ALGORITHMIC AUDITING: CHASING AI ACCOUNTABILITY

Calls for audits to expose and mitigate harms related to algorithmic decision systems are proliferating,3 and audit provisions are coming into force—notably in the E.U. Digital Services Act.4 In response to these growing concerns, research organizations working on technology accountability have called for ethics and/or human rights auditing of algorithms and an Artificial Intelligence (AI) audit industry is rapidly developing, signified by the consulting giants KPMG and Deloitte marketing their services.5 Algorithmic audits are a way to increase accountability for social media companies and to improve the governance of AI systems more generally. They can be elements of industry codes, prerequisites for liability immunity, or new regulatory requirements.6 Even when not expressly prescribed, audits may be predicates for enforcing data-related consumer protection law, or what U.S. Federal Trade Commissioner Rebecca Slaughter calls “algorithmic justice.” 7 The desire for audits reflect a growing sense that algorithms play an important, yet opaque, role in the decisions that shape people’s life chances—as well as a recognition that audits have been uniquely helpful in advancing our understanding of the concrete consequences of algorithms in the wild and in assessing their likely impacts.

Basement and Regional Structure Along Strike of the Queen Charlotte Fault in the Context of Modern and Historical Earthquake Ruptures

The Queen Charlotte fault (QCF) is a dextral transform system located offshore of southeastern Alaska and western Canada, accommodating similar to 4.4 cm/yr of relative motion between the Pacific and North American plates. Oblique convergence along the fault increases southward, and how this convergence is accommodated is still debated. Using seismic reflection data, we interpret offshore basement structure, faulting, and stratigraphy to provide a geological context for two recent earthquakes, an M-w 7.5 strike-slip event near Craig, Alaska, and an M-w 7.8 thrust event near Haida Gwaii, Canada. We map downwarped Pacific oceanic crust near 54 degrees N, between the two rupture zones. Observed downwarping decreases north and south of 54 degrees N, parallel to the strike of the QCF. Bending of the Pacific plate here may have initiated with increased convergence rates due to a plate motion change at similar to 6 Ma. Tectonic reconstruction implies convergence-driven Pacific plate flexure, beginning at 6 Ma south of a 10 degrees bend the QCF (which is currently at 53.2 degrees N) and lasting until the plate translated past the bend by similar to 2 Ma. Normal-faulted approximately late Miocene sediment above the deep flexural depression at 54 degrees N, topped by relatively undeformed Pleistocene and younger sediment, supports this model. Aftershocks of the Haida Gwaii event indicate a normal-faulting stress regime, suggesting present-day plate flexure and underthrusting, which is also consistent with reconstruction of past conditions. We thus favor a Pacific plate underthrusting model to initiate flexure and accommodation space for sediment loading. In addition, mapped structures indicate two possible fault segment boundaries along the QCF at 53.2 degrees N and at 56 degrees N.USGS Earthquake Hazards External Grants ProgramNational Earthquake Hazards Reduction ProgramUTIG Ewing/Worzel FellowshipInstitute for Geophysic

Seismicity and structure of the Orozco transform fault from ocean bottom seismic observations

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy and the Woods Hole Oceanographic Institution February 1982In this thesis, seismic waves generated by sources ranging from 2.7 kg shots of TNT to magnitude 5 earthquakes are studied in order to determine the seismic activity and crustal structure of the Orozco transform fault. Most of the data were collected by a network of 29 ocean bottom seismometers (OBS) and hydrophones (OBH) which were deployed as part of project ROSE (Rivera Ocean Seismic Experiment). Additional information is provided by magnetic anomaly and bathymetric data collected during and prior to ROSE and by teleseismic earthquakes recorded by the WWSSN (Worldwide Seismic Station Network). In Chapter II, the tectonic setting, bathymetry and teleseismic history of the Orozco Fracture Zone are summarized. Covering an area of 90 x 90 km which includes ridges and troughs trending both parallel and perpendicular to the present spreading direction (approximately east-west), the bathymetry of the transform portion of the fracture zone does not resemble that of other transform faults which have been studied in detail. A detailed study of one of the largest teleseismic earthquakes (mb=5.1) indicates right lateral strike-slip faulting with a strike parallel to the present spreading direction and a focal depth of less than 5 km. The moment sum from teleseismic earthquakes suggests an average fault width of at most a few kilometers. Because the teleseismic earthquake locations are too imprecise to define the present plate boundary and the magnetic anomaly data are too sparse to resolve the recent tectonic history, more questions are raised than are answered by the results in this chapter. These questions provide the focus for the study of the ROSE data. Chapter III contains an examination of the transfer function between seafloor motion and data recorded by the MIT OBS. The response of the recording system is determined and the coupling of the OBS to the seafloor during tests at two nearshore sites is analysed. Applying these results to the ROSE data, we conclude that the ground motion in the absence of the instrument can be adequately determined for at least one of the MIT OBS deployed during ROSE. Hypocentral parameters for 70 earthquakes, calculated for an assumed laterally homogeneous velocity structure which was adapted from the results of several refraction surveys in the area, are presented in Chapter IV. Because of the large number of stations in the ROSE network, the epicentral locations, focal depths and source mechanisms are determined with a precision unprecedented in marine microseismic work. Relative to the assumed model, most horizontal errors are less than ±1 km; vertical errors are somewhat larger. All epicenters are within the transform region of the Orozco Fracture Zone. About half of the epicenters define a narrow line of activity parallel to the spreading direction and situated along a deep topographic trough which forms the northern boundary of the transform zone (region 1). Most well determined depths are very shallow (<4km) and no shallowing of activity is observed as the rise-transform intersection is approached. In fact, the deepest depths (4-10km) are for earthquakes within 10 km of the intersection; these apparent depth differences are supported by the waveforms recorded a t the MIT OBS. First motion polarities for all but two of the earthquakes in region 1 are compatible with right lateral strike-slip faulting along a nearly vertical plane striking parallel to the spreading direct ion. Another zone of activity is observed in the central part of the transform (region 2). The apparent horizontal and vertical distribution of activity is more scattered than for the first group and the first motion radiation patterns of these events do not appear to be compatible with any known fault mechanism. No difference can be resolved between the stress drops or b values in the two regions. In Chapter V, lateral variations in the crustal structure within the transform region are determined and the effect of these structures on the results of the previous chapter is evaluated. Several data sources provide information on different aspects of the crustal structure. Incident angles and azimuths of body waves from shots and earthquakes measured at one of the MIT OSS show systematic deflections from the angles expected for a laterally homogeneous structure. The effect of various factors on the observed angles and azimuths is discussed and it is concluded that at least some of the deflection reflects regional lateral velocity heterogeneity. Structures which can explain the observations are found by tracing rays through three dimensional velocity grids. High velocities are inferred at upper mantle depths beneath a shallow, north-south trending ridge to the west of the OBS, suggesting that the crust under the ridge is no thicker, and perhaps thinner, than the surrounding crust. Observations from sources in region 2 suggest the presence of a low velocity zone in the central transform between the sources and the receiver. That the presence of such a body provides answers to several of the questions raised in Chapter IV about the hypocenters and mechanisms of earthquakes in region 2 is circumstantial evidence supporting this model. These proposed structures do not significantly affect the hypocenters and fault plane solutions for sources in region 1. The crustal velocity structure beneath the north-south trending ridges in the central transform and outside of the transform zone is determined by travel time and amplitude modeling of the data from several lines of small shots recorded at WHOI OBH. Outside of the transform zone, a velocity-depth structure typical of oceanic crust throughout the world oceans is found from three unreversed profiles: a 1 to 2 km thick layer in which the velocity increases from about 3 to 6.7 km/sec overlies a 4 to 4.5 km thick layer with a nearly constant velocity of 6.8 km/sec. A reversed profile over one of the north-south trending ridges, on the other hand, indicates an anomalous velocity structure with a gradient of 0.5 sec-1 throughout most of the crust ( from 5.25 km/sec to 7.15 km/sec over 3.5 km). A decrease in the gradient at the base of the crust to about 0.1 sec-1 and a thin, higher gradient layer in the upper few hundred meters are also required to fit the travel time and amplitude data. A total crustal thickness of about 5.4 km is obtained. An upper mantle velocity of 8.0 to 8.13 km/sec throughout much of the transform zone is determined from travel times of large shots of TNT recorded at MIT and WHOI instruments. "Relocations" of the large shots relative to the velocity model assumed in Chapter IV support the conclusion from the ray tracing that results from region 2 may be systematically biased because of lateral velocity heterogeneity whereas results from region 1 are not affected. In the last chapter, the results on crustal structure and seismicity are combined in order to define the present plate boundary and to speculate on the history of the present configuration.This research was supported by the Office of Naval Research, under contracts N00014-75-C-0291 and N00014-80-C-027

Forming a Mogi Doughnut in the Years Prior to and Immediately Before the 2014 M8.1 Iquique, Northern Chile, Earthquake

Asperities are patches where the fault surfaces stick until they break in earthquakes. Locating asperities and understanding their causes in subduction zones is challenging because they are generally located offshore. We use seismicity, interseismic and coseismic slip, and the residual gravity field to map the asperity responsible for the 2014M8.1 Iquique, Chile, earthquake. For several years prior to the mainshock, seismicity occurred exclusively downdip of the asperity. Two weeks before the mainshock, a series of foreshocks first broke the upper plate then the updip rim of the asperity. This seismicity formed a ring around the slip patch (asperity) that later ruptured in the mainshock. The asperity correlated both with high interseismic locking and a circular gravity low, suggesting that it is controlled by geologic structure. Most features of the spatiotemporal seismicity pattern can be explained by a mechanical model in which a single asperity is stressed by relative plate motion

Cascadia Fore Arc Seismic Survey: Open-Access Data Available

The Cascadia subduction zone (CSZ), where the Juan de Fuca and Gorda plates subduct obliquely beneath North America at a rate of about 35 millimeters per year, poses major geological hazards to population centers of the northwestern United States. Despite the importance of the subducting slab in these hazards, the plate boundary is poorly mapped and understood, especially offshore

Synchronous oceanic spreading and continental rifting in West Antarctica

Magnetic anomalies associated with new ocean crust formation in the Adare Basin off north-western Ross Sea (43 – 26 Ma) can be traced directly into the Northern Basin that underlies the adjacent morphological continental shelf, implying a continuity in the emplacement of oceanic crust. Steep gravity gradients along the margins of the Northern Basin, particularly in the east, suggest that little extension and thinning of continental crust occurred before it ruptured and the new oceanic crust formed, unlike most other continental rifts and the Victoria Land Basin further south. A pre-existing weak crust and localisation of strain by strike slip faulting are proposed as the factors allowing the rapid rupture of continental crust

Integrating Science Needs with Advanced Seafloor Sensor Engineering to Provide Early Warning of Geohazards: Visioning Workshop and Roadmap for the Future

The workshop was funded by the National Science Foundation (NSF), OCE Division of Ocean Sciences (Award # 1817257). This report summarizes the key findings, outcomes, and recommendations of the workshop and serves as a draft of the comprehensive roadmap

Managing toxicities associated with immune checkpoint inhibitors: consensus recommendations from the Society for Immunotherapy of Cancer (SITC) Toxicity Management Working Group.

Cancer immunotherapy has transformed the treatment of cancer. However, increasing use of immune-based therapies, including the widely used class of agents known as immune checkpoint inhibitors, has exposed a discrete group of immune-related adverse events (irAEs). Many of these are driven by the same immunologic mechanisms responsible for the drugs\u27 therapeutic effects, namely blockade of inhibitory mechanisms that suppress the immune system and protect body tissues from an unconstrained acute or chronic immune response. Skin, gut, endocrine, lung and musculoskeletal irAEs are relatively common, whereas cardiovascular, hematologic, renal, neurologic and ophthalmologic irAEs occur much less frequently. The majority of irAEs are mild to moderate in severity; however, serious and occasionally life-threatening irAEs are reported in the literature, and treatment-related deaths occur in up to 2% of patients, varying by ICI. Immunotherapy-related irAEs typically have a delayed onset and prolonged duration compared to adverse events from chemotherapy, and effective management depends on early recognition and prompt intervention with immune suppression and/or immunomodulatory strategies. There is an urgent need for multidisciplinary guidance reflecting broad-based perspectives on how to recognize, report and manage organ-specific toxicities until evidence-based data are available to inform clinical decision-making. The Society for Immunotherapy of Cancer (SITC) established a multidisciplinary Toxicity Management Working Group, which met for a full-day workshop to develop recommendations to standardize management of irAEs. Here we present their consensus recommendations on managing toxicities associated with immune checkpoint inhibitor therapy

Geochemical observations on Hydrate Ridge, Cascadia Margin during R/V BROWN-ROPOS cruise : August 1998

A massive release of methane on the Cascadia Hydrate Ridge was documented during a ROPOS program in August 1998, consistent with previously reported observations in 1996. An extensive survey of the seafloor revealed that the seeps lie within a narrow band trending 109 degrees. This feature parallels larger mounds imaged by Seabeam as well as larger structures of the accretionary prism such as the Daisy bank. The area of intense bubbling is characterized by extensive bacterial mats. Large clam fields were observed ten's of meters away from the gas seeps. A third province with carbonate blocks but no clams or bacterial mats was mapped approximately 200 meters away from the seeps. To constrain fluid flow through the sediments, we deployed 8 osomotic flow meters. The areas of gas discharge are discrete and highly focussed within conduits with an approximate cross-sectional area of 5 cm2. We estimate the gas flow rate to be on the order of 5 liters/minute. While the subsurface plumbing is unknown, the high flow rate of the sampled gas seep suggests a very short transit time from the gas source (presumably the base of the BSR at 70 mbsf) to the sea floor. The Rn/CH4 ratio in gas samples collected from the gas vents is very high, approximately 50 dpm/liter (stp) CH4. Using these values, we estimate that the time required for the fluids to transit 70 m is approximately 1 hour. To further constrain the nature of the discharging fluids, we will analyze samples for their elemental and isotopic composition. Methane hydrate should be stable at the temperature and pressure conditions at the seafloor on Hydrate Ridge. Indeed, solid hydrate was observed to form within the gas samplers as well as on the camera itself, supporting the conclusion that methane is rapidly transported to the seafloor from beneath the BSR within discrete conduits, most likely separated from significant amounts of pore water. When discharged at the seafloor, some of the methane precipitate as hydrate and some continues to rise within the water column. Bubbles were observed with the ROV up to 50 meters above the seafloor. This methane generates a plume in the water column, which was first documented during the 1996 GEOMAR survey. The most pronounced methane plumes observed during 1998 occur nearest to the active discharge sites, where methane concentrations up to 800 nmol/l were recorded

Geochemical observations on Hydrate Ridge, Cascadia Margin : July 1999

Geophysical and biogeochemical processes associated with fluid venting from active and passive continental margins will receive significant scientific and economic attention into the next century and are of major societal relevance. An important unknown among these interrelated processes is the role played by methane gas hydrates, at and below the seafloor, and their impact on the oceans and atmosphere. Research scientists from institutions in the USA, Germany and Canada have developed a research project dedicated to a long-term study of continental margin gas hydrates on the Cascadia Accretionary Prism, under the acronym "TECFLUX". It is conceived as multi-stage research effort with the eventual goal of measuring the energy and chemical fluxes associated with this system, determining its temporal variability in response to tectonic and oceanographic forcing, and evaluating its impact on marine biogeochemical cycles