. We interpret these data as recording the presence of a mid-Proterozoic collision between two micro-continents, with the Satpura Mobile Belt being thrust over the Bastar craton. ?? 2008.

  19. Preliminary validation of the refractivity from the new radio occultation sounder GNOS/FY-3C

    NASA Astrophysics Data System (ADS)

    Liao, Mi; Zhang, Peng; Yang, Guang-Lin; Bi, Yan-Meng; Liu, Yan; Bai, Wei-Hua; Meng, Xiang-Guang; Du, Qi-Fei; Sun, Yue-Qiang

    2016-03-01

    As a new member of the space-based radio occultation sounders, the GNOS (Global Navigation Satellite System Occultation Sounder) mounted on Fengyun-3C (FY-3C) has been carrying out atmospheric sounding since 23 September 2013. GNOS takes approximately 800 daily measurements using GPS (Global Positioning System) and Chinese BDS (BeiDou navigation satellite) signals. In this work, the atmospheric refractivity profiles from GNOS were compared with the ones obtained from the co-located ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis. The mean bias of the refractivity obtained through GNOS GPS (BDS) was found to be approximately -0.09 % (-0.04 %) from the near surface to up to 46 km. While the average standard deviation was approximately 1.81 % (1.26 %), it was as low as 0.75 % (0.53 %) in the range of 5-25 km, where best sounding results are usually achieved. Further, COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) and MetOp/ GRAS (GNSS Receiver for Atmospheric Sounding) radio occultation data were compared with the ECMWF reanalysis; the results thus obtained could be used as reference data for GNOS. Our results showed that GNOS/FY-3C meets the design requirements in terms of accuracy and precision of the sounder. It possesses a sounding capability similar to COSMIC and MetOp/GRAS in the vertical range of 0-30 km, though it needs further improvement above 30 km. Overall, it provides a new data source for the global numerical weather prediction (NWP) community.

  20. Thermal perturbations beneath the incipient Okavango Rift Zone, northwest Botswana

    NASA Astrophysics Data System (ADS)

    Leseane, Khumo; Atekwana, Estella A.; Mickus, Kevin L.; Abdelsalam, Mohamed G.; Shemang, Elisha M.; Atekwana, Eliot A.

    2015-02-01

    We used aeromagnetic and gravity data to investigate the thermal structure beneath the incipient Okavango Rift Zone (ORZ) in northwestern Botswana in order to understand its role in strain localization during rift initiation. We used three-dimensional (3-D) inversion of aeromagnetic data to estimate the Curie Point Depth (CPD) and heat flow under the rift and surrounding basement. We also used two-dimensional (2-D) power-density spectrum analysis of gravity data to estimate the Moho depth. Our results reveal shallow CPD values (8-15 km) and high heat flow (60-90 mW m-2) beneath a ~60 km wide NE-trending zone coincident with major rift-related border faults and the boundary between Proterozoic orogenic belts. This is accompanied by thin crust (<30 km) in the northeastern and southwestern parts of the ORZ. Within the Precambrian basement areas, the CPD values are deeper (16-30 km) and the heat flow estimates are lower (30-50 mW m-2), corresponding to thicker crust (~40-50 km). We interpret the thermal structure under the ORZ as due to upward migration of hot mantle fluids through the lithospheric column that utilized the presence of Precambrian lithospheric shear zones as conduits. These fluids weaken the crust, enhancing rift nucleation. Our interpretation is supported by 2-D forward modeling of gravity data suggesting the presence of a wedge of altered lithospheric mantle centered beneath the ORZ. If our interpretation is correct, it may result in a potential paradigm shift in which strain localization at continental rift initiation could be achieved through fluid-assisted lithospheric weakening without asthenospheric involvement.

  1. Results and interpretation of geophysical studies near the Picacho Fault, south-central Arizona

    USGS Publications Warehouse

    Pankratz, Leroy W.; Ackermann, Hans D.; Jachens, Robert C.

    1978-01-01

    Earth fissuring attributed to ground-water withdrawal occurs throughout south-central Arizona. A large zone of active fissures is located near Picacho, Arizona on the eastern rim of a large subsidence bowl. The main fissure has been named the Picacho fault. During February and March 1977, approximately 6.5 km of seismic-refraction lines were run across the Picacho fault to investigate subsurface conditions down to the crystalline basement. In addition, two lines of close-spaced gravity stations were made across the fault. The gross geologic features inferred from the gravity data agree with the seismic interpretations. Six layers were interpreted from the seismic refraction data: three layers of unconsolidated alluvium, two of denser rock of varying porosity, and the basement rock. Three significant basement faults were identified. These faults appear to lie almost directly beneath the surface fissures. Abrupt slope changes in the alluvial layers and an abrupt velocity change in the denser compacted sediments seem to be related spatially to the surface fissures. In addition there are lateral velocity differences within the basement fault blocks. In the overlying sediments a facies change in a 3.0 km/sec layer is suggested by the abrupt lateral velocity increase from 3.0 km/sec to 3.7 km/sec. This apparent facies change may in fact represent a fault plane extending upwards from the westernmost basement fault. This fault plane may even extend farther into the unconsolidated overlying sediments, inferred from basinward increases in slope, subtle basinward decreases in velocity, and a basinward elevation decrease in the top of the zone of saturation.

  2. An area with high density of craters on the lunar surface.

    NASA Astrophysics Data System (ADS)

    Feoktistova, Ekaterina

    2015-04-01

    In previous studies [1, 2] on the lunar surface were detected areas with high density of craters. One such area is located to the north of the Mare Orientale and to the west of the Mare Imbrium in the highland region placed between 0° N and 70° N, and between 160° E and 290° E. In this area there are such large craters as Mach (182 km) and Landau (225 km). According to data from GRAIL mission [3], the crust thickness in this area varies from 30 km in the eastern part up to 60 km in the western part. We investigated the distribution of the impact craters in this region using the Morphological Catalogue of Lunar Craters [4]. The characteristics, such as crater number, coordinates, diameter and morphological features, for 15000 craters with diameter more than 10 km are contained in this catalogue. All the craters in the catalogue were divided into five class of degradation: from class 1 (youngest craters) to class 5 (oldest, most destroyed craters). According to our research, the number of craters with a diameter of more than 10 km in the area reaches 4604, accounting for 31% of the total number of craters with a diameter of more than 10 km on the moon. Thus the crater density in this region is 658 craters per 1 million km². This value is much higher than the estimates of the mean crater densities for the lunar highlands (442 craters per 1 million km²), maria (73 craters per 1 million km²) and South Pole Aitken basin (393 craters per 1 million km²) obtained in previous studies [2,5]. The study of the distribution of craters by diameter revealed that the density of craters with a diameter of ≥ 30 km in the same area as a whole on the Moon. At the same time, in this area there is a significant increase in the craters with a diameter of 10 30 km: 35 % of the total number of craters on the moon. The main part of them are high-preserved craters: 1, 2 and 3 class of degradation (41, 34, and 40% of the total number of craters of these classes on the entire

  3. Crustal transects across the Rif domains in North Morocco, from the RIFSIS seismic survey

    NASA Astrophysics Data System (ADS)

    Gil de la Iglesia, A.; Gallart, J.; Diaz Cusi, J.; Carbonell, R.; Levander, A.; Palomeras, I.; Harnafi, M.

    2013-12-01

    In October 2011, two 300 km-long NS and EW wide-angle seismic transects were carried out in N Morocco, across main domains of Rif cordillera, in a joint effort from Spanish-Moroccan-USA scientists. Main goal of the RIFSIS survey was to achieve, for the first time, detailed crustal velocity-depth models on the southern flank of the Gibraltar Arc System. This asymmetric, arcuated system surrounding the Alboran Sea and composed by the Betic ranges on the N and the Rif cordillera on the S has undergone a complex tectonic evolution since Miocene times. Different types of evolutionary models have been proposed in the last decades, poorly constrained by the available geophysical results, specially on the southern flank, where crustal depths around 30 km have been proposed from inversion modeling of potential field datasets, in contrast with greater values up to 40 km depths and significant lateral variations from RF analysis. In the RIFSIS survey, almost 1000 Texans stations were deployed along the two profiles and 3 shots of 1 T were detonated along each one. The NS transect was extended northwards in Spain by a 75 km long segment in the Betics, and southwards it connects with an analogous profile recorded in 2010 across the Atlas Mountains (SIMA project), hence providing a 700 km long continuous seismic transect sampling the different tectonic domains. The high density of recording stations allows building up of vertical seismic sections focused on the Moho PmP reflections that reveal important variations along this transect. An extensive analysis based on travel time forward modeling has also been performed and main results are presented here. The interpreted crustal structure differentiates two sedimentary layers on top of the basement, inferred from the observed first arrivals at short offsets, followed by upper, mid and lower crustal levels constrained by reflected phases visible in the record sections. The bottom of the crust is well defined from PmP phases

  4. Seismic and Geodetic Investigation of the 1996-1998 Earthquake Swarm at Strandline Lake, Alaska

    NASA Astrophysics Data System (ADS)

    Kilgore, W.; Roman, D. C.; Power, J. A.; Hansen, R. A.; Biggs, J.

    2009-12-01

    Microearthquake (< M3.0) swarms occur frequently in volcanic environments, but do not always culminate in an eruption. Such non-eruptive swarms may be caused by stresses induced by magma intrusion, hydrothermal fluid circulation, or regional tectonic processes, such as slow-slip earthquakes. Strandline Lake, located 30 km northeast of Mount Spurr volcano in south-central Alaska, experienced a strong earthquake swarm between August 1996 and August 1998. The Alaska Volcano Observatory (AVO) catalog indicates that a total of 2,999 earthquakes were detected during the swarm period, with a maximum magnitude of Mw 3.1 and a depth range of 0-30 km below sea level (with the majority of catalog hypocenters located between 5-10 km BSL). The cumulative seismic moment of the swarm was 2.03e15 N m, equivalent to a cumulative magnitude of Mw 4.2. Because of the swarm's distance from the nearest Holocene volcanic vent, seismic monitoring was poor and gas and deformation data for the swarm period do not exist. However, combined waveforms from a dense seismic network on Mount Spurr and from several regional seismic stations allowed us to re-analyze the swarm earthquakes. We first developed a new 1-D velocity model for the Strandline Lake region by re-picking and inverting precise arrival times for 27 large Strandline Lake earthquakes. The new velocity model reduced the average RMS for these earthquakes from 0.16 to 0.11s, and the average horizontal and vertical location errors from 3.3 to 2.5 km and 4.7 to 3.0 km, respectively. Depths of the 27 earthquakes ranged from 10.5 to 22.1 km with an average depth of 16.6 km. A moderately high b-value of 1.33 was determined for the swarm period, possibly indicative of magmatic activity. However, a similarly high b-value of 1.25 was calculated for the background period. 28 well-constrained fault plane solutions for both swarm and background earthquakes indicate a diverse mixture of strike-slip, dip-slip, and reverse faulting beneath

  5. Constraints on plateau architecture and assembly from deep crustal xenoliths, northern Altiplano (SE Peru)

    NASA Astrophysics Data System (ADS)

    Chapman, Alan; Ducea, Mihai; McQuarrie, Nadine; Coble, Matthew; Petrescu, Lucian; Hoffman, Derek

    2016-04-01

    Newly discovered xenoliths within Pliocene and Quaternary intermediate volcanic rocks from southern Peru permit examination of lithospheric processes by which thick crust (60-70 km) and high average elevations (3-4 km) resulted within the Altiplano, the second most extensive orogenic plateau on Earth. The most common petrographic groups of xenoliths studied here are igneous or meta-igneous rocks with radiogenic isotopic ratios consistent with recent derivation from asthenospheric mantle (87Sr/ 86Sr = 0.704-0.709, 143Nd/144Nd = 0.5126-0.5129). A second group, consisting of felsic granulite xenoliths exhibiting more radiogenic compositions (87Sr/86Sr = 0.711-0.782, 143Nd/144Nd = 0.5121-0.5126), is interpreted as supracrustal rocks that underwent metamorphism at ~9 kbar (~30-35 km paleodepth, assuming a mean crustal density of 2.8 g/cm3) and ~750 °C. These rocks are correlated with nonmetamorphosed rocks of the Mitu Group and assigned a Mesozoic (Upper Triassic or younger) age based on detrital zircon U-Pb ages. A felsic granulite Sm-Nd garnet whole-rock isochron of 42 ± 2 Ma demonstrates that garnet growth took place in Eocene time. Monazite grains associated with quenched anatectic melt networks in the same rocks yield ion microprobe U-Pb ages ranging from 3.2 ± 0.2 to 4.4 ± 0.3 Ma (2σ). These disparate geochronologic data sets are reconciled by a model wherein Mesozoic cover rocks were transferred to >30 km depth beneath the plateau in the Eocene and progressively heated until at least Pliocene time. Isothermal decompression and partial melting ensued as these rocks were entrained as xenoliths in volcanic host magmas and transported toward the surface. Mafic granulites and peridotites from the same xenolith suite comprise the basement of the metasedimentary sequence, exhibiting isotopic characteristics of Central Andean crust. Calculated equilibrium pressures for these basement rocks are >11 kbar, suggesting that the basement-cover interface lies beneath the

  6. Arc-arc Collision Structure in the Southernmost Part of the Kuril Trench Region -Results from Integrated Analyses of the 1998-2000 Hokkaido Transect Seismic Data-

    NASA Astrophysics Data System (ADS)

    Iwasaki, Takaya; Tsumura, Noriko; Ito, Tanio; Sato, Hiroshi; Kurashimo, Eiji; Hirata, Naoshi; Arita, Kazunori; Noda, Katsuya; Fujiwara, Akira; Abe, Susumu; Kikkuchi, Shunsuke; Suzuki, Kazuko

    2015-04-01

    The Hokkaido Island, located in the southernmost part of the Kuril trench region, has been under a unique tectonic environment of arc-arc collision. Due to the oblique subduction of the Pacific (PAC) plate, the Kuril forearc sliver started to collide against Northeast (NE) Japan arc from the east at the time of middle Miocene to form complicated structures in the Hidaka collision zone (HCZ), as characterized by the westward obduction of the crustal rocks of the Kuril arc (the Hidaka metamorphic belt (HMB)) along the Hidaka main thrust (HMT) and a thick foreland fold-and-thrust belt. In and around the HCZ, a series of seismic reflection/refraction experiments were undertaken from 1994 to 2000, which provided important structural features including crustal delamination in the southern HCZ and a thick fold-and-thrust belt with velocity reversals (low velocity layers) in the northern HCZ. Reprocessing/reinterpretation for these data sets, which started in 2012, is aimed to construct a more detailed collision model through new processing and interpretation techniques. A multi-disciplinary project of the 1998-2000 Hokkaido Transect, crossing the northern part of the HCZ in EW direction, collected high-quality seismic data on a 227-km seismic refraction/wide-angle reflection profile and three seismic reflection lines. Our reanalyses revealed interesting collision structure ongoing in the northern part of the HCZ. The westward obduction of the Kuril arc crust was clearly imaged along the HMT. This obduction occurs at a depth of 27-30 km, much deeper than in the southern HCZ (23-25 km). The CRS/MDRS processing to the reflection data firstly succeeded in imaging clear reflection events at a 30-45 km depth below the obducted Kuril arc crust. These events show an eastward dip, probably corresponding to the lower crust/Moho within the NE Japan arc descending down to the east under the collision zone. Gently eastward dipping structures above these events (in a depth range of 5

  7. Atmospheric behavior of the Chelyabinsk impactor

    NASA Astrophysics Data System (ADS)

    Borovička, J.; Spurný, P.; Brown, P.; Kalenda, P.; Shrbený, L.

    2014-07-01

    The impact of a 19-m diameter asteroid near Chelyabinsk, Russia on February 15, 2013 has already been studied extensively [e.g., 1--3]. The main sources of information were casually recorded videos, which provided the images of the superbolide as well as acoustic records of the sonic booms. From these data, the bolide trajectory, velocity, deceleration, and lightcurve have been derived after careful calibration and analysis. Such detailed data are not available for any other impactor larger than about 5 meters. The Chelyabinsk event represents therefore a unique opportunity to study the interaction of asteroids in the decameter size range through the terrestrial atmosphere. In comparison with our previous study [1], we used more calibrated videos in this work. We will present the refined trajectory, velocity, and orbit but will mainly concentrate on the atmospheric fragmentation analysis. The extent of the dust trail up to the heights of 70 km demonstrates that significant mass loss occurred from the early parts of the luminous trajectory. Nevertheless, no flare was seen on the early portion of the lightcurve, suggesting that no sudden disruption occurred here and the mass was probably being lost from the asteroid surface. The first break-up occurred at the height of about 47 km. The large scale disruption, documented both by the lightcurve and sonic booms, occurred between the heights of 39--30 km. The fragmentation then ceased temporarily, but a number of surviving meter-sized boulders fragmented extensively again below 26 km. We will present a fragmentation model fitting both the observed lightcurve and deceleration. At lower heights, the deceleration of several individual fragments could be measured. The transverse speed of the major fragment was 400 m/s, much larger than expected, but of the same order of magnitude as observed in other cases including a sample of tiny meteoroids [4]. The unique aspect of Chelyabinsk was the formation of an extended dust trail

  8. Gravity waves from 30 to 160 km observed by an Fe lidar at McMurdo, Antarctica

    NASA Astrophysics Data System (ADS)

    Chu, X.; Chen, C.; Yu, Z.; Fong, W.; Roberts, B. R.; Lu, X.; Fuller-Rowell, T. J.; Vadas, S. L.; McDonald, A.; Gardner, C. S.

    2012-12-01

    Observations of gravity waves in the neutral atmosphere were usually limited to ~105 km where lidars can have appreciable signals. The first discovery of neutral Fe layers with gravity wave signatures in the thermosphere up to 160 km by an Fe Boltzmann lidar campaign at McMurdo, Antarctica has significantly pushed the limit to ~160 km. Two channels of Fe signals allow us to derive the Fe density from ~75 to 160 km and Fe temperature from ~80 to 150 km using the Fe Boltzmann technique. Furthermore, operating at UV 372 and 374 nm, this Alexandrite-laser-based Fe Boltzmann lidar produces strong Rayleigh scattering signals from air molecules. High-resolution measurements of temperatures are thus achieved from 30 to ~70 km utilizing the Rayleigh integration technique. As a consequence, the McMurdo Fe lidar data provide the first opportunity to trace gravity waves from ~30 km all the way up to ~160 km with a single ground-based instrument, which is the main focus of the current study. McMurdo (77.83S, 166.66E) is in the gap region between the South Pole and the Antarctic Circle. Located on the Ross Island, McMurdo is next to the most southerly active volcano Mt. Erebus, also to the east of the Trans-Antarctic Mountains, and by the poleward edge of the aurora oval as its geomagnetic latitude is near 80 deg. McMurdo turns out to be a 'hot spot' for waves, and large amplitude waves are frequently observed from the stratosphere to the thermosphere. All these factors may have contributed to, or influence, the very rich wave activities, the formation of converged Fe layers in the thermosphere, and the elevated thermospheric temperatures revealed by the lidar data of temperature and Fe density. Starting from late December 2010, the University of Colorado lidar group has collected over 1900 hours of data in the first 19 months at McMurdo, establishing a database for gravity wave studies. In this paper we will characterize gravity wave parameters from ~30 km up to 160 km for the

  9. GRAM 88 - 4D GLOBAL REFERENCE ATMOSPHERE MODEL-1988

    NASA Technical Reports Server (NTRS)

    Johnson, D. L.

    1994-01-01

    The Four-D Global Reference Atmosphere program was developed from an empirical atmospheric model which generates values for pressure, density, temperature, and winds from surface level to orbital altitudes. This program can generate altitude profiles of atmospheric parameters along any simulated trajectory through the atmosphere. The program was developed for design applications in the Space Shuttle program, such as the simulation of external tank re-entry trajectories. Other potential applications are global circulation and diffusion studies; also the generation of profiles for comparison with other atmospheric measurement techniques such as satellite measured temperature profiles and infrasonic measurement of wind profiles. GRAM-88 is the latest version of the software GRAM. The software GRAM-88 contains a number of changes that have improved the model statistics, in particular, the small scale density perturbation statistics. It also corrected a low latitude grid problem as well as the SCIDAT data base. Furthermore, GRAM-88 now uses the U.S. Standard Atmosphere 1976 as a comparison standard rather than the US62 used in other versions. The program is an amalgamation of two empirical atmospheric models for the low (25km) and the high (90km) atmosphere, with a newly developed latitude-longitude dependent model for the middle atmosphere. The Jacchia (1970) model simulates the high atmospheric region above 115km. The Jacchia program sections are in separate subroutines so that other thermosphericexospheric models could easily be adapted if required for special applications. The improved code eliminated the calculation of geostrophic winds above 125 km altitude from the model. The atmospheric region between 30km and 90km is simulated by a latitude-longitude dependent empirical model modification of the latitude dependent empirical model of Groves (1971). A fairing technique between 90km and 115km accomplished a smooth transition between the modified Groves values and

  10. Present-day strain distribution across a segment of the central bend of the North Anatolian Fault Zone from a Persistent-Scatterers InSAR analysis of the ERS and Envisat archives

    NASA Astrophysics Data System (ADS)

    Peyret, M.; Masson, F.; Yavasoglu, H.; Ergintav, S.; Reilinger, R.

    2013-03-01

    The North Anatolian Fault Zone (NAFZ) is the major transform system that accommodates the westward movement of the relatively rigid Anatolian block with respect to Eurasia. Mitigating the hazard associated with devastating earthquakes requires understanding how the NAFZ accumulates and releases the potential energy of elastic deformation both in space and in time. In this study, we focus on the central bend of the NAFZ where the strike of the North Anatolian Fault (NAF) changes from N75° to N105° within less than 100 km, and where a secondary fault system veers southwards within the interior of Anatolia. We present interseismic velocity fields obtained from a Persistent-Scatterers (PS) Interferometric radar analysis of ERS and Envisat radar archives. Despite the high vegetation cover, the spatial density of measurements is high (˜10 PS/km2 in average). Interseismic velocities presented below indicate a velocity change of ˜6-8 mm/yr along the satellite line-of-sight (LOS) mainly centred on the NAF surface trace, and are in good agreement with the GPS velocity field published previously. The observed deformation is accommodated within a zone of ˜20 to 30 km width, in this area where no surface creep has been reported, contrary to the Ismetpasa segment located ˜30 km to the west of this study zone. Although less conspicuous, ˜2-3 mm/yr (˜1 mm/yr along the LOS) of the total deformation seems to be localized along the Lacin Fault. The overall agreement with horizontal GPS measurements suggests that the vertical component of the ground deformation is minor. This is confirmed, over the western part of our study zone, by the 3-D estimation of the ground deformation from the combination of the GPS- and the PS-mean velocity fields. However, a specific pattern of the PS velocity fields suggests that an area, enclosed between two faults with roughly south-north orientation, experiences uplift. The PS analyses of radar time-series both prior and posterior to the Izmit

  11. The case for a deep-atmospheric in situ mission to address the highest priority Decadal Survey questions for Venus (Invited)

    NASA Astrophysics Data System (ADS)

    Atreya, S. K.; Garvin, J. B.; Glaze, L. S.; Campbell, B. A.; Fisher, M. E.; Flores, A.; Gilmore, M. S.; Johnson, N.; Kiefer, W. S.; Lorenz, R. D.; Mahaffy, P. R.; Ravine, M. A.; Webster, C. R.; Zolotov, M. Y.

    2013-12-01

    , especially within 30 km of the surface. Competing temperature-pressure dependent reactions and atmospheric circulation may cause vertical and latitudinal gradients of chemically-active trace gases (e.g., SO2, H2S, OCS, CO). Measurements of the chemical composition of the near-surface atmosphere can be used to evaluate the stability of primary and secondary minerals and can help to understand chemistry of atmosphere-surface interactions. However, concentrations of many trace species have never been measured below ~30 km, and multiple in situ measurements are required to evaluate chemical processes and cycles of volatiles, which can only be accomplished with deep entry probes. Current lack of understanding about Venus not only limits our understanding of evolutionary pathways Earth could experience, but also suggests that we are ill-equipped to understand the evolution of star systems with similar-sized planets.

  12. The polar Sudden Stratospheric Warming (SSW) and it's possible manifestations in the equatorial Mesosphere-Thermosphere-Ionosphere

    NASA Astrophysics Data System (ADS)

    Pant, Tarun

    In this study, the variations in daytime mesopause temperature and the Equatorial Electrojet over equator during Sudden Stratospheric Warming (SSW) events over high latitudes have been investigated. To reflect upon the stratospheric conditions NCEP-NCAR reanalysis data have also been used. This study indicates a possible dynamical coupling between the two regions through the planetary wave activity. The amplified wave signatures of quasi-16 day period are seen in the equatorial mesopause temperature and zonal mean polar stratospheric temperature (at 10 hPa) during the course of SSW. The possibility that the planetary waves over the polar stratosphere, which play an important role in the generation of SSW, could also have contribu-tion from the tropics has been indicated through numerical simulations in the past [Dunkerton, 1981], but due to the paucity of global measurements it could not be established unequivocally. These simulations also indicated the presence of a zero-wind line whose real counterparts were not observed in the atmosphere. The NCEP-NCAR reanalysis of stratospheric wind and tem-peratures clearly shows that (i) a dynamical feature similar to the zero-wind line appears over the tropics 60 days prior to the major warming and progresses poleward and, (ii) enhanced PW activity is seen almost simultaneously. This study shows that the recent SSW events had tropical associations. Further, favored occurrences of Equatorial Counter Electrojets (CEJs) with a quasi 16-day periodicity over Trivandrum (8.5oN, 76.5oE, 0.5oN diplat.) in association with the polar Stratospheric Sudden Warming (SSW) events are presented. It is seen that, the stratospheric temperature at 30 km over Trivandrum showed a sudden cooling prior to the SSW and the first bunch of CEJs occurred around this time. Stratospheric zonal mean zonal wind at 30 km exhibited a distinctly different pattern during the SSW period. These circula-tion changes are proposed to be conducive for the upward

  13. The polar Sudden Stratospheric Warming (SSW) and it's possible manifestations in the equatorial Mesosphere-Thermosphere-Ionosphere

    NASA Astrophysics Data System (ADS)

    Pant, Tarun; Vineeth, C.; Sridharan, R.

    In this study, the variations in daytime mesopause temperature and the Equatorial Electrojet over equator during Sudden Stratospheric Warming (SSW) events over high latitudes have been investigated. To reflect upon the stratospheric conditions NCEP-NCAR reanalysis data have also been used. This study indicates a possible dynamical coupling between the two regions through the planetary wave activity. The amplified wave signatures of quasi-16 day period are seen in the equatorial mesopause temperature and zonal mean polar stratospheric temperature (at 10 hPa) during the course of SSW. The possibility that the planetary waves over the polar stratosphere, which play an important role in the generation of SSW, could also have contribution from the tropics has been indicated through numerical simulations in the past [Dunkerton, 1981], but due to the paucity of global measurements it could not be established unequivocally. These simulations also indicated the presence of a zero-wind line whose real counterparts were not observed in the atmosphere. The NCEP-NCAR reanalysis of stratospheric wind and temperatures clearly shows that (i) a dynamical feature similar to the zero-wind line appears over the tropics 60 days prior to the major warming and progresses poleward and, (ii) enhanced PW activity is seen almost simultaneously. This study shows that the recent SSW events had tropical associations. Further, favored occurrences of Equatorial Counter Electrojets (CEJs) with a quasi 16-day periodicity over Trivandrum (8.5oN, 76.5oE, 0.5oN diplat.) in association with the polar Stratospheric Sudden Warming (SSW) events are presented. It is seen that, the stratospheric temperature at 30 km over Trivandrum showed a sudden cooling prior to the SSW and the first bunch of CEJs occurred around this time. Stratospheric zonal mean zonal wind at 30 km exhibited a distinctly different pattern during the SSW period. These circulation changes are proposed to be conducive for the upward

  14. Sandstream on the northeast Brazilian shelf

    NASA Astrophysics Data System (ADS)

    Vianna, Marcio L.; Solewicz, Reynaldo; Cabral, Alexandre P.; Testa, Viviane

    1991-06-01

    A preliminary characterization of seabed morphology and mapping of algal patches within a sandstream on the northeast Brazilian continental shelf off Cape Calcanhar (where the South American coast turns sharply to the west) is presented. The study area (30 km × 30 km) is swept by unidirectional, wind-driven, tidally rectified currents, under the influence of the North Brazil Current. The study was made by use of Landsat Thematic Mapper (TM) data of the seafloor down to 40 m depth, digital bathymetric data from smooth sheets furnished by the Brazilian Navy, echo-sounder profiling and underwater surveying by SCUBA diving. A mesoscale shore-parallel natural zonation of the sandstream was observable on the TM-images: (a) an inner zone dominated by sediment resuspension caused by wave-driven turbulence and tidal currents; (b) an intermediate zone dominated by sand ribbons and other longitudinal bedforms; (c) an outer zone dominated by large-scale sand waves (underwater sand dunes) limited offshore by shore-parallel sandbanks. Image-assisted in situ work, carried out on the latter zone, gave the following results: (1) Morphology and sand composition—the asymmetric sand waves are made of medium quartz sand, with almost straight crests of lengths up to 4 km, heights between 3 and 7 m, and avalanche lee slopes of 30°; on the stoss sides we recorded the presence of ripples and absence of megaripples and benthic ecosystems; on interdune areas, benthic ecosystem patches dominated by foliaceous and calcareous algae were found.(2) Sediment transport—active bedload transport was observable only during the winter season, when the strongest wind-forced currents induce flow separation at the crests and avalanche streams on the lee slope. Within the interdune areas, under the influence of the lee vortices, benthic community data confirms no appreciable abrasion due to sand transport.(3) Biology—species composition and biomass estimates from the algal patches in the first

  15. Field Report on the iMUSH Active Source Seismic Experiment

    NASA Astrophysics Data System (ADS)

    Kiser, E.; Levander, A.; Schmandt, B.; Palomeras, I.; Harder, S. H.; Creager, K. C.; Vidale, J. E.; Malone, S. D.

    2014-12-01

    In the second half of July we completed the iMUSH active source seismic experiment, one component of the Imaging Magma Under Saint Helens project. A team of ~75 volunteers deployed 3500 seismographs to ~5920 locations on and around Mount St. Helens over the course of 3 weeks. This instrument deployment was accompanied by 23 shots distributed around the volcano. Instrumentation consisted of ~2550 Reftek 125A (Texan) seismographs with 4.5 Hz geophones, and 920 Nodal Seismic recorders with 10 Hz geophones. The shots were also recorded by the permanent stations of the Pacific Northwest Seismograph Network and 70 iMUSH broadband seismographs. Fifteen of the shots, 424 kg each, formed two rings around Mount Saint Helens at 15 km and 30 km radius from the summit. Eight of the shots, 828 kg each, were fired at distances of 50 to 80 km from MSH on NW-SE and NE-SW azimuths. The deployment geometry consisted of two lines oriented NW/SE and NE/SW, and three arrays. The offset of the lines ranged from 150 km to 190 km with an average spacing of 200 m. The first array was centered on the volcano with a radius of 30 km, and required both driving and hiking to deploy. Arrays two and three were set out with, and centered on, the NW/SE line. These arrays had a distance range from MSH of 30-75 km and an azimuth range of about 100 degrees. In addition to this large-scale deployment, we set out 7 beamforming arrays approximately collocated with iMUSH broadband seismographs, and above clusters of seismicity in the region. The aperture of these arrays was about 1 km with an instrument spacing of 100 m. The final deployment ended only days before the AGU abstract deadline, so we have not yet examined all of the data. However, the preliminary indications are that signal to noise is excellent: The shots, several of which registered on PNSN as ML>2.1, carried across the entire array, and were recorded as far away as Seattle and Corvallis on permanent stations. The array also recorded a

  16. Microbiological sampling of the atmosphere using a latex sounding balloon

    NASA Astrophysics Data System (ADS)

    Adkins, W. P.; Bryan, N.; Christner, B. C.; Guzik, T. G.; Stewart, M. F.; Giammanco, J. R.

    2010-12-01

    The occurrence of microbes in the atmosphere has been the subject of scientific inquiry since Louis Pasteur’s time; however, data on the nature and diversity of microbial life in the upper troposphere and stratosphere is very limited. To experimentally address this, we have designed, constructed, and field-tested a lightweight, autonomous system that can sample at high altitudes using a latex sounding balloon. An important aspect of our sampling protocol is the ability to decontaminate and assess the level of background contamination during laboratory and field handling. Our approach involves the parallel decontamination and monitoring of 3 identical payloads: (i) one that remains in the laboratory, (ii) a control on the flight string, and (iii) a payload that opens and samples airborne particles in the atmosphere. Comparative analysis of various sterilization methods indicated that ethylene oxide was most effective at decreasing the concentration of DNA-containing cells, decreasing background cellular contamination by 94%. In conjunction, germicidal ultraviolet light, sodium hypochlorite, and 70% ethanol were used to decrease the concentration of microbes associated with payload surfaces. Bioaerosol collection is achieved by impact sampling on a 3.5 mm^2 retention surface covered with a thin layer of sterile silicone grease as the payload travels through the atmosphere. Initial flights have been successful in recovering viable microorganisms present in parcels of air at altitudes of 3 km to 9 km. Microscopic analysis on the collected cell assemblages implied that ~70% of the cells were potentially viable, and aerobic heterotrophic bacteria were cultured and isolated from liquid and agar-solidified culture media. Future plans include increasing the sampling altitude up to ~30 km in a series of discrete steps, maintaining our background controls and connection to lower altitude measurements. The pressure, temperature, and radiation levels in Earth’s stratosphere

  17. Integrated seismic model of the crust and upper mantle of the Trans-European Suture zone between the Precambrian craton and Phanerozoic terranes in Central Europe

    NASA Astrophysics Data System (ADS)

    Wilde-Piórko, Monika; Świeczak, Marzena; Grad, Marek; Majdański, Mariusz

    2010-01-01

    The structure and evolution of the Trans-European Suture zone (TESZ), contact between Precambrian Europe to the northeast and Phanerozoic terranes to the southwest is one of the main tectonic questions in Europe. The knowledge of the crustal structure, lithosphere-asthenosphere boundary and mantle transition zone between two seismic discontinuities at depths "410" and "660" km, is one of the most important issues to understand the Earth's dynamics. To create a mantle model of the TESZ and surroundings we used different seismic data collected along the 950 km long POLONAISE'97 profile P4. Previous results of 2-D ray-tracing and P-wave travel time modelling and new results of P-wave travel time residuals methods and receiver function sections provide facts about the seismic structure from the surface down to 900 km depth. In the TESZ a large basin, about 125 km wide, is filled with sedimentary strata (Vp < 6.0 km s - 1 ) to about 20 km depth. This basin is asymmetric with its northeast margin being most abrupt. The crystalline crust under this basin is only about 20 km thick today indicating that the lithosphere of Baltica was either thinned drastically or terminated along the northeast margin of the basin. The East European craton (EEC) has a ~ 45 km thick three-layered crust. The crust of the accreted terranes to the southwest is relatively thin (~ 30 km) and similar to that found in other non-cratonal areas of Western Europe. The lower crust is relatively fast (Vp > 7.0 km s - 1 ) along most of the P4 profile. However, lower values to the southwest may indicate the termination of Baltica. High velocity (~ 8.35 km s - 1 ) uppermost mantle lies beneath the Avalonia/Variscan terranes, and may be due to rifting and/or subduction. The seismic lithosphere thickness for the EEC is about 200 km, while it is only 90 km in the Palaeozoic platform (PP). The mantle transition zone is shallower and about 30 km thicker under the EEC, which could be due to thermal conditions

  18. Subtidal circulation on the Scotian Shelf: Assessing the hindcast skill of a linear, barotropic model

    NASA Astrophysics Data System (ADS)

    Thompson, Keith R.; Sheng, Jinyu

    1997-11-01

    Currents measured during the winter of 1985-1986 by four moorings on the inner Scotian Shelf are used to assess the hindcast skill of a three-dimensional circulation model forced by local wind stress and coastal sea level. The model is linear and barotropic. The integration scheme is based on the modification of the Galerkin spectral method proposed recently by Sheng and Thompson [1993]. The skill of the model is measured by the variance of the hindcast errors divided by the variance of the observations (henceforth γ2). The model is most effective within 30 km of shore (0.51<=γ2<=0.66). At the mooring in the Nova Scotia Current, a surface intensified southwestward jet with its center approximately 50 km from shore, the model fails to capture the bulk of the variance at current meters within 70 m of the surface (0.81<=γ2<=0.87). The skill of the model is lowest at the mooring 65 km from shore (0.92<=γ2<=0.94). To put these measures of skill into perspective, the currents are hindcast using a linear statistical model with the same inputs as the circulation model. The statistical model is optimal in the sense no other linear model with these inputs can achieve a lower hindcast error variance. For half of the current meters within 30 km of shore and two in the Nova Scotia Current the skill of the circulation model is not significantly lower than that of the statistical model. The largest discrepancies in the skill of the two models are found at the offshore mooring. We show that the suboptimal performance of the circulation model is due in part to the assumption of a spatially uniform wind field. We speculate that another contributing factor is the assumed form of the sea level profile along the open boundary that is upstream in the sense of coastal trapped wave propagation. Finally, the statistical model is used to estimate the increase in skill of the circulation model that may result from the assimilation of hydrographic data and additional coastal sea levels.

  19. Estimating Moho depth utilizing S-wave receiver functions

    NASA Astrophysics Data System (ADS)

    Ceylan, S.; Rychert, C.; Harmon, N.

    2014-12-01

    H-k stacking method [Zhu and Kanamori, 2000] is a widely used grid search technique for estimating the Moho depth (H) and Vp/Vs (k) beneath a given station. The H-k surface reaches a maximum when the optimum H and k values are used, which is assumed to be the average crustal structure beneath the seismic station. In general, the method is employed in conjunction with P-wave receiver functions. Here, we investigate the usability of H-k stacking method with S-to-P (Sp) conversions and S-wave reverberations within the crust, employing an extended multi-taper deconvolution. We apply the method to southern California, using data recorded between 1990-2011. We compare results with those of prior studies that used P-to-S (Ps) conversions [Zhu and Kanamori, 2000; Yan and Clayton, 2007], applying a smoothing length of 0.5 degrees to reflect lateral Sp sensitivity. P-waves have better potential to resolve lateral variations in Moho depth owing to the higher frequency content and the geometry of Ps ray path. Our results from Sp conversions are in broad agreement with those from Ps, affirming that S-wave receiver functions can be used in conjunction with the H-k stacking method. Consistent with the P-wave receiver function results, crust is thinner beneath the central Transverse Range (30 km) with respect to eastern Transverse Range (33 km) and Peninsular Region (35 km). Our Moho depth observations (35 km) are more compatible with those of Yan and Clayton [2007] (~35 km) than Zhu and Kanamori [2000] (~30 km) beneath Sierra Nevada, most probably due to a larger data set this study and Yan and Clayton [2007] use. Also, results from this study are deeper than those from Ps for the Salton Trough (30-35 km vs. 25 km). In this case, broad receiver function waveform characteristics suggest a more gradual impedance change across the Moho discontinuity and/or a multi-layered crust. We suggest that a combination of P- and S-wave receiver functions can yield more robust crustal thickness

  20. Imaging crust and mantle discontinuities across tectonic boundaries in North America with Sp receiver functions

    NASA Astrophysics Data System (ADS)

    Fischer, Karen M.; Hopper, Emily

    2015-04-01

    When broadband stations are spaced at ~70 km or less, as with the EarthScope Transportable Array in North America, common conversion point stacking of Sp receiver functions is capable of continuous three-dimensional imaging of velocity gradients at shallow mantle depths, provided that the gradients are localized over ~30 km or less. In the tectonically active western United States, Sp common conversion points stacks reveal a strong and coherent negative velocity gradient (velocity drop with increasing depth) that falls within the transition from high velocity lithosphere to low velocity asthenosphere seen in surface wave tomography. This negative velocity gradient is interpretable as the seismological lithosphere-asthenosphere boundary. Its depth varies significantly across certain tectonic boundaries at horizontal length scales of less than ~75 km, consistent with a rheologically strong mantle lithosphere in which strain can localize. When station spacing is sufficiently dense (~5 km) coherent imaging of discontinuities in the upper and lower crust is possible, even for Sp phases with dominant periods close to 10 s. With data from the 85 broadband stations of the SESAME array in the southeastern United States (an EarthScope Flexible Array experiment) and adjacent Transportable Array and permanent stations, common conversion point stacking of Sp phases resolves strong velocity gradients in the upper and lower crust that are continuous over hundreds of horizontal kilometers. Across the Suwannee suture (the northern edge of the Gondwanan or peri-Gondwanan Suwannee lithosphere that accreted to Laurentia in the last stages of the Appalachian orogeny) a strong positive velocity discontinuity dips southward from the surface expression of the suture to depths of 25-30 km. Modeling with common conversion point stacks of synthetic Sp phases demonstrates that Sp data can resolve the dipping discontinuity, despite the presence of sediment-filled Mesozoic rift basins and

  1. Convection-driven compaction as the source of Enceladus' enigmatic long wavelength topography

    NASA Astrophysics Data System (ADS)

    Besserer, J.; Nimmo, F.; Pappalardo, R. T.

    2012-12-01

    The long wavelength topography of Enceladus shows depressions about 0.8-1.5 km in depth and 90-175 km wide [1,2]. One possible mechanism to cause this topography is spatial variations in heat flux, leading to variable amounts of compaction of an initially porous ice shell [1]. Here, we show that the heat flux variations associated with convection (e.g., [3]) can quantitatively match the observed features. We model the evolution of a 20-to-30 km thick conductive, initially porous stagnant lid. Heat conduction is modeled using a 1D-finite volume approach, in which thermal conductivity varies with porosity [4]. Porosity evolution due to viscous flow is modeled using the method of [5], with an Arrhenius law and appropriate rheological parameters for ice I, resulting in a feedback on the thermal evolution (e.g., [6]). The surface is kept at constant temperature and a constant (convective) heat flux is prescribed at the base of the conductive layer. Models are run during a period of 100 Myr and the resulting thermal and porosity equilibrium structures are compared, for a range of initial porosity and reference viscosity values. We vary the stagnant lid thickness from 20 to 30 km, as suggested by numerical models [3]. This variation in lid thickness results in an elevation difference of ~0.9 km for an initial porosity of 20 %. This result is not very sensitive to reference viscosity assumed but depends significantly on the initial porosity. For instance, a value of 10 % yields a topography variation of ~0.45 km, which becomes ~1.3 km for 30 % initial porosity. Evolution during a much longer period, e.g. 1 Gyr, results in a slight decrease of topography: ~1.2 km (initial porosity of 30 %) to ~0.41 km (initial porosity of 10 %). This mechanism provides a simple way to explain the wavelength and amplitude of the observed topographic features. Such a mechanism works best in low-gravity environments that are capable of sustaining thermal convection; Enceladus and (perhaps

  2. Stratospheric Age Spectra and Mean Ages from In Situ Observations of Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Andrews, Arlyn E.; Boering, Kristie A.; Daube, Bruce C., Jr.; Wofsy, Steven C.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    In situ observations of CO2 obtained from 1992 through 2000 using the NASA ER-2 aircraft and high-altitude balloons show that seasonal and interannual variations in CO2 mixing ratios propagate from the troposphere into the lower stratosphere via the tropical tropopause, along with the long-term trend due to fossil fuel combustion. These signals spread laterally and vertically, providing detailed quantitative information about the transport history of sampled air. We have used these data to derive age spectra and mean ages that can be compared with results from models of the stratospheric circulation. For an air parcel at a point in the stratosphere, the age spectrum is defined as the probability distribution function for transit times from the tropical tropopause for each fluid element comprising the parcel. The mean age is the average transit time, corresponding to the first moment of the age spectrum. Age spectra have been derived for altitudes below approximately 20 km for the tropics and for northern midlatitudes where there is sufficient data and where the amplitudes of the seasonal and interannual oscillations in CO2 mixing ratios are large enough to be detected. Tropical age spectra are narrow, with seasonal variation indicating faster ascent during northern winter, consistent with a circulation driven by breaking of extratropical waves. The midlatitude CO2 data are consistent with bimodal age spectra, which could result from a subtropical "barrier" to horizontal exchange over a substantial altitude region. Seasonally resolved mean ages are available with nearly pole-to-pole coverage below 20 km and in the tropics and at middle and high northern latitudes up to the maximum altitude reached by the balloons (approximately 30 km). At ER-2 altitudes, steep meridional gradients in mean age are observed in the subtropics. Between 20 and 30 km, midlatitude air is approximately 2 years older than tropical air at the same altitude. The oldest air sampled was in the

  3. The Lithospheric Structure of Ordos, China: Evidence from Refined Virtual Deep Seismic Sounding (VDSS)

    NASA Astrophysics Data System (ADS)

    Liu, T.; TAO, K.; Klemperer, S. L.; Ning, J.

    2014-12-01

    The Archean North China Craton has undergone significant reactivation since the Mesozoic in its eastern part, the East North China Craton (ENCC). In contrast, the West North China Craton (WNCC), which is largely composed of the Ordos Block, has maintained its stability as a cratonic block. Ordos, as expected for a craton, has a much thicker lithosphere (~200 km) than ENCC (~80 km), and traditional receiver functions (RF) suggested average crustal thickness of ~40 km beneath Ordos, albeit 10 km thicker than the ~30km beneath the ENCC. In contrast, VDSS applied to an E-W linear Peking University seismic array across middle Ordos (latitude 37.5°N) found the Moho much deeper at ~60 km (Yu et al., EPSL, 2012). To better understand the lithospheric structure of Ordos, we applied VDSS to two E-W linear Chinese Academy of Sciences arrays across north (39.5°N) and south (36°N) Ordos. We applied wave mode-separation and deconvolution techniques that significantly removed the influence of the source wavelet and improved the resolution in VDSS. We show that beneath the southern array the Moho (from VDSS) is generally flat within Ordos at ~51 km, but rapidly shallows eastward to ~28 km from 110.5°E to 112.5°E, very similar to the Moho shape of the middle profile. The rapid change in Moho depth on the two profiles may be due to the influence of the Shanxi Graben from 36°N to 37.5°N. Beneath the northern array a continuously west-dipping Moho is found from ~26 km at 112°E to ~45km at 107.5°E. Our VDSS result for both the southern and northern arrays is clearly different from the conventional RF results given by Zheng et al. (JGR, 2012), which show an almost flat Moho at ~40 km with a trough at 110.5°E beneath the northern array and a Moho gently dipping westward from ~30 km at 114°E to ~40 km at 108°E beneath the southern array. The Moho found by RF is the interface with the largest S velocity contrast within the lithosphere, whereas the Moho found by VDSS is the

  4. Seismogenic ';trapdoors' during magma intrusion at Eyjafjallajökull volcano, Iceland

    NASA Astrophysics Data System (ADS)

    White, R. S.; Tarasewicz, J.; Brandsdottir, B.; Schonnman, C.

    2013-12-01

    Relocated earthquake hypocentres for >1000 microearthquakes that occurred prior to and during the 2010 fissure and summit eruptions of Eyjafjallajökull volcano in Iceland map out magma conduits from the upper mantle (30 km depth) to the surface. During the two weeks prior to the first, flank eruption, hypocentre locations lie predominantly in horizontally separated clusters at 3-4 km below sea level. They represent the filling with magma of an inflating sill beneath the eastern flank of the volcano, from which feeder dykes propagated laterally and vertically toward the flank eruption site three days prior to the eruption onset. The majority of events within some clusters of up to >100 earthquakes exhibit similar waveforms and identical patterns of P-wave first-motion polarities recorded across the monitoring network. In the clearest example, 104 out of 105 events in a single cluster appear to have the same source mechanism based on P-wave first-motion polarities and waveform similarity. These observations suggest that the clusters of similar events may comprise many earthquakes generated by source processes that have the same orientation of failure, perhaps even on the same rupture plane, in fixed locations that are repeatedly active. The epicentral clustering and similarity of source mechanisms suggest that much of the seismicity was generated at approximately static constrictions to magma flow in an inflating sill. These constrictions may act as a form of pressure valve or ';trapdoor' in the country rock, which ruptures when the melt pressure exceeds a critical level, then reseals after a pulse of melt has passed through. We infer that the magmatic intrusion causing the seismicity was likely to be a laterally inflating sill at 3-4 km depth, with seismogenic pinch-points occurring between aseismic compartments of the sill, or between adjacent magma lobes as they inflate. A second eruption followed from the summit, 8 km west of the first eruption site. During the

  5. S-wave triggering of tremor beneath the Parkfield, California, section of the San Andreas fault by the 2011 Tohoku, Japan earthquake: observations and theory

    USGS Publications Warehouse

    Hill, David P.; Peng, Zhigang; Shelly, David R.; Aiken, Chastity

    2013-01-01

    The dynamic stresses that are associated with the energetic seismic waves generated by the Mw 9.0 Tohoku earthquake off the northeast coast of Japan triggered bursts of tectonic tremor beneath the Parkfield section of the San Andreas fault (SAF) at an epicentral distance of ∼8200  km. The onset of tremor begins midway through the ∼100‐s‐period S‐wave arrival, with a minor burst coinciding with the SHSH arrival, as recorded on the nearby broadband seismic station PKD. A more pronounced burst coincides with the Love arrival, followed by a series of impulsive tremor bursts apparently modulated by the 20‐ to 30‐s‐period Rayleigh wave. The triggered tremor was located at depths between 20 and 30 km beneath the surface trace of the fault, with the burst coincident with the S wave centered beneath the fault 30 km northwest of Parkfield. Most of the subsequent activity, including the tremor coincident with the SHSH arrival, was concentrated beneath a stretch of the fault extending from 10 to 40 km southeast of Parkfield. The seismic waves from the Tohoku epicenter form a horizontal incidence angle of ∼14°, with respect to the local strike of the SAF. Computed peak dynamic Coulomb stresses on the fault at tremor depths are in the 0.7–10 kPa range. The apparent modulation of tremor bursts by the small, strike‐parallel Rayleigh‐wave stresses (∼0.7  kPa) is likely enabled by pore pressure variations driven by the Rayleigh‐wave dilatational stress. These results are consistent with the strike‐parallel dynamic stresses (δτs) associated with the S, SHSH, and surface‐wave phases triggering small increments of dextral slip on the fault with a low friction (μ∼0.2). The vertical dynamic stresses δτd do not trigger tremor with vertical or oblique slip under this simple Coulomb failure model.

  6. P wave attenuation structure below the Tokyo Metropolitan area

    NASA Astrophysics Data System (ADS)

    Panayotopoulos, Y.; Sakai, S.; Nakagawa, S.; Kasahara, K.; Hirata, N.; Aketagawa, T.; Kimura, H.; Lee, C.

    2010-12-01

    The material properties of the complex subduction zone beneath the Tokyo Metropolitan can be estimated by the seismic attenuation Q-1 of seismic waves observed at local seismic stations. The attenuation of seismic waves is represented by the t* attenuation operator that can be estimated by fitting the observed P wave amplitude spectrum to a theoretical spectrum using an ω2 source model. The waveform data used in this study are recorded at the dense seismic array of the Metropolitan Seismic Observation network (MeSO-net). The station network is distributed on five lines with an average spacing of 3 km and in an area with a spacing of 5 km in the central part of Kanto plane. The MeSO-net stations are equipped with a three-component accelerometer at a bottom of a 20-m-deep borehole, signals from which are digitized at a sampling rate of 200 Hz with a dynamic range of 135 dB.The waveforms of 141 earthquakes observed at 226 stations were selected from the Japan Meteorological Agency (JMA) unified earthquake list from January 1st 2010 to August 4th 2010. Only high-quality amplitude spectra of earthquakes with M > 3 were used for the estimation of reliable attenuation parameters. The acceleration waveforms were integrated twice to yield the corresponding displacement vectors, applying a high pass filter to remove the effect of the low-frequency background noise. Taking into account that the majority of the events occurred at depth greater than 30 km a search window of 5 sec starting 1 sec before the P wave arrival was implemented for the creation of the dataset. The t* values were estimated from the amplitude spectra of approximately 33800 P wave waveforms conducting a fast Fourier transform analysis. The Q values for the Tokyo Metropolitan area estimate by this study range from 100 to 500 in the upper 30 km of the crust. A site effect on the attenuation near stations inside a densely populated area is also a possible reason for the large Q variations observed.

  7. Formation and evolution of the Solander Basin, southwestern South Island, New Zealand, controlled by a major fault in continental crust and upper mantle

    NASA Astrophysics Data System (ADS)

    Sutherland, Rupert; Melhuish, Anne

    2000-02-01

    Seismic reflection and refraction data from the Solander Basin, southern New Zealand, show that its structural evolution has been controlled by a major fault, named here the Tauru Fault, that cuts the entire crust and splays into a diffuse zone in the upper mantle. The tectonic setting of the Solander Basin has evolved from Eocene-Oligocene extension and transtension to Miocene-Quaternary transpression and subduction. The Tauru Fault is 100 km east of the active Puysegur subduction zone thrust and is part of the overriding plate. On the basis of lower crustal reflectivity, the base of the crust beneath the adjacent Stewart Island shelf is at ˜30 km depth (˜9 s two-way time (TWT)), and rises to ˜20 km (˜8 s TWT) beneath the Solander Basin. This is consistent with gravity data. Prominent dipping reflections show that the Tauru Fault can be traced to ˜30 km depth (˜12 s TWT), where it merges with a zone of subhorizontal reflectors in the upper mantle. The Tauru Fault dips ˜30° northeast and appears to offset the Moho in a reverse sense. Stratigraphic relationships show that the Tauru Fault was active as a normal fault during Eocene extension, when Solander Basin crust was thinned and ocean crust was generated farther south in the Solander Trough. It has been reactivated as a reverse fault during at least two phases of Miocene-Quaternary compression and is still active. The strike of the Tauru Fault, which is parallel to Paleozoic-Mesozoic structures and was poorly oriented for the known Eocene extension direction, strongly suggests that it formed prior to Eocene time. The Tauru Fault significantly influenced the geometry of Eocene basin formation, producing a strongly asymmetric basin dominated by east dipping normal faults, with a single eastern boundary fault. Our data demonstrate that Miocene-Quaternary simple shear associated with the Tauru Fault cuts the whole crust and continues into the upper mantle. We conclude that variations in strength of the

  8. Comparison of Marine Boundary Layer Cloud Properties From CERES-MODIS Edition 4 and DOE ARM AMF Measurements at the Azores

    NASA Astrophysics Data System (ADS)

    Dong, X.; Xi, B.; Minnis, P.; Sun-Mack, S.

    2014-12-01

    Marine Boundary Layer (MBL) cloud properties derived for the NASA CERES Project using Terra and Aqua MODIS data are compared with observations taken at DOE ARM Mobile Facility at the Azores site from Jun. 2009 to Dec. 2010. Cloud properties derived from ARM ground-based observations were averaged over a 1-hour interval centered at the satellite overpass time, while the CERES-MODIS (CM) results were averaged within a 30×30 km2 grid box centered over the Azores site. A total of 63 daytime and 92 nighttime single-layered overcast MBL cloud cases were selected from 19 months of ARM radar-lidar and satellite observations. The CM cloud-top/base heights (Htop/Hbase) were determined from cloud-top/base temperatures (Ttop/Tbase) using a regional boundary-layer lapse rate method. For daytime comparisons, the CM-derived Htop (Hbase), on average, is 0.063 km (0.068 km) higher (lower) than its ARM radar-lidar observed counterpart, and the CM-derived Ttop and Tbase are 0.9 K less and 2.5 K greater than the surface values with high correlations (R2=0.82 and 0.84, respectively). In general, the cloud-top comparisons agree better than cloud-base comparisons because the CM Tbase and Hbase are secondary product determined from Ttop and Htop. No significant day-night difference was found in the analyses. The comparisons of microphysical properties reveal that, when averaged over a 30x30 km2 area, the CM-retrieved cloud-droplet effective radius (re) is 1.3 µm larger than that from the ARM retrievals (12.8 µm). While the CM-retrieved cloud liquid water path (LWP) is 13.5 gm-2 less than its ARM counterpart (114.2 gm-2) due to its small optical depth (τ, 9.6 vs. 13.7). The differences are reduced by 50% when the CM averages are computed only using the MODIS pixel nearest the AMF site. Using effective radius retrieved at 2.1-µm channel to calculate LWP can reduce the difference between the CM and ARM from -13.7 to 2.1 gm-2. The 10% differences between the ARM and CM LWP and re

  9. Bathymetric Signatures of Oceanic Detachment Faulting and Potential Ultramafic Lithologies at Outcrop or in the Shallow Subseafloor

    NASA Astrophysics Data System (ADS)

    Cann, J. R.; Smith, D. K.; Escartin, J.; Schouten, H.

    2008-12-01

    For ten years, domal bathymetric features capped by corrugated and striated surfaces have been recognized as exposures of oceanic detachment faults, and hence potentially as exposures of plutonic rocks from lower crust or upper mantle. Associated with these domes are other bathymetric features that indicate the presence of detachment faulting. Taken together these bathymetric signatures allow the mapping of large areas of detachment faulting at slow and intermediate spreading ridges, both at the axis and away from it. These features are: 1. Smooth elevated domes corrugated parallel to the spreading direction, typically 10-30 km wide parallel to the axis; 2. Linear ridges with outward-facing slopes steeper than 20°, running parallel to the spreading axis, typically 10-30 km long; 3. Deep basins with steep sides and relatively flat floors, typically 10-20 km long parallel to the spreading axis and 5-10 km wide. This characteristic bathymetric association arises from the rolling over of long-lived detachment faults as they spread away from the axis. The faults dip steeply close to their origin at a few kilometers depth near the spreading axis, and rotate to shallow dips as they continue to evolve, with associated footwall flexure and rotation of rider blocks carried on the fault surface. The outward slopes of the linear ridges can be shown to be rotated volcanic seafloor transported from the median valley floor. The basins may be formed by the footwall flexure, and may be exposures of the detachment surface. Critical in this analysis is that the corrugated domes are not the only sites of detachment faulting, but are the places where higher parts of much more extensive detachment faults happen to be exposed. The fault plane rises and falls along axis, and in some places is covered by rider blocks, while in others it is exposed at the sea floor. We use this association to search for evidence for detachment faulting in existing surveys, identifying for example an area

  10. High Resolution Seismic Reflection Imaging of the Southern Whidbey Island fault, Northwest Washington State

    NASA Astrophysics Data System (ADS)

    Pape, K. M.; Liberty, L. M.; Pratt, T. L.

    2006-12-01

    The Southern Whidbey Island fault (SWIF) is an active fault between the Seattle and Everett Basins in northwest Washington State. Marine seismic and geologic data characterize the SWIF as sub-parallel, northwest trending reverse faults that may extend over a 100 km distance and may be capable of producing M 7 or greater earthquakes. We acquired two land-based seismic transects crossing LIDAR and magnetic lineaments associated with the SWIF near Woodinville, WA, to relate surface scarps to subsurface structures and to characterize deformation in the upper 0.5 km of strata. Nearby borehole data place Pleistocene and younger deposits at depths less than 0.2 km, with Tertiary and older strata identified below. The 2 km, north-south Crystal Lake transect crosses the surface locations of LIDAR and magnetic lineaments and shows reverse faulting that offsets Tertiary and younger strata in a zone that extends more than 1.25 km. In contrast, we interpret relatively undeformed, flat lying Tertiary strata at depths of 0.1 to 0.2 km south of the observed surface lineaments. In the 3 km, east-west Woodinville transect, we identify reverse faulting and folding that forms a small 0.75 km-wide graben within a broader deformation zone. These anomalies are on strike with the LIDAR and magnetic lineaments identified near Crystal Lake. The presence of a small graben in the SWIF is consistent with models that hypothesize strike-slip motion on the fault system, with curvature of adjacent fault strands forming a small pull-apart basin. Our observations suggest that other magnetic lineaments in the region also are likely associated with fault strands. We acquired three additional transects upwards of 30 km southeast of Woodinville to determine whether the SWIF extends beyond surface lineaments and potentially merging with the Seattle Fault. Our preliminary analysis shows faulted Tertiary and younger strata on these profiles. If the observed fault strands on these transects are related to

  11. The Accidental Tide Gauge: A Case Study from Kachemak Bay, Alaska

    NASA Astrophysics Data System (ADS)

    Larson, K. M.; Ray, R. D.; Nievinski, F. G.; Freymueller, J. T.

    2012-12-01

    It is well-known that GPS instruments can be used to measure local sea level. In most demonstrations of this method two antennas are deployed at a coastal site. A geodetic antenna - optimized for RHCP signals - is used in the traditional orientation and tracks the direct signal. The second antenna is optimized for reflected signals - which are primarily LHCP - and is pointed towards the ocean. The sea surface can then be estimated by analyzing the carrier phase data. While the data from the "up" antenna are dominated by the direct signal, the effects of signals reflected from the ocean are also present in its data. Thus in principle, one might be able to estimate sea level using only data from the up antenna. This is similar in concept to recent multipath studies where geodetic GPS installations are being used to measure soil moisture variations and snow depth. Observations of signal-to-noise (SNR) provide a simple observable to extract the frequencies needed to measure sea level. We have analyzed GPS SNR data for a one-year time period from a GPS installation in Peterson Bay, off Kachemak Bay. It is ~10 km from Homer, Alaska. The GPS antenna is located on a small island. It was installed to measure plate boundary deformation. Daily sea level variations can be more than 7 meters at this site. Tidal coefficients have been estimated for the one-year time period. These are compared with coefficients estimated from records from a traditional tide gauge operated by NOAA at Seldovia Harbor, ~30 km away, as well as older, less reliable tidal analyses for Homer, Bear Cove, and Kasitsna Bay. Precision and accuracy of the GPS tide gauge will be discussed. The GPS and Seldovia estimates of M2 coefficients agree to better than 2%, and much of this residual can be attributed to true differences in the tide over 30 km as it propagates up Kachemak Bay. Of course the GPS data can also be used to measure the geocentric height of the GPS antenna, thus providing an instrument for the

  12. Results From NICLAKES Survey of Active Faulting Beneath Lake Nicaragua, Central American Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Funk, J.; Mann, P.; McIntosh, K.; Wulf, S.; Dull, R.; Perez, P.; Strauch, W.

    2006-12-01

    In May of 2006 we used a chartered ferry boat to collect 520 km of seismic data, 886 km of 3.5 kHz subbottom profiler data, and 35 cores from Lake Nicaragua. The lake covers an area of 7700 km2 within the active Central American volcanic arc, forms the largest lake in Central America, ranks as the twentieth largest freshwater lake in the world, and has never been previously surveyed or cored in a systematic manner. Two large stratovolcanoes occupy the central part of the lake: Concepcion is presently active, Maderas was last active less than 2000 years ago. Four zones of active faulting and doming of the lake floor were mapped with seismic and 3.5 kHz subbottom profiling. Two of the zones consist of 3-5-km-wide, 20-30-km-long asymmetric rift structures that trend towards the inactive cone of Maderas Volcano in a radial manner. The northeastern rift forms a 20-27-m deep depression on the lake bottom that is controlled by a north-dipping normal fault. The southwestern rift forms a 25-35-m deep depression controlled by a northeast-dipping normal fault. Both depressions contain mound-like features inferred to be hydrothermal deposits. Two zones of active faulting are associated with the active Concepcion stratovolcano. A 600-m-wide and 6-km-long fault bounded horst block extends westward beneath the lake from a promontory on the west side of the volcano. Like the two radial rift features of Maderas, the horst points roughly towards the active caldera of Concepcion. A second north-south zone of active faulting, which also forms a high, extends off the north coast of Concepcion and corresponds to a localized zone of folding and faulting mapped by previous workers and inferred by them to have formed by gravitational spreading of the flank of the volcano. The close spatial relation of these faults to the two volcanic cones in the lake suggests that the mechanism for faulting is a result of either crustal movements related to magma intrusion or gravitational sliding and is

  13. Seismicity Patterns and Magmatic Processes in the Rwenzori Region, East-African Rift

    NASA Astrophysics Data System (ADS)

    Lindenfeld, M.; Rumpker, G.; Schmeling, H.; Wallner, H.

    2010-12-01

    The 5000m high Rwenzori Mountains are situated within the western branch of the East African Rift System (EARS), at the border between Uganda and the Democratic Republic of Congo. They represent a basement block located within the rift valley whose origin and relation to the evolution of the EARS are highly puzzling. During a recent seismological campaign we located more than 800 earthquakes per month with magnitudes ranging from 0.5 to 5.1. Vertical sections across the northern parts of the Rwenzoris show, that west of the mountains (towards the rift valley) the focal depths range from 10 to 20 km, whereas the hypocentres go as deep as 30 km on the eastern side. This is in good agreement with Moho-depths derived from receiver functions and implies that all of these events are located within the crust. However, about 30 km east of the northern mountain ridge we located a cluster of 7 events that exhibit an anomalous depth of about 60 km. We can confidently locate these earthquakes within the mantle lithosphere beneath the rift. The existence of earthquakes at this depth is enigmatic, especially within a rifting regime were one expects hot and weak material relatively close to the surface. We think that these events are possibly related to the evolution of the Rwenzori Mountains. A recent hypothesis to explain the extreme uplift of the Rwenzori Mountains is rift induced delamination (RID) of mantle lithosphere. Here we show that the RID-process is indeed capable of explaining the seismic energy release in the mantle. However, in view of the specific hypocentral location of the event cluster, magmatic impregnation processes associated with dyke propagation into the mantle lithosphere may be a more realistic cause for seismic radiation at the observed depth. Crustal earthquakes northeast of the Rwenzori area are relocated with a double-difference algorithm to improve the spatial resolution of seismicity pattern. Several event clusters in the vicinity of the Fort

  14. Subtidal currents over the central California slope: Evidence for offshore veering of the undercurrent and for direct, wind-driven slope currents

    USGS Publications Warehouse

    Noble, M.A.; Ramp, S.R.

    2000-01-01

    In February 1991, an array of six current-meter moorings was deployed for one year across the central California outer shelf and slope. The main line of the array extended 30 km offshore of the shelf break, out to water depths of 1400 m. A more sparsely-instrumented line, displaced 30 km to the northwest, extended 14 km offshore. Though shorter, the northern line spanned similar water depths because the gradient of the topography steepened in the northern region. A poleward flow pattern, typical of the California undercurrent, was seen across both lines in the array over most of the year. The poleward flow was surface intensified. In general, the portion of the undercurrent that crossed the southern line had larger amplitudes and penetrated more deeply into the water column than the portion that crossed the northern line. Transport over the year ranged from 0 to 2.5 Sverdrups (Sv) poleward across the southern line; 0 to 1 Sv poleward across the northern line. We suggest the difference in transport was caused by topographic constraints, which tended to force the poleward flow offshore of the northern measurement sites. The slope of the topography steepened too abruptly to allow the poleward flow to follow isobaths when currents were strong. When current velocities lessened, a more coherent flow pattern was seen across both lines in the array. In general, the poleward flow patterns in the undercurrent were not affected by local winds or by the local alongshore pressure gradient. Nor was a strong seasonal pattern evident. Rather unexpectedly, a small but statistically significant fraction of the current variance over the mid- and outer slope was driven by the surface wind stress. An alongshelf wind stress caused currents to flow along the slope, parallel to the wind field, down to depths of 400 m below the surface and out to distances of 2 Rossby radii past the shelf break. The transfer functions were weak, 3-4 cm/s per dyn cm-2, but comparable to wind-driven current

  15. Local network deployed around the Kozloduy NPP - a useful tool for seismological monitoring

    NASA Astrophysics Data System (ADS)

    Solakov, Dimcho; Simeonova, Stela; Dimitrova, Liliya; Slavcheva, Krasimira; Raykova, Plamena; Popova, Maria; Georgiev, Ivan

    2015-04-01

    Radiation risks may transcend national borders, and international cooperation serves to promote and enhance safety globally by exchanging experience and by improving capabilities to control hazards, to prevent accidents, to respond to emergencies and to mitigate any harmful consequences. International safety standards provide support for states in meeting their obligations under general principles of international law, such as those relating to environmental protection. Seismic safety is a key element of NPP safe operation. Safety and security measures have in common the aim of protecting human life and health and the environment. The Kozloduy NPP site is located in the stable part of the Moesian platform (area of about 50000 km2). From seismological point of view the Moesian platform is the most quite area on the territory of Bulgaria. There are neither historical nor instrumental earthquakes with M>4.5 occurred within the platform. The near region (area with radial extent of 30 km) of the NPP site is characterized with very low seismic activity. The strongest recorded quake is the 1987 earthquake МS=3.6, localized 22 km northwest of the Kozloduy NPP site on the territory of Romania. In line with international practice, the geological, geophysical and seismological characteristics of the region around the site have been investigated for the purpose of evaluating the seismic hazards at the NPP site. A local network (LSN) of sensitive seismographs having a recording capability for micro-earthquakes have been installed around Kozloduy NPP and operated since 1997. The operation and data processing, data interpretation, and reporting of the local micro-earthquake network are linked to the national seismic network (NOTSSI). A real-time data transfer from stations to National Data Center (in Sofia) was implemented using the VPN and MAN networks of the Bulgarian Telecommunication. Real-time and interactive data processing are performed by the Seismic Network Data

  16. Anchorage, AK

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Anchorage, Alaska and Cook Inlet are seen in this 30 by 30 km (19 by 19 miles) sub-image, acquired May 12, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). Orbiting at an altitude of 705 km (430 miles) on board NASA's Terra satellite, ASTER provides data at a resolution of 15 m (47 feet) and allows creation of this simulated natural color image. At the center of the image is the Ted Stevens Anchorage International Airport; in the upper right corner is Elmendorf Air Force Base. Dark green coniferous forests are seen in the northwest part of the image. A golf course, with its lush green fairways, is just south of the Air Force Base.

    The image covers an area of 30 by 30 km, was acquired May 12, 2000, and is located at 61.2 degrees north latitude and 149.9 degrees west longitude.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high-resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change. Examples of applications include monitoring glacial advances and

  17. Geomechanical models of impact cratering: Puchezh-Katunki structure

    NASA Technical Reports Server (NTRS)

    Ivanov, B. A.

    1992-01-01

    Impact cratering is a complex natural phenomenon that involves various physical and mechanical processes. Simulating these processes may be improved using the data obtained during the deep drilling at the central mound of the Puchezh-Katunki impact structure. A research deep drillhole (named Vorotilovskaya) has been drilled in the Puchezh-Katunki impact structure (European Russia, 57 deg 06 min N, 43 deg 35 min E). The age of the structure is estimated at about 180 to 200 m.y. The initial rim crater diameter is estimated at about 40 km. The central uplift is composed of large blocks of crystalline basement rocks. Preliminary study of the core shows that crystalline rocks are shock metamorphosed by shock pressure from 45 GPa near the surface to 15-20 GPa at a depth of about 5 km. The drill core allows the possibility of investigating many previously poorly studied cratering processes in the central part of the impact structure. As a first step one can use the estimates of energy for the homogeneous rock target. The diameter of the crater rim may be estimated as 40 km. The models elaborated earlier show that such a crater may be formed after collapse of a transient cavity with a radius of 10 km. The most probable range of impact velocities from 11.2 to 30 km/s may be inferred for the asteroidal impactor. For the density of a projectile of 2 g/cu cm the energy of the impact is estimated as 1E28 to 3E28 erg. In the case of vertical impact, the diameter of an asteroidal projectile is from 1.5 to 3 km for the velocity range from 11 to 30 km/s. For the most probable impact angle of 45 deg, the estimated diameter of an asteroid is slightly larger: from 2 to 4 km. Numerical simulation of the transient crater collapse has been done using several models of rock rheology during collapse. Results show that the column at the final position beneath the central mound is about 5 km in length. This value is close to the shock-pressure decay observed along the drill core. Further

  18. A new approach for tsunami early warning using tsunami observations in a source region

    NASA Astrophysics Data System (ADS)

    Tanioka, Y.

    2015-12-01

    After the 2011 devastating Tohoku tsunami, improvement of tsunami early warning system is one of key issues in Japan. Japanese government was decided to install 125 ocean bottom pressure sensors and seismometers with a cable system along the Japan and Kurile trench. Each sensor is separated by 30km. We should develop a new approach for real-time tsunami forecast using those newly available data combined with GNSS data or seismic data. A well-recognized problem to use tsunami data at pressure sensors on the top of tsunami source area is a fact that a large vertical coseismic deformation due to a large earthquake cannot be observed at those sensors. The sensors observe a tsunami wave when it starts to propagate. Because of that problem, GSNN data or seismic data are typically used to estimate the coseismic deformation for the tsunami numerical simulation. In this paper, we develop a new technique, which solve the problem. Our technique uses the observations at pressure sensors on the tsunami source area as an input to compute the tsunami directly. Actual tsunami heights at the sensors on the source area is unknown because the cosismic vertical deformation is unknown. However, we can observe directly the time derivative of tsunami heights at those sensors. Time derivatives of tsunami heights at each point are used as inputs to compute the tsunami height distribution in the calculated area. Then we can numerically compute a tsunami using a traditional finite difference technique from the tsunami height distribution computed. For numerical test, first, we compute the synthetic tsunamis using the fault model with 1 minute grid system. The computed tsunami waveforms at 15 minutes x 15 minutes grid points are used as the observed data for this new technique. Each observed point is separated by 15 minutes, about 30km. The result show that the accuracy of tsunami computation is good enough for tsunami forecast. Tsunami generation with a long duration, such as tsunami

  19. Rainfall estimates for hydrological models: Comparing rain gauge, radar and microwave link data as input for the Wageningen Lowland Runoff Simulator (WALRUS)

    NASA Astrophysics Data System (ADS)

    Brauer, Claudia; Overeem, Aart; Uijlenhoet, Remko

    2015-04-01

    Several rainfall measurement techniques are available for hydrological applications, each with its own spatial and temporal resolution. We investigated the effect of differences in rainfall estimates on discharge simulations in a lowland catchment by forcing a novel rainfall-runoff model (WALRUS) with rainfall data from gauges, radars and microwave links. The hydrological model used for this analysis is the recently developed Wageningen Lowland Runoff Simulator (WALRUS). WALRUS is a rainfall-runoff model accounting for hydrological processes relevant to areas with shallow groundwater (e.g. groundwater-surface water feedback). Here, we used WALRUS for case studies in the Hupsel Brook catchment. We used two automatic rain gauges with hourly resolution, located inside the catchment (the base run) and 30 km northeast. Operational (real-time) and climatological (gauge-adjusted) C-band radar products and country-wide rainfall maps derived from microwave link data from a cellular telecommunication network were also used. Discharges simulated with these different inputs were compared to observations. Traditionally, the precipitation research community places emphasis on quantifying spatial errors and uncertainty, but for hydrological applications, temporal errors and uncertainty should be quantified as well. Its memory makes the hydrologic system sensitive to missed or badly timed rainfall events, but also emphasizes the effect of a bias in rainfall estimates. Systematic underestimation of rainfall by the uncorrected operational radar product leads to very dry model states and an increasing underestimation of discharge. Using the rain gauge 30 km northeast of the catchment yields good results for climatological studies, but not for forecasting individual floods. Simulating discharge using the maps derived from microwave link data and the gauge-adjusted radar product yields good results for both events and climatological studies. This indicates that these products can be

  20. Preliminary Marine MT Results from the Anisotropy and Physics of the Pacific Lithosphere Experiment (APPLE)

    NASA Astrophysics Data System (ADS)

    Heinson, G.; Key, K.; Constable, S.; White, A.

    2002-12-01

    We present preliminary magnetotelluric (MT) and geomagnetic depth sounding (GDS) results from the Anisotropy and Physics of the Pacific Lithosphere Experiment (APPLE). APPLE included both controlled source EM and MT components in order to provide constraints on the depth and alignment of anisotropic conductivity structure in both the crust and upper mantle. A key goal of the MT component is to provide insights into electrical conduction mechanisms in the mantle, particularly the proposal that hydrogen dissolved in olivine enhances the conduction in the a axis direction. The main survey was located on 30 Ma old lithosphere, about 1000 km west of San Diego, USA. The core location consisted of two long period MT instruments (102 - 105 s), two broadband MT instruments (101-104 s) along with four long wire electric field receivers. Around the core eight additional instruments were positioned on a 30 km radius to provide constraints on lateral heterogeneities in conductivity structure that may masquerade as mantle anisotropy. Four long period instruments were also deployed along a transect from the core to the base of the continental slope to constrain the effect of the coast on the data. These were augmented with four broadband sites in 1500 m water on the continental shelf offshore San Diego and six broadband sites in 10-350 m water offshore Torrey Pines Beach, California. Processing the MT time series yielded impedance responses that are predominantly two dimensional (2D) with large splits between the two principal MT modes (up to a factor of 10 difference in apparent resistivity), with the greatest mode split and most significant GDS response occurring at sites nearest the continental margin. This suggests that much of this first order anisotropy in the MT response is due to the juxtaposition of the conductive ocean and the resistive continental crust, and indeed a 2D inversion that includes bathymetry of the coastline as fixed structure produces a model with

  1. Preliminary Seafloor Controlled Source EM Results From APPLE

    NASA Astrophysics Data System (ADS)

    Behrens, J. P.; MacGregor, L.; Constable, S.; Everett, M.

    2001-12-01

    Certain events in the life cycle of oceanic lithosphere are dominantly two-dimensional. These include formation of crust at axial spreading centers and deformation at the lithosphere - asthenosphere boundary. These processes may result in an electrically anisotropic oceanic lithosphere by creating conductive pathways in preferred orientations. Controlled Source Electromagnetic (CSEM) soundings and Magnetotelluric (MT) soundings were made during the Anisotropy and Physics of the Pacific Lithosphere Experiment (APPLE), carried out in February/March 2001 approximately 600 km west of San Diego, California. Twenty seafloor electromagnetic field sensors were deployed: 4 long-wire CSEM recorders with 200 m electrode offsets, 6 high-frequency MT/CSEM recorders with two orthogonal 10 m offset electrodes and two orthogonal induction coil magnetometers, and 10 low-frequency MT recorders with a three-component fluxgate magnetometer and two orthogonal 10 m electric dipoles, 5 of which also recorded CSEM data. Every instrument was recovered, with data, during this primary cruise and a follow-up recovery cruise for the long-period instruments in August 2001. The deep-towed EM transmitter (DASI) was a 100 m horizontal electric dipole, which was towed in a 30 km radius circle around a central core of recorders. A radial tow was also performed. DASI transmitted a 4 Hz square wave throughout the CSEM phase of the experiment. Initial processing of the CSEM data reveals evidence of crustal anisotropy. In particular, transmitted electromagnetic energy is attenuated more strongly when propagating from west to east than from north to south. The difference in attenuation is about a factor of two, at a range of 30 km and a frequency of 4Hz. This confirms earlier results from the PEGASUS experiment, which proposed that oceanic lower crust and upper mantle with east-west trending lineaments of increased conductivity will exhibit greater attenuation of electric fields in the east

  2. Horizontal variability of aerosol optical properties observed during the ARCTAS airborne experiment

    NASA Astrophysics Data System (ADS)

    Shinozuka, Y.; Redemann, J.; Russell, P. B.; Livingston, J. M.; Clarke, A. D.; Podolske, J. R.

    2010-12-01

    The properties of tropospheric aerosol and gas vary within a satellite grid cell and between ground-based instruments. This hinders comparison between satellite and suborbital measurements of different spatial scales as well as their applications to climate and air quality studies. This paper quantifies the realistic range of the variability in aerosol optical depth (AOD), its Angstrom exponent, in-situ extinction coefficient and carbon monoxide mixing ratio over horizontal distances of 1-30 km, using measurements from the ARCTAS airborne experiment. The Canada phase in June and July 2008, in which smoke from local forest fires was sampled, likely represents the most heterogeneous of the ambient aerosol environments common over the globe. The relative standard deviation (stdrel) of AOD measured with the 14-channel Ames Airborne Tracking Sunphotometer (AATS-14) has median 19.4% (at 499 nm) among thousands of horizontal 20 km segments. For 6 km segments the analogous median is 9.1%. Another measure of horizontal variability, the autocorrelation (r) of AOD499 across 20 km and 6 km segments is 0.37 and 0.71, respectively. In contrast, the Alaska phase in April 2008, which sampled particles transported from Asia, is presumably among the most homogeneous environments. The median stdrel is 3.0% and r is 0.90, both over 30 km, only slightly different from those for 1 km (stdrel=0.4% and r=1.00). r in the Canada phase is ~0.2 less for in situ extinction coefficient (from a nephelometer and a particle soot absorption photometer) than for the AOD. It is ~0.1 less than for the carbon monoxide mixing ratio. The trends of horizontal variability with distance and aerosol environment are different for the wavelength dependence and the humidity response of light scattering. We discuss challenges in estimating aerosol optical properties, particle size and chemical composition from measurements at a distant location. The statistical parameters thus help interpret existing remote

  3. Seismic Attenuation, Temperature, H20, Mantle Melting and Rock Uplift, Central North Island New Zealand

    NASA Astrophysics Data System (ADS)

    Salmon, M.; Savage, M.; Stern, T.

    2005-12-01

    Back-arc basins of the western Pacific are elevated some 1-2 km above the adjacent oceanic floor. Where oceanic back-arc basins propagate into continental lithosphere we also see an uplift signal, which can be mapped and evaluated with geological methods. Trying to understand the driving force for this uplift requires seismological methods to quantify temperatures, and therefore buoyancy, in the upper mantle. New Zealand's North Island is one such place where the back-arc basin has propagated into continental lithosphere. Geological records show that the North Island has undergone up to 2.5 km of broad wavelength rock uplift since 5 Ma. We use earthquake data to map variations in seismic attenuation (Qp-1) beneath the North Island. Results are used to determine some constraints on the effects of temperature, water and melt on buoyancy in the mantle wedge above the subduction zone. A region of high attenuation extending to depths of ~140 km correlates, spatially, with the region of back-arc extension, volcanism and high heat flow (Central Volcanic Region or CVR). In this region the path-averaged Qp-1 for frequencies from 1-15Hz is 4.0×10-3±0.3×10-3 and shows little variation with depth. West of the CVR, the north-western North Island shows a decrease in attenuation but Qp-1 remains slightly elevated (path-averaged Qp-1 1.4×10-3±0.2×10-3). Here attenuation increases with depth until it reaches similar values as the CVR mantle at approximately 80 km. We use Qp values to calculate temperatures at 30 km and 80 km depth below these two regions. Temperatures at 30 km below the CVR are elevated to just above the melting temperature (1.02 Tm) while to the west temperatures are just below the solidus (~0.95 Tm). At 80 km depth attenuation indicates temperatures for both regions are just above the solidus. To reconcile temperatures calculated from heat flow measurements in the north-western North Island with those calculated from attenuation, melting temperatures must

  4. Fault segmentation and seismic potential of the Median Tectonic Line in Shikoku, Japan

    NASA Astrophysics Data System (ADS)

    Ikeda, M.; Ikeda, M.; Zhao, D.; Ohno, Y.

    2001-12-01

    The Median Tectonic Line (MTL) is one of the most active fault system in Japan, which is an east-west trending, 190 km-long fault system and consists of several rupture segments in Shikoku. A long active fault system such as the MTL may not rupture along its entire length in a single earthquake but instead consists of multiple seismic segments that rupture independently of one another. Dominant factors controlling the dynamic behavior of the MTL may be the structure and processes in the deep crust or even down to the uppermost mantle, hence we need to consider a segmentation model taking into account the heterogeneous structure of the crust and upper mantle. We conducted seismic tomography inversions to estimate the crustal structure beneath the MTL in Shikoku. We collected 83875 P and 34106 S wave arrival times from 4374 local earthquakes that occurred from 1985 to 1993 from the Japan University Network Earthquake Catalog (EPDC, 1997). We used the tomographic method of Zhao et al. (1992). A 3-D grid net was set up in the study area with a grid spacing of about 30 km in the horizontal direction and 10-20 km in depth. Strong heterogeneities are revealed in the crust and uppermost mantle beneath the MTL in Shikoku. A prominent feature of the obtained tomographic results is that the three segments proposed by Goto et al.(2001) exhibit different velocity patterns. A prominent low-V zone is visible at depths of 15-30 km under the Central-East Shikoku segment. As the low-V zones may represent weak sections of the fault zone and it may influence the generation of large crustal earthquakes (e.g., Zhao et al., 2000), this feature may indicate that fault activity is different in the three segments of MTL. GPS observations for the MTL in eastern Shikoku indicate that the upper crust (0-15 km depths) of the MTL locks and steady slip occurs in the lower crust (Tabei et al., 2000). This steady slip zone coincides with the low-V zone revealed by our tomographic imaging in the

  5. Iterative de-convolution of the local waveforms: Characterization of the seismic sources in Kachchh, India

    NASA Astrophysics Data System (ADS)

    Mandal, Prantik; Satyamurty, C.; Raju, I. P.

    2009-12-01

    The deviatoric and double couple (DC) constrained moment tensor inversions of multiple point sources (10-20 s) for regional (or local) earthquakes, developed by Zahradnik et al. (2005), has been applied on the data of nine significant Bhuj aftershocks of Mw4.4- Mw5.6 recorded at three-component 5-15 accelerograph and 5-11 seismograph stations (epicentral distances < 130 km). The deviatoric moment tensor solutions of events on the north Wagad fault (NWF) in the 15-29 km depth range reveal a systematic depth-wise variation in the faulting patterns. At shallow depth (~ 15 km), they suggest a left lateral strike-slip movement with a minor reverse component along a south dipping plane (~ 61°), whereas, at 18-22 km depth range they change to pure reverse movement on a preferred south dipping plane (10-54°) and finally they change to the normal movement with minor strike-slip (S-S) component at deeper (25-29 km) depth range. The deviatoric MT solution of one event on the south Wagad fault (SWF) suggests a reverse movement with a minor S-S component on a 35° southeast dipping plane at 24 km depth. The deviatoric MT solutions for two events on the Gedi fault reveal a reverse movement with a minor left-lateral strike-slip component on an E-W trending and south dipping (40-61°) plane at 3-4 km depth. Whereas, one event on the Island belt fault (IBF) suggests a right lateral strike slip movement with a normal component on an almost vertical (~ 79°) plane at 29 km depth. The deviatoric moment tensor solutions of all the nine events show a larger (94-99%) double-couple (DC) component at shallow (3-15 km) depth range suggesting domination of brittle failure in the upper crust beneath the Kachchh region. However, the deeper events show larger non-DC (i.e. compensated linear vector dipole, CLVD) component suggesting increase in deviation from the double-couple (DC) solution in the lower crust (15-30 km depth range). This increase in non-DC component could be attributed to the

  6. An empirical approach for real-time earthquake damage assessement: an alternative of shake maps

    NASA Astrophysics Data System (ADS)

    Pirentis, A. P.; Halaris, Th.; Papadopoulos, G. A.

    2009-04-01

    The production of reliable shake maps in real time is not always possible, e.g. due to lack of adequate data or of trustable relations between ground acceleration and elements of the macroseismic field. Then, an alternative is proposed: the rapid production of the expected macroseismic field, within few minutes after focal parameters of an earthquake have been determined, on the basis of empirical relations between focal parameters and elements of the macroseismic field such as maximum seismic intensity, Im, and area, Si, defined by isoseismal of degree i. The purpose of this research initiative is the implementation of the results for early warning as regards the impact of strong earthquakes immediately after their occurrence. A data set of about 147 shallow, instrumental earthquakes that occurred in Greece from 1911 up to the end of 90's has been compiled and empirical relations were investigated between earthquake focal parameters on one hand and Im and Si on the other. The focal depth as well as the epicentral location are critical parameters in this procedure. However, reliable focal depth determinations are available only for the last 15 years or so. On the other hand, the geomorphological configuration of Greece makes the earthquake impact very sensitive to the epicentral distance. In fact, all the other parameters being equal the impact is quite different for inland, coastal and open-sea earthquake sources. For these reasons a simplified distance-from-the-coastline criterion is introduced and employed in order to classify the earthquakes in three distinct classes: inland, coastal and open sea, respectively. The data set compiled indicates that for strong earthquakes the meizoseismal extends at a radius of no more than 30 km from the epicentre. Therefore, the class of coastal earthquakes includes those having their epicentres at a distance of no more than 30 km from the closest coast. Then, for each one of the three classes of earthquake events simple linear

  7. The Neutral Atmosphere Parameters on Measurements Using the Artificial Periodic Irregularities. Techniques, processing, results.

    NASA Astrophysics Data System (ADS)

    Tolmacheva, Ariadna V.; Bakhmetieva, Nataliya V.; Grigoriev; Kalinina, Elena E.

    The measurements with the aid of the artificial periodic irregularities (APIs) were begun in 1990. The APIs are created in the ionosphere illuminated by a high power HF radio wave of a frequency below the critical one. The APIs diagnostics is based upon observation of the Bragg backscatter of the pulsed probe radio waves from the periodic structure. The amplitudes and phases of the probe signals back scattered by the APIs are measured. At the E-region heights the APIs relax in the ambipolar diffusion process. Based on this fact we could determine the neutral atmosphere parameters suggesting that the processes of isothermal on small scales (3-5 km) and the electron, ion and neutral temperatures are equal at the E-region heights. The atmospheric height scale H and the neutral atmospheric temperature T are determined on the height dependence of the relaxation times tau(z). The altitude step is about 3 km. Whole height interval of the measurements of τ is equal to about 20-30 km. Selecting small height intervals step by step we obtain altitude dependences T(z), nu(z) and rho(z). Such a way was employed because the steady state is achieved on the scales 20-30 km for a long time. We obtained a lot of information about dynamical phenomena in the lower thermosphere. These results are presented in the report. Firstly, there were temperature profiles with minimum about 100-140 K above 100 km in the equinoctial periods. But in summer of 1999 temperature maximum was observed on z = 100 km. Secondary, there were often profiles with the wave-like variations and with the vertical scale of about to 4-6 km. The temporal variations of the atmospheric parameters had periods from 15 minutes to some hours. These variations caused by the propagation of the internal gravity and tide waves. Planetary waves produce the longer temporal variations. Thirdly, we observed some cases of the instability growth. The dependencies of the atmospheric parameters on the solar and geomagnetic activity

  8. Retrieval of temperature profiles from CHAMP for climate monitoring: intercomparison with Envisat MIPAS and GOMOS and different atmospheric analyses

    NASA Astrophysics Data System (ADS)

    Gobiet, A.; Kirchengast, G.; Manney, G. L.; Borsche, M.; Retscher, C.; Stiller, G.

    2007-07-01

    This study describes and evaluates a Global Navigation Satellite System (GNSS) radio occultation (RO) retrieval scheme particularly aimed at delivering bias-free atmospheric parameters for climate monitoring and research. The focus of the retrieval is on the sensible use of a priori information for careful high-altitude initialisation in order to maximise the usable altitude range. The RO retrieval scheme has been meanwhile applied to more than five years of data (September 2001 to present) from the German CHAllenging Minisatellite Payload for geoscientific research (CHAMP) satellite. In this study it was validated against various correlative datasets including the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the Global Ozone Monitoring for Occultation of Stars (GOMOS) sensors on Envisat, five different atmospheric analyses, and the operational CHAMP retrieval product from GeoForschungsZentrum (GFZ) Potsdam. In the global mean within 10 to 30 km altitude we find that the present validation observationally constrains the potential RO temperature bias to be <0.2 K. Latitudinally resolved analyses show biases to be observationally constrained to <0.2-0.5 K up to 35 km in most cases, and up to 30 km in any case, even if severely biased (about 10 K or more) a priori information is used in the high altitude initialisation of the retrieval. No evidence is found for the 10-35 km altitude range of residual RO bias sources other than those potentially propagated downward from initialisation, indicating that the widely quoted RO promise of "unbiasedness and long-term stability due to intrinsic self-calibration" can indeed be realised given care in the data processing to strictly limit structural uncertainty. The results thus reinforce that adequate high-altitude initialisation is crucial for accurate stratospheric RO retrievals. The common method of initialising, at some altitude in the upper stratosphere, the hydrostatic integral with an upper

  9. Retrieval of temperature profiles from CHAMP for climate monitoring: intercomparison with Envisat MIPAS and GOMOS and different atmospheric analyses

    NASA Astrophysics Data System (ADS)

    Gobiet, A.; Kirchengast, G.; Manney, G. L.; Borsche, M.; Retscher, C.; Stiller, G.

    2007-02-01

    This study describes and evaluates a Global Navigation Satellite System (GNSS) radio occultation (RO) retrieval scheme particularly aimed at delivering bias-free atmospheric parameters for climate monitoring and research. The focus of the retrieval is on the sensible use of a priori information for careful high-altitude initialisation in order to maximise the usable altitude range. The RO retrieval scheme has been meanwhile applied to more than five years of data (September 2001 to November 2006) from the German CHAllenging Minisatellite Payload for geoscientific research (CHAMP) satellite. In this study it was validated against various correlative datasets including the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the Global Ozone Monitoring for Occultation of Stars (GOMOS) sensors on Envisat, five different atmospheric analyses, and the operational CHAMP retrieval product from GeoForschungsZentrum (GFZ) Potsdam. In the global mean within 10 to 30 km altitude we find that the present validation observationally constrains the potential RO temperature bias to be <0.2 K. Latitudinally resolved analyses show biases to be observationally constrained to <0.2-0.5 K up to 35 km in most cases, and up to 30 km in any case, even if severely biased (about 10 K or more) a priori information is used in the high altitude initialisation of the retrieval. No evidence is found for the 10-35 km altitude range of RO bias sources other than those potentially propagated downward from initialisation, indicating that the widely quoted RO promise of "unbiasedness and long-term stability due to intrinsic self-calibration" can indeed be realized given care in the data processing to strictly limit structural uncertainty. The results demonstrate that an adequate high-altitude initialisation technique is crucial for accurate stratospheric RO retrievals and that still common methods of initialising the involved hydrostatic integral with an upper boundary temperature or

  10. Deep Structures of The Angola Margin

    NASA Astrophysics Data System (ADS)

    Moulin, M.; Contrucci, I.; Olivet, J.-L.; Aslanian, D.; Géli, L.; Sibuet, J.-C.

    1 Ifremer Centre de Brest, DRO/Géosciences Marines, B.P. 70, 29280 Plouzané cedex (France) mmoulin@ifremer.fr/Fax : 33 2 98 22 45 49 2 Université de Bretagne Occidentale, Institut Universitaire Europeen de la Mer, Place Nicolas Copernic, 29280 Plouzane (France) 3 Total Fina Elf, DGEP/GSR/PN -GEOLOGIE, 2,place de la Coupole-La Defense 6, 92078 Paris la Defense Cedex Deep reflection and refraction seismic data were collected in April 2000 on the West African margin, offshore Angola, within the framework of the Zaiango Joint Project, conducted by Ifremer and Total Fina Elf Production. Vertical multichannel reflection seismic data generated by a « single-bubble » air gun array array (Avedik et al., 1993) were recorded on a 4.5 km long, digital streamer, while refraction and wide angle reflection seismic data were acquired on OBSs (Ocean Bottom Seismometers). Despite the complexity of the margin (5 s TWT of sediment, salt tectonics), the combination of seismic reflection and refraction methods results in an image and a velocity model of the ground structures below the Aptian salt layer. Three large seismic units appear in the reflection seismic section from the deep part on the margin under the base of salt. The upper seismic unit is layered with reflectors parallel to the base of the salt ; it represents unstructured sediments, filling a basin. The middle unit is seismically transparent. The lower unit is characterized by highly energetic reflectors. According to the OBS refraction data, these two units correspond to the continental crust and the base of the high energetic unit corresponds to the Moho. The margin appears to be divided in 3 domains, from east to west : i) a domain with an unthinned, 30 km thick, continental crust ; ii) a domain located between the hinge line and the foot of the continental slope, where the crust thins sharply, from 30 km to less than 7 km, this domain is underlain by an anormal layer with velocities comprising between 7,2 and 7

  11. Role Stratospheric Balloon Magnetic Surveys in Development of Analytical Global Models of the Geomagnetic Field

    NASA Astrophysics Data System (ADS)

    Brekhov, O. M.; Tsvetkov, Yu. P.; Ivanov, V. V.; Filippov, S. V.; Tsvetkova, N. M.

    2015-09-01

    The results of stratospheric balloon gradient geomagnetic surveys at an altitude of ‘-~3O km with the use of the long (6 km) measuring base oriented along the vertical line are considered. The purposes of these surveys are the study of the magnetic field formed by deep sources, and the estimation of errors in modern analytical models of the geomagnetic field. The independent method of determination of errors in global analytical models of the normal magnetic field of the Earth (MFE) is substantiated. The new technique of identification of magnetic anomalies from surveys on long routes is considered. The analysis of gradient magnetic surveys on board the balloon, revealed the previously unknown features of the geomagnetic field. Using the balloon data, the EMM/720 model of the geomagnetic field (http://www.ngdc.noaa.gov/geomag/EMM) is investigated, and it is shown that this model unsatisfactorily represents the anomalous MFE, at least, at an altitude of 30 km, in the area our surveys. The unsatisfactory quality of aeromagnetic (ground-based) data is also revealed by the method of wavelet analysis of the ground-based and balloon magnetic profiles. It is shown, that the ground-based profiles do not contain inhomogeneities more than 1 30 km in size, whereas the balloon profiles (1000 km in the strike extent) contain inhomogeneities up to 600 km in size an the location of the latte coincides with the location of the satellite magnetic anomaly. On the basis of balloon data is shown, it that low-altitude aeromagnetic surveys, due to fundamental reasons, incorrectly reproduce the magnetic field of deep sources. This prevents the reliable conversion of ground-based magnetic anomalies upward from the surface of the Earth. It is shown, that an adequate global model of magnetic anomalies in the circumterrestrial space, developed up to 720 spherical harmonics, must be constructed only in accordance with the data obtained at satellite and stratospheric altitudes. Such a model

  12. Seismological investigations of the subduction zone plate interface: New advances and challenges

    NASA Astrophysics Data System (ADS)

    Rietbrock, Andreas; Garth, Tom; Hicks, Stephen

    2015-04-01

    In the last decade, huge advances have been made in analysing the slip distribution of large megathrust earthquakes and how slip relates to geodetic locking, shedding light on the character of the seismic cycle in subduction zones. Recently, a number of studies have suggested that at convergent plate boundaries, geodetic locking may be closely related to slip distribution of subsequent large earthquakes, as found recently for the Maule 2010 and Tohoku 2011 earthquakes. However, the physical (e.g. seismic) properties along the subduction zone interface are still poorly constrained, posing a major limitation to our physical understanding of both geodetic locking and earthquake rupture process. Here, we present high-resolution seismic tomography results (P- and S-wave velocity), as well as earthquake locations to make a detailed investigation of seismic properties along the portion of the plate interface that ruptured during the 2010 Maule earthquake. Additionally, to test the robustness of our models, we performed numerous numerical tests including changes to the parameterization, synthetic recovery tests and bootstrap analysis. We find P-wave velocities of about 5.7 km/s at 10 km depth and linearly increasing to 7.5 km/s at a depth of 30 km. Between 30 km and 43 km, P-wave velocities are relatively constant at around 7.5 km/s before a subsequent increase to 8.3 km/s at larger depths (>60 km) is observed. The Poisson's ratio is significantly elevated, at values of up to 0.35 at shallow depths of 10km to 15km, before reaching less elevated values of 0.28-0.29 in the depth range between 20km and 43km. Comparison of these velocities to petrological models shows good agreement below 30 - 50 km depth. At shallower depths though P-wave velocities are significantly lower, which together with the elevated poisons ratio indicates that this portion of the mega thrust is highly hydrated, suggesting that material properties may in part control the seismogenic character of

  13. Implications of the Northridge earthquake for strong ground motions from thrust faults

    USGS Publications Warehouse

    Somerville, P.; Saikia, C.; Wald, D.; Graves, R.

    1996-01-01

    The peak accelerations recorded on alluvial sites during the Northridge earthquake were about 50% larger than the median value predicted by current empirical attenuation relations at distances less than about 30 km. This raises the question of whether the ground motions from the Northridge earthquake are anomalous for thrust events or are representative of ground motions expected in future thrust earthquakes. Since the empirical data base contains few strong-motion records close to large-thrust earthquakes, it is difficult to assess whether the Northridge ground motions are anomalous based on recorded data alone. For this reason, we have used a broadband strong-motion simulation procedure to help assess whether the ground motions were anomalous. The simulation procedure has been validated against a large body of strong-motion data from California earthquakes, and so we expect it to produce accurate estimates of ground motions for any given rupture scenario, including blind-thrust events for which no good precedent existed in the strong-motion data base until the occurrence of the Northridge earthquake. The ground motions from the Northridge earthquake and our simulations of these ground motions have a similar pattern of departure from empirical attenuation relations for thrust earthquakes: the peak accelerations are at about the 84th percentile level for distances within 20 to 30 km and follow the median level for larger distances. This same pattern of departure from empirical attenuation relations was obtained in our simulations of the peak accelerations of an Elysian Park blind-thrust event prior to the occurrence of the Northridge earthquake. Since we are able to model this pattern with broadband simulations, and had done so before the Northridge earthquake occurred, this suggests that the Northridge strong-motion records are not anomalous and are representative of ground motions close to thrust faults. Accordingly, it seems appropriate to include these

  14. Surface temperatures in the polar regions from Nimbus 7 temperature humidity infrared radiometer

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.

    1994-01-01

    Monthly surface temperatures in the Arctic and Antarctic regions have been derived from the 11.5 micrometer thermal infrared channel of the Nimbus 7 temperature humidity infrared radiometer (THIR) for a whole year in 1979 and for a winter and a summer month from 1980 through 1985. The data set shows interannual variability and provides spatial details that allow identification of temperature patterns over sea ice and ice sheet surfaces. For example, the coldest spot in the southern hemisphere is observed to be consistently in the Antarctic plateau in the southern hemisphere, while that in the northern hemisphere is usually located in Greenland, or one of three other general areas: Siberia, the central Arctic, or the Canadian Archipelago. Also, in the southern hemisphere, the amplitude of the seasonal fluctuation of ice sheet temperatures is about 3 times that of sea ice, while in the northern hemisphere, the corresponding fluctuations for the two surfaces are about the same. The main sources of error in the retrieval are cloud and other atmospheric effects. These were minimized by first choosing the highest radiance value from the set of measurements during the day taken within a 30 km by 30 km grid of each daily map. Then the difference of daily maps was taken and where the difference is greater than a certain threshold (which in this case is 12 C), the data element is deleted. Overall, the monthly maps derived from the resulting daily maps are spatially and temporally consistent, are coherent with the topograph y of the Antarctic continent and the location of the sea ice edge, and are in qualitative agreement with climatological data. Quantitatively, THIR data are in good agreement with Antarctic ice sheet surface air temperature station data with a correlation coefficient of 0.997 and a standard deviation of 2.0 C. The absolute values are not as good over the sea ice edges, but a comparison with Russian 2-m drift station temperatures shows very high correlation

  15. The 5- or 10-km Marikenloop Run: A Prospective Study of the Etiology of Running-Related Injuries in Women.

    PubMed

    van der Worp, Maarten P; de Wijer, Anton; van Cingel, Robert; Verbeek, André L M; Nijhuis-van der Sanden, Maria W G; Staal, J Bart

    2016-06-01

    Study Design Prospective cohort. Background The popularity of running events is still growing, particularly among women; however, little is known about the risk factors for running-related injuries in female runners. Objectives The aims of this study were to determine the incidence and characteristics (site and recurrence) of running-related injuries and to identify specific risk factors for running-related injuries among female runners training for a 5- or 10-km race. Methods Four hundred thirty-five women registered for the Marikenloop run of 5 or 10 km were recruited. Follow-up data were collected over 12 weeks using questionnaires, starting 8 weeks before the event and ending 4 weeks after the event. Two orthopaedic tests (navicular drop test and extension of the first metatarsophalangeal joint) were performed in the 8 weeks before the event. Running-related injuries, defined as running-related pain of the lower back and/or the lower extremity that restricted running for at least 1 day, were assessed at 1-, 2-, and 3-month follow-ups. Results Of 417 female runners with follow-up data (96%), 93 runners (22.3%) reported 109 running-related injuries, mainly of the hip/groin, knee, and lower leg. Multivariable Cox regression analysis showed that a weekly training distance of more than 30 km (hazard ratio = 3.28; 95% confidence interval [CI]: 1.23, 8.75) and a previous running injury longer than 12 months prior (hazard ratio = 1.88; 95% CI: 1.03, 3.45) were associated with the occurrence of running-related injuries. Conclusion Hip/groin, knee, and lower-leg injuries were common among female runners. Only weekly training distance (greater than 30 km) and previous running injury (greater than 12 months prior) were associated with running-related injuries in female runners training for a 5- or 10-km event. Level of Evidence Etiology, 2b. J Orthop Sports Phys Ther 2016;46(6):462-470. Epub 26 Apr 2016. doi:10.2519/jospt.2016.6402. PMID:27117730

  16. Effect of lateral stress on the consolidation state of sediment from the Nankai Trough

    NASA Astrophysics Data System (ADS)

    Valdez, R. D., II; Kitajima, H.; Saffer, D. M.

    2015-12-01

    In order to better understand the mechanics of seismogenesis and stress state along subduction plate boundaries, the Integrated Ocean Drilling Program (IODP) Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) program has focused on drilling a transect of boreholes across the subduction zone offshore SW Japan to collect core samples and geophysical logs. One primary target of the drilling effort is a major splay fault (the "megasplay") that branches from the décollement ~55 km landward of the trench and reaches the seafloor ~30 km from the trench. Three drillsites near the tip of the megasplay sampled the same 1.24-1.65 Ma slope apron sediment section at a reference location 0.75 km seaward of the megasplay fault tip (Site C0008), at the fault tip (Site C0022), and 0.30 km landward (Site C0004) where the section is overridden by accretionary prism sediment. We report on a suite of laboratory experiments conducted on coeval core samples from the three sites, to test the hypothesis that increasing horizontal stress with proximity to the megasplay fault leads to overconsolidation. We conducted uniaxial constant rate of strain (CRS) and triaxial consolidation experiments to define consolidation state and yield behavior of the sediment, and to estimate in situ effective stress magnitudes. The consolidation state is described in terms of the over-consolidation ratio (OCR), which is the ratio of stress at yield in the experiments to the in situ vertical stress expected for normal consolidation. Values of OCR increase with proximity to the fault, with values ranging from 0.5-1 at the reference Site C0008, to 1.4-1.5 at Site C0022 at the tip of the fault, to 1.7-2.1 in the footwall of the fault at Site C0004, defining a trend of progressively increasing overconsolidation. We attribute this pattern to increasing horizontal stress as the megasplay fault is approached. Assuming that the sediment is at a critical state (i.e. on the verge of shear failure) at the tip of the

  17. Two-Component Winds from Luminous Late-Type Stars

    NASA Astrophysics Data System (ADS)

    Airapetian, V. S.; Offman, L.; Robinson, R.; Carpenter, K.; Davila, J.

    1998-01-01

    We present the results of a magnetohydrodynamic (MHD) simulation of winds from luminous late-type stars using a 2.5D, non-linear MHD computer code. In this simulation we assume that the wind is generated within a hydrostatic atmosphere with an initial isothermal pressure scale height of 0.072 Rstar and a radial magnetic field. We also assume a transverse density gradient which we we refer to as a ``chromospheric hole''. Tortional Alfven waves are generated at the stellar surface by a forcing function having a single frequency, which is comparable to the turn-over frequency of convective cells in giant stars. To ensure that we are accurately assessing the terminal velocity of the wind, we carried out the calculations to a height of 20 stellar radii and a time period of more than 180 Alfven transit times, which ensures that a steady state has been reached. In the higher density (low Alfven velocity) regions outside of the ``chromospheric hole'' the Alfven waves are freely propagating. Ponderomotive forces associated with these waves drive radial, compressive motions and contribute to stellar wind acceleration. The compressive motions then excite slow magnetosonic waves which non-linearly steepen into solitary waves that propagate on top of a background flow similar to the case of solar coronal holes. This produces a fast (40-80 km/s) and relatively dense component of the wind. In the lower density ``chromospheric hole'' region the Alfven waves are strongly reflected and produce an outflow with both radial and azimuthal velocities which are ~ 10% of the local Alfven speed. This component of the wind is slow ( ~ 10-30 km/s) and less dense than the wind initiated outside of the hole. Depending on the magnetic topology in the atmosphere of a luminous late - type star, we may therefore expect either one (fast) or two components to the wind. Our results are consistent with recent observations of two discrete components to the wind in the K5 III hybrid star gamma Dra. These

  18. AirCore-HR: A high-resolution column measurement to enhance the knowledge on the vertical distribution of CO2 and CH4

    NASA Astrophysics Data System (ADS)

    Membrive, Olivier; Crevoisier, Cyril; Danis, François; Hertzog, Albert; Sweeney, Colm; Picon, Laurence; Durry, Georges; Amarouche, Nadir; Engel, Andreas; Boenisch, Harald

    2015-04-01

    The AirCore-HR (high-resolution) instrument is a simple and innovative atmospheric sampling system inspired from the NOAA AirCore (Karion et al. 2010). It consists of a 300m long coiled stainless steel tube (200m 1/8 in. and 100m 1/4 in. linked together as one). AirCore-HR allows balloon measurements of GHG vertical profiles (CO2 & CH4) from the surface up to approximately 30 km. It has been developed at LMD in partnership with NOAA and differs from other AirCores by its high vertical resolution: 100m at the surface up to 200m at 8km, then 100m at 8km up to 1 km at 30 km. AirCores rely on positive changes in ambient pressure for passive sampling of the atmosphere and are flown open at one end and closed at the other. The AirCore-HR closes at landing and the sample is measured with a continuous analyser for trace gas mole fraction. Our instrument was flown for the first time during the stratospheric balloon campaign operated by the French space agency CNES in Timmins (Ontario, Canada) in August 2014 on the "EdS-Stratéole" flight. The multi-instrument Gondola of this flight carried several instruments, including two others that measured CO2 & CH4 in situ: the Pico-SDLA (based on laser spectrometry) from GSMA, University of Reims & INSU Division Technique and two other AirCores with lower vertical resolution from Frankfurt University. The simultaneous flight of these instruments under the same balloon allows for direct comparison between the different measurements of mixing ratio profiles. We compare profiles from the AirCore-HR and in situ measurements. Moreover, AirCores provide extremely innovative means of observation that will provide a priori knowledge on the variations of methane and carbon dioxide for spaceborne total column measurements or model simulations. Here, we show the usefulness of the high vertical resolution in the upper troposphere and stratosphere for interpreting observations of total and partial column of methane and carbon dioxide from current

  19. Space–Time Covariation of Mortality with Temperature: A Systematic Study of Deaths in France, 1968–2009

    PubMed Central

    Todd, Nicolas

    2015-01-01

    Background The temperature–mortality relationship has repeatedly been found, mostly in large cities, to be U/J-shaped, with higher minimum mortality temperature (MMT) at low latitudes being interpreted as indicating human adaptation to climate. Objectives Our aim was to partition space with a high-resolution grid to assess the temperature–mortality relationship in a territory with wide climate diversity, over a period with notable climate warming. Methods The 16,487,668 death certificates of persons > 65 years of age who died of natural causes in continental France (1968–2009) were analyzed. A 30-km × 30-km grid was placed over the map of France. Generalized additive model regression was used to assess the temperature–mortality relationship for each grid square, and extract the MMT and the RM25 and RM25/18 (respectively, the ratios of mortality at 25°C/MMT and 25°C/18°C). Three periods were considered: 1968–1981 (P1), 1982–1995 (P2), and 1996–2009 (P3). Results All temperature–mortality curves computed over the 42-year period were U/J-shaped. MMT and mean summer temperature were strongly correlated. Mean MMT increased from 17.5°C for P1 to 17.8°C for P2 and to 18.2°C for P3 and paralleled the summer temperature increase observed between P1 and P3. The temporal MMT rise was below that expected from the geographic analysis. The RM25/18 ratio of mortality at 25°C versus that at 18°C declined significantly (p = 5 × 10–5) as warming increased: 18% for P1, 16% for P2, and 15% for P3. Conclusions Results of this spatiotemporal analysis indicated some human adaptation to climate change, even in rural areas. Citation: Todd N, Valleron AJ. 2015. Space–time covariation of mortality with temperature: a systematic study of deaths in France, 1968–2009. Environ Health Perspect 123:659–664; http://dx.doi.org/10.1289/ehp.1307771 PMID:25803836

  20. Broadband Marine Magnetotelluric Exploration of the East Pacific Rise at 9 N

    NASA Astrophysics Data System (ADS)

    Myer, D. G.; Key, K.; Constable, S.

    2005-12-01

    In February 2004, we conducted the world's largest academic broadband marine magnetotelluric (MT) experiment at the RIDGE2000 integrated study site (ISS) on the East Pacific Rise (EPR). Forty broadband EM receivers were deployed a total of 72 times to yield 69 sites of data. Twenty instruments were deployed in a small aperture (30 km) transect of densely spaced MT sites across the ridge at the ISS ``bull's eye'' focus area at 9°50' N. Further south, 40 sites were collected along a 200 km aperture transect at 9°30'} N. This larger aperture transect was positioned to avoid 3D structure associated with the Lamont seamounts and the Clipperton transform. The site density in the middle 30 km of the longer transect matches the density of the smaller transect, providing two separate data sets for shallow imaging. Twelve additional MT sites were collected in a grid along the ridge axis just north of the longer transect. Robust multi-station MT processing has provided good quality MT impedance responses for most of the data. Eigenvalue analysis of the robustly estimated spectral density matrix for arrays of 3 to 4 MT sites show high signal-to-noise ratios for periods between about 20 s to 5000 s. Based on our earlier pilot MT experiment of 4 sites (Key and Constable, 2000), this bandwidth of data is sensitive to structures from the near surface to about 300 km depth. We will present pseudo-sections of both MT transects as well as 2D conductivity models computed using a new adaptive finite-element modeling technique. Key issues of the ridge magmatic and hydrothemal systems to be addressed by this experiment are: 1. The distribution, vertical extent and volume fraction of melt present in the mid to lower crust. 2. The extent that hydrothermal circulation plays a role in heat removal from the crust as well as the linkages between hydrothermal activity and crustal magma. 3. The extent of melt accumulation at the base of the crust. Does a relatively thin layer of concentrated