<p>Institution: Halmstad University/School of Teacher Education (LUT)</p><p>Course: C-level paper, 15 credits</p><p>Term: Spring 2010</p><p>Title: Two Sides of the Same Coin - A study of EFL-teachers knowledge regarding the divergences between British and American English; and the challenges which arise from having more than one accepted variety of English in EFL teaching.</p><p>Pages: 41</p><p>Writer: Linda Jensen</p><p>Purpose: The purpose of this essay is to ascertain if Swedish EFL teachers have sufficient knowledge regarding the differences between BrE and AmE, the two major varieties of English. Furthermore, I aim to examine what challenges are created when two models of English, BrE and AmE, are accepted in upper secondary schools in Sweden.</p><p>Method: A quantitative web-based survey.Material: Questionnaire filled in by 59 EFL teachers in upper secondary schools in Halland, Sweden.</p><p>Main results: Upper secondary EFL teachers in Halland, Sweden do appear to have a basic knowledge of the differences between BrE and AmE and as such a majority placed themselves in the correct category. However, there is a lack of consistency and all the teachers mixed the two varieties to some extent. The challenges that arise from having two accepted varieties in Swedish schools are amongst other things the question of the consistency rule, dealing with the value system associated with British and American English and the question of whether Mid-Atlantic English should be accepted as a third educational standard.</p><p>Keywords: British English, American English, Mid-Atlantic English, divergence, EFL, consistency, challenges, value system.</p>

<p><strong>Abstract</strong></p><p>Many would agree that English has become a global language that has spread all over the world. English has been the primary foreign language in the Swedish school curriculum since the Second World War and most Swedes have some English language proficiency. Today, Swedes are not only subjected to English in school, but also come across English every day in media, in the streets or at work.</p><p>A number of studies have been done on how Swedish students use English and of their attitudes towards it, but not much on how Swedes that are no longer under school influence view the matter. This study has examined the attitudes and preferences towards English among 60 adults. Most of them have a positive attitude towards English and believe that the use of English in Sweden will increase in the future. Even so, they show little concern that English might be a future threat towards Swedish.</p><p>Both men and women find media as their primary source of English influence and there was only one minor difference to be noted when comparing attitudes between different age groups. The older female informants reported to use less English and have lower skills than the rest. No such trend was seen among the men belonging to the same age group. Besides this, some interesting gender differences were seen. The female informants reported to have a stronger preference for British English and the male informants showed preference for American English. These gender differences would be interesting to study further.</p>

Institution: Halmstad University/School of Teacher Education (LUT) Course: C-level paper, 15 credits Term: Spring 2010 Title: Two Sides of the Same Coin - A study of EFL-teachers knowledge regarding the divergences between British and American English; and the challenges which arise from having more than one accepted variety of English in EFL teaching. Pages: 41 Writer: Linda Jensen Purpose: The purpose of this essay is to ascertain if Swedish EFL teachers have sufficient knowledge regarding the differences between BrE and AmE, the two major varieties of English. Furthermore, I aim to examine what challenges are created when two models of English, BrE and AmE, are accepted in upper secondary schools in Sweden. Method: A quantitative web-based survey.Material: Questionnaire filled in by 59 EFL teachers in upper secondary schools in Halland, Sweden. Main results: Upper secondary EFL teachers in Halland, Sweden do appear to have a basic knowledge of the differences between BrE and AmE and as such a majority placed themselves in the correct category. However, there is a lack of consistency and all the teachers mixed the two varieties to some extent. The challenges that arise from having two accepted varieties in Swedish schools are amongst other things the question of the consistency rule, dealing with the value system associated with British and American English and the question of whether Mid-Atlantic English should be accepted as a third educational standard. Keywords: British English, American English, Mid-Atlantic English, divergence, EFL, consistency, challenges, value system.

On May 29th 2008 two earthquakes with moment magnitude of Mw ~6 occurred in the southwestern part of Iceland. The second earthquake struck within only seconds after the first, on a fault ~5 km west from the first fault. The aftershock sequence was recorded by 14 seismic stations during the subsequent 34 days. The recorded earthquakes were detected and located with a Coalesence Microseismic Mapping (CMM) technique. The output data from this program has been used as basis for the tomography algorithm PStomo_eq, which simultaneously inverts for both P- and S-wave velocities and relocates the events. Within the study area of 46×36 km the three-dimensional velocity structure has, successfully but not conclusively, been modeled to depths of ~10 km. The Vp/Vs ratio varies from 1.74 to 1.82 within the study area. The velocity increases with depth starting from 2 km where the P-wave velocity is 4.6 km/s and the S-wave velocity is 2.7 km/s, at a depth of 10 km the P-wave velocity is 6.9 km/s and S-wave velocity is 4.0 km/s. In the horizontal slices a high velocity area is seen in the northwestern part of model. This is interpreted to be caused by a magma body rising up from below and lithifying at high pressure. From cross-sections a large low velocity zone is seen in the western part of model area concentrated above the seismicity. The low velocity anomaly is found between depths of 2 km to 4 km, stretching from 21.5° to 21.2° W. It is interpreted to be caused by high porosity within the area. The depth to the brittle crust is increasing from the western part of the model towards the eastern part, right in the middle of the model it abruptly decreases again. The depth to the base of the brittle crust is increasing from 7 km in west to 9 km in the middle of model. / Den 29:e maj 2008 inträffade två jordbävningar med magnitud Mw ~6 på sydvästra Island. Den första jordbävningen följdes tätt av en andra jordbävning på en förkastning ~5 km väster om den första. Påföljande efterskalvssekvens registrerades av 14 seismiska stationer under 34 dagar efter huvudskalven. De registrerade skalven har detekterats och lokaliserats med en Coalesence Microseismic Mapping (CMM) teknik. Utdata från detta program har använts som grund för tomografin som genomförts med PStomo_eq, en algoritm som inverterar oberoende för både P- och S-vågs hastigheter och samtidigt omlokaliserar eventen. Inom det undersökta området på 46×36 km har en tredimensionell hastighetsmodell, om än inte slutgiltigt, modellerats för djup ned till 10 km. Vp/Vs kvoten varierar mellan 1.74 och 1.82 inom studieområdet. Hastigheterna ökar med ökande djup, på ett djup av 2 km är P-vågs hastigheten 4.6 km/s och S-vågs hastigheten 2.7 km/s och vid 10 km är P-vågs hastigheten 6.9 km/s och S-vågs hastigheten 4.0 km/s. I den nordvästra delen av modellen återfinns en höghastighetszon. Denna tolkas vara orsakad av en magma kropp som stigit och kristalliserat under högt tryck. De vertikala tvärsnitten visar en låghastighetsanomali i västra delen av modellen, koncentrerat ovan seismiciteten. Denna anomali sträcker sig från ett djup på 2 km ned till 4 km, från 21.5° till 21.2° V. Den tolkas vara orsakad av en hög grad av porositet. Djupet för den bräckliga jordskorpan ökar från väster till öster i modellen, för att i mitten abrupt minska igen. Basen av den bräckliga skorpan ökar från 7 km i väst till 9 km i mitten av modellen.

Abstract Many would agree that English has become a global language that has spread all over the world. English has been the primary foreign language in the Swedish school curriculum since the Second World War and most Swedes have some English language proficiency. Today, Swedes are not only subjected to English in school, but also come across English every day in media, in the streets or at work. A number of studies have been done on how Swedish students use English and of their attitudes towards it, but not much on how Swedes that are no longer under school influence view the matter. This study has examined the attitudes and preferences towards English among 60 adults. Most of them have a positive attitude towards English and believe that the use of English in Sweden will increase in the future. Even so, they show little concern that English might be a future threat towards Swedish. Both men and women find media as their primary source of English influence and there was only one minor difference to be noted when comparing attitudes between different age groups. The older female informants reported to use less English and have lower skills than the rest. No such trend was seen among the men belonging to the same age group. Besides this, some interesting gender differences were seen. The female informants reported to have a stronger preference for British English and the male informants showed preference for American English. These gender differences would be interesting to study further.

Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Mar. 4, 2009). Includes bibliographical references (p. 50-59).

The importance of the site discovery process in archaeological research should not be underestimated. The primary function of an archaeological site discovery survey is to locate, identify and to some degree evaluate the horizontal extent of buried cultural resources (King 1998; Neuman and Sanford 2001, 2010). This thesis examines the effectiveness of archaeological surface and subsurface survey techniques commonly used in the Mid-Atlantic Region of eastern North America. The present work uses a cultural resource management archaeological site discovery survey conducted in 2004 on a 549-acre property located in Loudoun County, Virginia as a case study. The variety of environments, resources and methods employed during this site discovery survey present a unique opportunity to analyze a variety of survey techniques. Specifically, point provenience surface collection, gridded surface collection, shovel testing and close-interval shovel testing are examined. This thesis reveals several key findings. First, all forms of survey technique have benefits and limitations, based on levels of intensity and survey environment. Second, survey objectives, survey environment and logistics all play a part in the decision process for choosing an appropriate survey technique. Third, state guidelines, while an influencing stricture born out of a rich intellectual tradition, should not solely dictate the survey process. Fourth, the use of a variety of complementary techniques is vital to thoroughness in the archaeological process, and, finally, it is necessary to repeatedly investigate and monitor a landscape whenever possible. / Anthropology

Understanding factors that influence a species' distribution and abundance across their annual cycle is needed for range-wide conservation planning. Every year during spring migration, thousands of federally threatened (U.S.A.) and endangered (Canada) migratory Western Atlantic red knots (Calidris canutus rufa, 'red knot') use Virginia's barrier islands as stopover habitat to regain the fat required to continue flights to breeding grounds. Because the red knot completes one of the longest avian migrations in the world and relies on variable prey resources at its stopover grounds, the red knot exemplifies the challenges faced by long-distance migrant shorebirds. These challenges may be exacerbated by climate change, as long-distance migrants may be unable to adapt quickly to changing prey ranges and abundances, resulting in spatial and temporal mismatches between predators and prey. More specifically, as climate change causes ocean temperatures near Virginia's barrier islands to rise, organisms that live within the intertidal zone, like blue mussels (Mytilus edulis), are experiencing range shifts. Here, we 1) confirmed what prey red knots select in Virginia, 2) addressed the factors that affect red knot site selection, red knot flock size, and prey abundances across Virginia's barrier island intertidal shoreline during 2007 – 2018, and 3) predicted the origin of juvenile blue mussels, a key prey resource for red knots in Virginia. To determine which prey are most available to red knots in Virginia, we collected sand and peat substrate core samples from Virginia's ocean intertidal zone and counted the number of prey in each sample. We compared these prey availability data to prey DNA data obtained from fecal DNA metabarcoding analyses on red knot feces (n = 100) collected on peat and sand substrates between 2017 – 2019. Red knots consumed prey from Orders Veneroida (clams), Mytiloida (mussels), Diptera (flies), and Amphipoda/Calanoida (crustaceans). While crustaceans were the most abundant prey on both sand (70.80% of total prey counted) and peat (74.88%) substrates, red knots selected crustaceans less than expected given their availability. Red knots selected clams and mussels, supporting their status as bivalve specialists in Virginia. After determining which prey red knots consumed and selected in Virginia, we predicted the number of red knots using Virginia's barrier island stopover during their migratory stopover (May 14 – 27, 2007 – 2018) annually. We used confirmed prey, tide, distance to known roosts, and red knot winter counts from Tierra del Fuego to inform zero-inflated negative binomial mixed-effects regression models of red knot site selection and flock size in Virginia. We also used generalized linear mixed-effects regression models to determine how climatic and geomorphological factors affected prey abundances. Modeled red knot peak counts were highest in 2012 (11,644) and lowest in 2014 (2,792; x̄ = 7,055, SD = 2,841); the trend over time was variable but there was no evidence of a linear increase or decrease. Red knots selected foraging locations with more prey, though red knot flock size did not consistently relate to prey abundance. Tide, substrate, and water temperature affected prey availability. While different prey responded to these covariates in variable ways, prey generally were most abundant on peat banks at low tide. Given the importance of blue mussels in the red knot's diet and distribution in Virginia, if the blue mussel's range continues to contract northward, red knots could be faced with additional fat replenishment challenges. We analyzed the variation in blue mussels from 2010 – 2018 by collecting core samples on peat banks in Virginia and counting the number of blue mussels in the cores. To approximate the origin of Virginia's juvenile blue mussels and determine how continued ocean temperature warming may further affect the blue mussel's range contraction, we conducted oxygen stable isotope (δ¹⁸O_c) analyses on 74 blue mussel shell umbos (the first portion of the shell precipitated) and shell edges (the most recently precipitated shell) to compare and predict where different portions of the shell were formed. We compared blue mussel shell compositions to δ¹⁸O_c calculated in equilibrium with regional ocean water using recorded δ¹⁸O_w data and sea surface temperature data from ocean buoys between New Hampshire and Virginia. Blue mussel abundance/core sample declined over the duration of our study (Spearman's rank correlation coefficient: ρ(rho) = -0.31, p < 0.001), with the highest abundance in 2010 (x̄ blue mussels/core sample = 537.88, SE = 85.85) and lowest in 2016 (x̄ = 34.08 blue mussels/core sample, SE = 6.96). Blue mussel umbos (x̄ δ¹⁸O_c = -0.23‰, SE = 0.12) contained more positive δ18Oc than shell edges (x̄ δ¹⁸O_c = -0.53‰, SE = 0.20), suggesting that Virginia's blue mussels originated from ocean populations in more saline and/or colder water than that within Virginia's intertidal zone. Blue mussel umbo δ¹⁸O_c were not different than δ¹⁸O_c calculated in equilibrium with regional ocean water off the Virginia and Delaware coasts, suggesting that Virginia's blue mussels originated in ocean waters between Delaware and Virginia; however, they may have originated in waters as far north as New York in some years, potentially decreasing the risk of blue mussels being completely extirpated from Virginia in the near future. While red knots currently use spring migratory stopovers across the United States' Atlantic Coast, from Florida to New Jersey, the largest spring concentrations of knots are confined to the Delaware Bay and Virginia's barrier islands. Because these stopover grounds support large proportions of the red knot's migratory population, any changes in the factors that affect red knots at these stopover sites could have lasting implications for red knots. The blue mussel's range contraction and decline over time in Virginia, for example, is concerning from a conservation perspective. Red knots require easily accessible and abundant prey resources to efficiently replenish fat-stores needed for continued migration and breeding. Additionally, because red knots breed within a narrow period, any delays on stopover grounds could prevent red knots from breeding, even if they survive migration. Our research demonstrates that red knots use prey abundance as a determinant when selecting foraging locations, and that peat banks, while only sporadically available across the barrier islands at mid- to low-tides, contain higher prey abundances than sand. Thus, to continue maximizing the availability of prey in Virginia, measures should continue to be taken to allow natural island migration processes that encourage the presence of both sand and peat substrates. Beach nourishment and stabilization projects are often used on coastal beaches to prevent shoreline erosion; however, such actions prevent the formation of peat banks by blocking island migration processes. A reduction in peat banks could decrease the abundance of prey available to red knots, making weight gain during the critical stopover period more challenging for red knots. Additionally, beach nourishment through sand replenishment buries invertebrate prey, potentially causing mass prey mortality and reducing shorebirds' ability to access deeply buried prey. To prevent the loss of important peat banks on these islands, and to prevent disrupting predator-prey interactions, managers should continue their ongoing focus on allowing natural processes to occur on Virginia's barrier islands. / Doctor of Philosophy / Red knots (Calidris canutus rufa) are imperiled shorebirds that migrate thousands of kilometers each year from wintering grounds as far south as Argentina to breeding grounds in the Canadian Arctic. To migrate such long distances, red knots use stopover habitat, like Virginia's barrier islands, to regain the fat required to continue flights to breeding grounds. Climate change is causing the ranges of important red knot prey, such as blue mussels (Mytilus edulis), to shift. Red knots may be unable to quickly adapt to changes in prey abundances on stopover grounds, making it more challenging for them to gain the weight required for successful migration and breeding. Thus, understanding the factors that may affect red knots in Virginia are important for successful management of this shorebird. Here, we determined what prey red knots consume in Virginia, addressed the factors that affect red knots in Virginia, and predicted the origin of blue mussels, an important prey resource for red knots in Virginia. We collected sand and peat substrate samples from Virginia's ocean intertidal zone to determine what prey were available to red knots and collected red knot feces to determine what prey red knots consume. Red knots consumed clams, mussels, fly larvae, and crustaceans in Virginia and showed preference for clams and mussels over the more abundant crustaceans. Red knots selected foraging locations that had higher prey abundances than unused sites. The relationship between red knots and prey was affected by the tidal cycle, with the highest abundance of prey available and most birds foraging at low tide when peat banks were exposed. After confirming that red knots preferentially consume blue mussels, which is experiencing a northward range contraction due to increasing ocean temperatures, we analyzed how blue mussel numbers have changed over time in Virginia. Blue mussel numbers declined over the duration of our study. We also analyzed blue mussel shells to help determine where the blue mussels were spawned, as shells contain environmental clues that relate to the conditions within which the shell forms. The juvenile blue mussels red knots consumed on Virginia's peat banks likely originated in ocean waters between Delaware and Virginia, but potentially in waters as far north as New York, possibly using ocean currents to travel to Virginia's intertidal zone. Because migratory stopovers, like Virginia's barrier islands, support a large percentage of the total red knot migratory population, any changes in factors that affect red knots during their spring stopover, like prey availability, may negatively affect red knots. Because red knots need to quickly consume large quantities of prey to gain the weight needed for continued migration and breeding, managers should continue to prevent factors that negatively affect prey in Virginia. For example, we found that peat banks support high quantities of red knot prey; thus, continuing to ensure that peat banks are able to form on the islands is paramount. However, peat banks form through shoreline erosion and overwash, two natural processes which are often portrayed negatively. Beach nourishment and stabilization projects are commonly used in other coastal areas to prevent shoreline erosion and overwash along coastal beaches. If Virginia's barrier island beaches are nourished, natural processes like shoreline erosion may be less likely to occur. The absence of shoreline erosion on Virginia's barrier islands would preclude the formation of peat banks, likely decreasing prey availability for red knots. Beach nourishment also buries invertebrate prey, as sand is deposited along the beaches' intertidal zone. The disturbance caused by nourishment combined with the reduction in prey caused by it could negatively affect red knots in Virginia. Managers should continue to protect both peat and sand substrates by further allowing natural processes, like shoreline erosion, to occur on Virginia's barrier islands.

White-nose syndrome (WNS) has reduced the abundance of many bat species within the United States' mid-Atlantic region, including the endangered Indiana (Myotis sodalis), threatened Myotis septentrionalis (northern long-eared bat) and other bats of conservation concern, such as Perimyotis subflavus (tri-colored bat), Myotis leibii (eastern small-footed bat) and Myotis lucifugus (little brown bat). Impacts to Eptesicus fuscus (big brown bat) populations have been negative, positive or neutral. Migratory bat species such as Lasiurus borealis (eastern red bat) are not impacted by WNS. To determine changes within the National Park Service National Capital Region bat communities, I surveyed the area with mist netting and active acoustic sampling (2016–2018) and compared findings to pre-WNS (2003–2004) data. I documented a significant reduction in the numbers and distributions of M. lucifugus and P. subflavus, a decrease in the distribution of M. septentrionalis, and an increase in Eptesicus fuscus. Documented M. septentrionalis reproduction suggests that portions of the National Capital Region may be important bat conservation areas. To explore the relationship between bat life history and passive acoustic sampling echolocation call data, as well as to review the sampling effort required to detect the presence of extant species, I used mist-netting captures and acoustic call data collected 2015 – 2018 within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. Based on locally estimated scatterplot smoothing line calculations, I determined that the highest levels of maternity season acoustic activity for Eptesicus fuscus and Lasiurus borealis corresponded primarily to lactation periods. To determine sampling effort, I developed simulations based on species accumulation curves for individual species within different physiographic regions and land-cover types. I determined that the smallest sampling efforts typically corresponded to sampling additional sites versus sampling the same sites with more nights. Detection effort varied greatly by species, physiographic region and land-cover type. Eptesicus fuscus diet has been well-studied throughout North America with visual identification methods from fecal and stomach content samples. Next-generation sequencing provides large genetic data sets analyses in a cost-effective manner and has been used to identify bat prey items. I collected Eptesicus fuscus fecal samples from mid-Atlantic regions and used next-generation sequencing to identify their prey. I documented high variation between survey areas, but did not note a clear pattern of urbanization or fragmentation impacts upon Insecta diversity. All order-level taxa that I documented had been previously documented in morphological studies; however, I did document new families, genera and species. However, I would suggest caution in using next-generation sequencing technologies as authoritative sources for documenting new diet taxa, as I noted frequent occurrences of confounding environmental DNA within the samples. / Doctor of Philosophy / White-nose syndrome (WNS) has reduced the abundance of many bat species within the United States' mid-Atlantic region, including the endangered Indiana (Myotis sodalis), threatened Myotis septentrionalis (northern long-eared bat) and other bats of conservation concern, such as the Perimyotis subflavus (tri-colored bat), Myotis leibii (eastern small-footed bat) and Myotis lucifugus (little brown bat). WNS-impacts to Eptesicus fuscus (big brown bat) populations have been negative, positive or neutral. Migratory bat species such as Lasiurus borealis (eastern red bat) are not impacted by WNS. To determine changes within the National Park Service National Capital Region bat communities, I captured bats with mist-netting techniques and recorded bat echolocation calls with active acoustics (20-minute periods; 2016–2018) and compared findings to pre-WNS (2003–2004) data. I documented a significant reduction in the numbers and distributions of M. lucifugus and P. subflavus, a decrease in the distribution of M. septentrionalis, and an increase in Eptesicus fuscus. Documented M. septentrionalis reproduction suggests that portions of the National Capital Region may be important bat conservation areas. To explore the relationship between bat echolocation calls recorded with passive (over-night) acoustic data and bat reproduction trends, as well as the amount of effort required to document bat species, I sampled 849 sites with passive acoustics and 482 sites with mist-netting during 2016 – 2018 within the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. I determined that the highest levels of acoustic activity for Eptesicus fuscus and Lasiurus borealis (eastern red bat) within the maternity season are associated with the period of highest levels of lactation. To determine sampling effort, I used simulations to detect species in different landscape conditions. I determined that sampling additional sites requires less sampling effort than sampling more nights. The amount of effort required to detect each bat species varied, as did the impact of different landscape conditions. Eptesicus fuscus diet has been well-studied throughout North America by identifying insect parts in feces and stomach contents. Next-generation sequencing is a process which produced large amounts of genetic data sets in a cost-effective manner, and it can be used to identify prey within bat feces. I collected Eptesicus fuscus fecal samples from mid-Atlantic regions and used next-generation sequencing to identify potential prey. I determined that bat diet varied greatly based on survey area and number of feces analyzed. At the order-level, I did not document new taxa: however, I did document new families, genera and species. However, I would suggest caution in using next-generation sequencing technologies as authoritative sources for documenting new diet taxa, as many taxa apparent within my samples were subsequently excluded, as the bats may have been incidentally ingested them.

Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, and the Woods Hole Oceanographic Institution), 2001. / Page 250 blank. / Includes bibliographical references. / Half of the ocean crust is formed at spreading centers with total opening rates less than 40 km/Myr. The objective of this Thesis is to investigate temporal variations in active ridge processes and crustal aging at slow-spreading centers by comparing axial crustal structure with that on conjugate flanks of the slow-spreading Mid-Atlantic Ridge (MAR) (full rate, 20 km/Myr) and the ultra-slow spreading Southwest Indian Ridge (SWIR) (full rate, 14 km/Myr). Seismic refraction data collected along the rift valley and flanking rift mountains of the OH-1 segment (35ʻN) at the MAR show that the entire crustal section is constructed within a zone that is less than 5 km wide. Shallow-level hydrothermal circulation within the axial valley is suggested by the rift mountain seismic profiles, which show that the upper crust is 20% thinner and 16% faster along strike than zero-age crust. These effects probably result from fissure sealing within the extrusive crust. Deeper crustal velocities remain relatively constant at the segment midpoint within the first 2 Myr, but are reduced near the segment offsets presumably by faulting and fracturing associated with uplift out of the rift valley. / (cont.) A temporal variation in axial melt supply is suggested by a 15% difference in along-strike crustal thickness between the rift valley and rift mountains, with relatively less melt supplied today than 2 Ma. Crustal accretion at the SWIR appears to occur in a similar manner as at the MAR, although gravity and seismic data indicate that the average crustal thickness is 2-4 km less at theultra-slow spreading SWIR. A 25 Myr record on both flanks of the ridge shows that seafloor spreading has been highly asymmetric through time, with 35% faster crustal accretion on the Antarctic (south) plate. A small-offset non-transform discontinuity between two ridge segments is just as stable as two neighboring transform discontinuities, although a single mantle Bouguer gravity anomaly centered over the non-transform offset indicates that this boundary does not significantly perturb underlying mantle flow. Off-axis magnetic anomalies are recorded with high fidelity despite the very low spreading rates and the absence of a basaltic upper crust in one area. The lower crust may be the dominant off-axis carrier of the magnetic signal, contrary to traditionalmodels of crustal magnetic structure. Morphological and gravity data show evidence of asymmetric crustal accretion across the SWIR ridge axis, with slightly warmer mantletemperatures beneath the slower-spreading African (north) plate. / by Allegra Hosford. / Ph.D.