COSEISMIQ: First results of high resolution imaging of the shallow crust and relocation of induced seismicity in the Hengill area, Iceland

2020 ◽  
Author(s):  
Anne Obermann ◽  
Pilar Sánchez-Pastor ◽  
Alejandro Duran ◽  
Tobias Diehl ◽  
Vala Hjörleifsdóttir ◽  
...  
Keyword(s):  
High Resolution ◽  
Induced Seismicity ◽  
Seismic Velocity ◽  
Active Faults ◽  
Seismic Events ◽  
Volcanic Complex ◽  
High Resolution Imaging ◽  
First Results ◽  
Resolution Imaging ◽  
Shallow Crust

<p>For the future development of deep geothermal energy exploitation in Europe, large magnitude induced seismic events are an obstacle. On the other hand, the analysis of induced microseismicity allows to obtain the spatial distribution of fractures within the reservoir, which can help, not only to identify active faults that may trigger large induced seismic events, but also to optimize hydraulic stimulation operations and to locate the regions with higher permeability, enhancing energy production. The project COSEISMIQ (COntrol SEISmicity and Manage Induced) integrates seismic monitoring and imaging techniques, geomechanical models and risk analysis methods with the ultimate goal of implementing innovative tools for the management of the risks posed by induced seismicity and demonstrate their usefulness in a commercial scale application in Iceland.</p><p>Our demonstration site is the Hengill region in Iceland. The Hengill volcanic complex is located in SW Iceland on the plate boundary between the North American and Eurasian plates. In this region, the two largest geothermal power plants of Iceland are currently in operation, the Nesjavellir (120MW electricity) and the Hellisheidi (300MW electricity) power stations. In October 2018, we densified the permanent seismic network run by ISOR and IMO in this area (14 stations) with 23 broadband seismic stations.</p><p>We present the project and show first results from high resolution imaging of the shallow crust with ambient seismic noise, as well as first results from the relocated seismic events. The ambient noise imaging highlights an area of low seismic velocity close to the Þingvallavatn Lake, characteristic for the presence of supercritical fluids. The main geothermal production area is located as well in a low velocity zone that reaches 200 meters depth below Hellisheidi and around 700 meters below Nesjavellir.</p><p> </p>

First results from the faint object camera - High-resolution imaging of the Pluto-Charon system

1991 ◽  
Vol 374 ◽  
pp. L65 ◽  
Author(s):  
R. Albrecht ◽  
C. Barbieri ◽  
J. C. Blades ◽  
A. Boksenberg ◽  
P. Crane ◽  
...  
Keyword(s):  
High Resolution ◽  
High Resolution Imaging ◽  
Faint Object ◽  
First Results ◽  
Resolution Imaging

scholarly journals High-resolution imaging of Virgo cluster galaxies – I. Observational techniques and first results

1991 ◽  
Vol 253 (1) ◽  
pp. 21P-24P ◽  
Author(s):  
N. R. Tanvir ◽  
T. Shanks ◽  
J. V. Major ◽  
A. P. Doel ◽  
C. N. Dunlop ◽  
...  
Keyword(s):  
High Resolution ◽  
Virgo Cluster ◽  
High Resolution Imaging ◽  
Cluster Galaxies ◽  
First Results ◽  
Resolution Imaging ◽  
Observational Techniques

Grooved Terrain on Ganymede: First Results from Galileo High-Resolution Imaging

Icarus ◽  
1998 ◽  
Vol 135 (1) ◽  
pp. 276-302 ◽  
Author(s):  
Robert T. Pappalardo ◽  
James W. Head ◽  
Geoffrey C. Collins ◽  
Randolph L. Kirk ◽  
Gerhard Neukum ◽  
...  
Keyword(s):  
High Resolution ◽  
High Resolution Imaging ◽  
First Results ◽  
Resolution Imaging

High-resolution Imaging by Optical Aperture Synthesis: First Results from the MAPPIT Project

1991 ◽  
Vol 9 (1) ◽  
pp. 162-163 ◽  
Author(s):  
J. G. Robertson ◽  
T. R. Bedding ◽  
R. G. Marson ◽  
P. R. Gillingham ◽  
R. H. Frater ◽  
...  
Keyword(s):  
High Resolution ◽  
Double Star ◽  
Aperture Synthesis ◽  
High Time Resolution ◽  
High Resolution Imaging ◽  
Primary Mirror ◽  
Optical Aperture ◽  
First Results ◽  
Resolution Imaging ◽  
Fringe Patterns

AbstractWe have successfully demonstrated optical aperture synthesis at the 4-m Anglo-Australian Telescope. By using a multi-hole mask over the (re-imaged) primary mirror and recording the resulting fringe patterns with high time resolution, diffraction-limited images of sufficiently bright objects can be reconstructed. The data processing uses closure phases to overcome the effects of atmospheric turbulence. We show an image of the double star η Oph, with component separation 0″.45.

First results from IRENI—Rapid diffraction-limited high resolution imaging across the mid-infrared bandwidth

2010 ◽  
Author(s):  
Michael J. Nasse ◽  
Eric Mattson ◽  
Carol Hirschmugl ◽  
Adriana Predoi-Cross ◽  
Brant E. Billinghurst
Keyword(s):  
High Resolution ◽  
High Resolution Imaging ◽  
Mid Infrared ◽  
First Results ◽  
Resolution Imaging

Alternative approaches to ultra-high resolution imaging

1991 ◽  
Vol 49 ◽  
pp. 650-651
Author(s):  
J.M. Cowley
Keyword(s):  
High Resolution ◽  
High Voltage ◽  
High Resolution Electron Microscopy ◽  
Crystal Defects ◽  
High Resolution Imaging ◽  
General Applicability ◽  
Resolution Electron ◽  
Radiation Resistant ◽  
Resolution Imaging ◽  
Alternative Approaches

By extrapolation of past experience, it would seem that the future of ultra-high resolution electron microscopy rests with the advances of electron optical engineering that are improving the instrumental stability of high voltage microscopes to achieve the theoretical resolutions of 1Å or better at 1MeV or higher energies. While these high voltage instruments will undoubtedly produce valuable results on chosen specimens, their general applicability has been questioned on the basis of the excessive radiation damage effects which may significantly modify the detailed structures of crystal defects within even the most radiation resistant materials in a period of a few seconds. Other considerations such as those of cost and convenience of use add to the inducement to consider seriously the possibilities for alternative approaches to the achievement of comparable resolutions.

Principle and practice of high-resolution imaging with a field-emission TEM

1992 ◽  
Vol 50 (1) ◽  
pp. 138-139
Author(s):  
Max T. Otten ◽  
Wim M.J. Coene
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Incidence Angle ◽  
Temporal Coherence ◽  
Energy Spread ◽  
High Resolution Imaging ◽  
Major Improvement ◽  
High Resolution Images ◽  
Resolution Imaging

High-resolution imaging with a LaB6 instrument is limited by the spatial and temporal coherence, with little contrast remaining beyond the point resolution. A Field Emission Gun (FEG) reduces the incidence angle by a factor 5 to 10 and the energy spread by 2 to 3. Since the incidence angle is the dominant limitation for LaB6 the FEG provides a major improvement in contrast transfer, reducing the information limit to roughly one half of the point resolution. The strong improvement, predicted from high-resolution theory, can be seen readily in diffractograms (Fig. 1) and high-resolution images (Fig. 2). Even if the information in the image is limited deliberately to the point resolution by using an objective aperture, the improved contrast transfer close to the point resolution (Fig. 1) is already worthwhile.

Imaging of ferroelectric domain walls by electron holography

1992 ◽  
Vol 50 (1) ◽  
pp. 246-247
Author(s):  
Xiao Zhang
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Domain Walls ◽  
Ferroelectric Domain ◽  
Object Wave ◽  
Electron Holography ◽  
High Resolution Imaging ◽  
Quantitative Measurements ◽  
Resolution Imaging ◽  
Electron Microscopes

Electron holography has recently been available to modern electron microscopy labs with the development of field emission electron microscopes. The unique advantage of recording both amplitude and phase of the object wave makes electron holography a effective tool to study electron optical phase objects. The visibility of the phase shifts of the object wave makes it possible to directly image the distributions of an electric or a magnetic field at high resolution. This work presents preliminary results of first high resolution imaging of ferroelectric domain walls by electron holography in BaTiO3 and quantitative measurements of electrostatic field distribution across domain walls.

The method of replication affects metal film granularity and resolution

1989 ◽  
Vol 47 ◽  
pp. 708-709
Author(s):  
George C. Ruben
Keyword(s):  
Electron Beam ◽  
High Resolution ◽  
Film Thickness ◽  
Single Molecule ◽  
Metal Film ◽  
Vertical Surface ◽  
High Resolution Imaging ◽  
Controllable Factors ◽  
Resolution Imaging

Single molecule resolution in electron beam sensitive, uncoated, noncrystalline materials has been impossible except in thin Pt-C replicas ≤ 150Å) which are resistant to the electron beam destruction. Previously the granularity of metal film replicas limited their resolution to ≥ 20Å. This paper demonstrates that Pt-C film granularity and resolution are a function of the method of replication and other controllable factors. Low angle 20° rotary , 45° unidirectional and vertical 9.7±1 Å Pt-C films deposited on mica under the same conditions were compared in Fig. 1. Vertical replication had a 5A granularity (Fig. 1c), the highest resolution (table), and coated the whole surface. 45° replication had a 9Å granulartiy (Fig. 1b), a slightly poorer resolution (table) and did not coat the whole surface. 20° rotary replication was unsuitable for high resolution imaging with 20-25Å granularity (Fig. 1a) and resolution 2-3 times poorer (table). Resolution is defined here as the greatest distance for which the metal coat on two opposing faces just grow together, that is, two times the apparent film thickness on a single vertical surface.

Performance Evaluation of a Novel Type of Low-Energy Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 354-355
Author(s):  
Bertholdand Senftinger ◽  
Helmut Liebl
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Field Strength ◽  
Numerical Aperture ◽  
Low Energy ◽  
Energy Electron ◽  
High Resolution Imaging ◽  
Lens System ◽  
Resolution Imaging ◽  
Low Energy Electron

During the last few years the investigation of clean and adsorbate-covered solid surfaces as well as thin-film growth and molecular dynamics have given rise to a constant demand for high-resolution imaging microscopy with reflected and diffracted low energy electrons as well as photo-electrons. A recent successful implementation of a UHV low-energy electron microscope by Bauer and Telieps encouraged us to construct such a low energy electron microscope (LEEM) for high-resolution imaging incorporating several novel design features, which is described more detailed elsewhere.The constraint of high field strength at the surface required to keep the aberrations caused by the accelerating field small and high UV photon intensity to get an improved signal-to-noise ratio for photoemission led to the design of a tetrode emission lens system capable of also focusing the UV light at the surface through an integrated Schwarzschild-type objective. Fig. 1 shows an axial section of the emission lens in the LEEM with sample (28) and part of the sample holder (29). The integrated mirror objective (50a, 50b) is used for visual in situ microscopic observation of the sample as well as for UV illumination. The electron optical components and the sample with accelerating field followed by an einzel lens form a tetrode system. In order to keep the field strength high, the sample is separated from the first element of the einzel lens by only 1.6 mm. With a numerical aperture of 0.5 for the Schwarzschild objective the orifice in the first element of the einzel lens has to be about 3.0 mm in diameter. Considering the much smaller distance to the sample one can expect intense distortions of the accelerating field in front of the sample. Because the achievable lateral resolution depends mainly on the quality of the first imaging step, careful investigation of the aberrations caused by the emission lens system had to be done in order to avoid sacrificing high lateral resolution for larger numerical aperture.

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