Abstract Axial Seamount on the Juan de Fuca Ridge is a site of ongoing volcanic activity. The vertical component deformation can be observed with ambient seawater pressure gauges, which have excellent short‐term resolution. However, gauge drift adds additional and significant uncertainty in estimates long‐period deformation; rates equivalent to 20–30 cm/yr been observed. One way circumvent make differential measurements relative distant presumably stable seafloor reference site. Such require...

Abstract One commonly used method to measure and detect centimeter‐scale changes on land is structure‐from‐motion (SfM) photogrammetry, wherein sets of digital images are generate three‐dimensional spatial models. Subcentimeter accuracy useful for geodetic studies achievable when these surveys conducted or from the air. This has made its way into marine environments by scuba, remotely operated vehicle, autonomous underwater vehicle‐based largely in context mapping. Repeated SfM...

Seafloor pressure gauges are used in marine geodesy to detect vertical displacement of the seafloor. Instrumental gauge drift is often larger than sought after geophysical and oceanographic signals. We performed a 12 month laboratory test on two new methods that aim reduce Paroscientific Digiquartz other transducers. In one method, reference quartz oscillator (RQO) installed adjacent but isolated from Bourdon tube whose stress measured by vibrating force transducer. another periodically...

Abstract Axial Seamount is a seafloor volcano with frequent eruptions and periodic cycles of inflation deflation. Seafloor pressure gauges monitor vertical deformation time, but inherent instrumental drift complicates biases geodetic interpretation. A corrected recorder was deployed on 6 July 2018, at coordinates 45° 57.29′ North latitude, −130° 0.56′ East longitude, depth 1,535 m. This system includes two independent quartz‐resonant gauges, which nearly continuously observe the pressure. At...

Abstract The boundary between the overriding and subducting plates is locked along some portions of Cascadia subduction zone. extent location locking affects potential size frequency great earthquakes in region. Because much offshore, measurements on land are incapable completely defining a zone up‐dip Deformation models indicate that record seafloor height changes accretionary prism can reveal locking. To detect such changes, we have initiated series calibrated pressure using an absolute...

Get PDF Email Share with Facebook Tweet This Post on reddit LinkedIn Add to CiteULike Mendeley BibSonomy Citation Copy Text L. S. Kiani, J. W. Dawson, P. H. Pax, G. Allen, D. R. Drachenberg, V. Khitrov, N. Schenkel, M. Messerly, Cook, and Crist, "Tunable, All-Fiber, Continuous Wave Oscillator in the E-band Operating 4F3/2 4I13/2 transition Neodymium," Conference Lasers Electro-Optics, OSA Technical Digest (online) (Optica Publishing Group, 2017), paper SM1L.7. Export BibTex Endnote (RIS)...

Important seafloor applications, including mine countermeasures, unexploded ordnance (UXO) surveys, salvage, and underwater pipeline cable tracking, require the detection, geo-registration, characterization of man-made targets on, or below, seafloor. Investigations in littoral environments can be time-consuming expensive due to challenges accurately tracking assets, difficulty quick effective site reconnaissance activities, high levels clutter nearshore areas, lack situational awareness...

To help facilitate the modeling of new fiber laser systems, such as those with complex functional microstructures, we report on a simplified methodology that can accommodate parasitic kinetic effects often present in systems. The essence our approach is to integrate kinetics over length gain medium at outset, thereby forfeiting longitudinally resolved information about system but simplifying its energetics analysis. illustrate benefits more conventional coupled-rate-equation analyses, apply...

This paper presents "ROVBus," a communications framework tailored to custom ROV development, that enables plug-and-play interconnection of various component tools via unified bus. The flexibility provided by this approach easy tooling for frameworks and allows them be range applications. will describe the ROVBus system architecture at block diagram level explore how can used quickly adapt common backbone on project basis. Successes challenges in achieving desired rapid development discussed.

Contaminants can severely limit the efficiency, laser damage threshold, and strength of photonic crystal fiber-based lasers. Such contamination occur due to environmental exposure during pulling or stacking rods tubes improper handling storage these glass components. A preform made by "stack draw" process is susceptible incorporating surface contaminants into bulk glass. We have adapted cleaning protocols originally developed for processing large fused silica optics National Ignition...

A hand-held laser-induced breakdown spectroscopy device was used to acquire spectral emission data from plasmas created on the surface of cerium-gallium alloy samples with Ga concentrations ranging 0 3 weight percent. Ionic and neutral lines two constituent elements were then extracted generate calibration curves relating line intensity ratios gallium concentration alloy. The I 287.4 nm determined be superior for purposes detection determination.A limit below 0.25% achieved using a...

The boundary between the overriding and subducting plates is locked along some portions of Cascadia subduction zone. extent location locking affects potential size frequency great earthquakes in region. Because much offshore, measurements on land are incapable completely defining a zone up-dip Deformation models indicate that record seafloor height changes accretionary prism can reveal locking. To detect such changes, we have initiated series calibrated pressure using an absolute...

This collection contains data from a Self-Calibrating Pressure Recorder (SCPR) deployed at Axial Seamount 2013 September to 2015 August. The include seafloor height change (cm) that have been converted pressure (kPa). Corrections of ocean tides and gauge drift applied the data.

A large mode area fiber coupler based on multi-core spectrally and modally filtered transfer is presented. Relative coupling to the cross-port above 80% was measured. Only fundamental observed given a multimode launch.