Flat Ridges Research Articles

Landforms and landscape evolution in the Mylliem Granite Area, Meghalaya Plateau, Northeast India

The Mylliem granite is one of many igneous bodies within the basement complex of the Meghalaya Plateau, northeast India. Although relatively small in size at c. 90 km2, it is very diverse geomorphologically and shows a range of distinctive landscapes within its limits. Relict flat watershed ridges and topographic basins characterize the northern and eastern part of the pluton, whereas to the southwest the relief becomes higher, with steeper hillslopes and deeply incised valleys. Deep weathering and thick saprolites are abundant, as are residual landforms resulting from stripping of the saprolite: domes, tors and boulders. The major reason behind the diversity of granite landscape of the Mylliem pluton is the progress of headward erosion, initiated at the Dauki fault in the south of the Meghalaya. Headward erosion enhances local relief and hence, weathering systems. Multi‐concave morphology is gradually transformed into multi‐convex one, which is hypothesized to be the specific mode of plateau evolution and scarp retreat in granite bedrock.

A Clinical Study to assess the Efficacy of Commonly Available Denture Adhesive Materials in Mandibular Dentures

ABSTRACT Retention in mandibular dentures has always been a challenge for the treating dentist. Denture adhesives are known to improve the adhesive bond between the denture and the underlying tissues. However, denture adhesives still remain unexplored and not much is known about the efficacy of these materials in mandibular dentures especially in patients with poor foundations. The present study was carried out to compare the efficacy of different commercially available denture adhesives in relation to their retentive ability in patients with good well formed mandibular ridges and in patients with resorbed and flat mandibular ridges. Seventy edentulous patients, age range between 50 to 70 years, were selected. The patients were divided into 2 groups; group 1 comprised of 35 patients with good well formed mandibular ridges and group 2 consisted of 35 patients having low well rounded mandibular ridges. The adhesion and cohesion that developed between the dentures and the underlying tissues when the various materials were interposed between them was evaluated with the help of a test apparatus in newtons. Mean value of retention in denture without adhesive was 9.93 N and 24.53 N in resorbed and well formed ridges respectively. Use of denture adhesive materials led to a higher value of retention as opposed to when the dentures were used without adhesives. This was true for patients with good well formed mandibular ridges as well as for patients with poor foundations. Among the various denture adhesive powders tested, Fittydent showed better results, i.e. 29.56 and 33.05 in resorbed and well-formed ridges respectively as opposed to fixon which showed values of 16.47 and 27.70 respectively. How to cite this article Malhotra P, Yadav B, Yadav H, Phukela SS. A Clinical Study to assess the Efficacy of Commonly Available Denture Adhesive Materials in Mandibular Dentures. Int J Prosthodont Restor Dent 2013;3(4):125-130.

Lava accretion system around mid‐ocean ridges: Volcanic stratigraphy in the Wadi Fizh area, northern Oman ophiolite

Detailed lithological study combined with geochemical variations of lavas reveals the across‐axis accretionary process at Wadi Fizh in the northern Oman ophiolite. The >900 m thick V1 sequence is divided into the lower V1 (LV1), middle V1 (MV1) and upper V1 (UV1) sequence by 0.4 m and 0.8 m thick umbers at 410 mab (meters above the base of the extrusive rocks) and 670 mab, respectively. The lowest part of the LV1 (LV1a) consists of lobate sheet and pillow lava flows extruded on the relatively flat ridge crest. Elongate pillows at 230 mab are flows draping downslope from the ridge crest and characterize the lithofacies on the ridge flank. Just above a jasper layer at 270 mab, 130 m thick evolved lavas were transported from the crest and emplaced on the ridge flank (LV1b). Off‐axial accretionary processes recorded in the MV1 resulted in alternating flows of less evolved, depleted lava and evolved lava, suggesting that the MV1 off‐axial lava sequence comprises flows emanated from both on‐ and off‐axis source vents. The less evolved and depleted UV1 flows suggest independent sources distinct from the axial lavas. The Lasail Unit is regarded as a subunit of the V1 because it is comparable to the UV1 in the geological, petrological, and geochemical characteristics. The broad compositional range of the V1 sequence endorses a view that the Wadi Fizh area corresponds to a segment end of the Oman paleospreading system accompanied by off‐axis volcanism as in segment boundaries of the present East Pacific Rise.

Flapless Implant Surgery Using a Mini‐Incision

Traditional flapless implant surgery using a soft tissue punch device requires a circumferential excision of keratinized tissue at the implant site. A new flapless implant technique that can submerge implant fixtures is needed. This article describes a flapless implant surgery method using a mini-incision and compares the effects of soft tissue punch and mini-incision surgery on both the amount of osseointegration and the bone height around the implants using a canine mandible model. Bilateral, edentulated, flat alveolar ridges were created in the mandibles of six mongrel dogs. After a 3-month healing period, two implants were placed on each side of the mandible using either soft tissue punch or mini-incision procedures. After an additional 3-month healing period, a second stage surgery and transmucosal abutment attachment was performed for mini-incision implant cases. Following a 2-month healing period, the dogs were sacrificed to evaluate the osseointegration and bone height around the implants. Average bone height was 9.6 ± 0.4 mm in the soft tissue punch group and 9.8 ± 0.3 mm in the mini-incision group (p > .05). Average osseointegration was 70.4 ± 6.3% in the soft tissue punch group and 71.2 ± 7.1% in the mini-incision group (p > .05). No significant differences were noted between the two groups in vertical alveolar ridge height or bone/implant contact. Our findings support the clinical use of mini-incision implant surgery at sites where implants need to be protected below the soft tissue during the early phase of healing, particularly for patients with poor bone quality and/or low primary implant stability.

Influence of ridge cultivation and phacelia intercrop on weed infestation of root vegetables of the Asteraceae family

Abstract The field experiment focused on three high-inulin vegetable crops: chicory (Cichorium intybus L. var. sativum Bisch), black salsify (Scorzonera hispanica L.) and common salsify (Tragopogon porrifolius L.), and took into account two cultivation methods (flat soil and ridges) and a phacelia (Phacelia tanacetifolia L.) intercrop, the biomass of which was mixed with the soil during pre-winter ploughing. Cultivation without an intercrop served as the control. The studies aimed at evaluating the influence of ridge cultivation using a phacelia intercrop on the species composition and population of vegetable weeds as compared to traditional flat-soil cultivation with no intercrop. In total, 24 taxa in the primary and 31 taxa in the secondary weed populations (mostly characteristic for vegetable crops) were recorded in high-inulin species plantations. Monocarpic species such as Senecio vulgaris, Chenopodium album and Lamium amplexicaule dominated in the spring, while Stellaria media, Capsella bursa-pastoris and Urtica urens were most numerous at the end of the vegetation period. Applying phacelia as the intercrop and ploughing its biomass before winter significantly reduced the primary weed population for all of the cultivated crop species as compared to the no-intercrop cultivations. Phacelia grown as the intercrop reduced the occurrence of Senecio vulgaris, while favouring the development of Lamium amplexicaule. The cultivation system affected the primary weed infestation of vegetables, whereas it had no impact on the level of secondary weed infestation. At the beginning of the vegetation periods, fewer weeds grew in ridges than in the flat soil system. The crop species had no effect on the primary weed infestation, while it influenced weed numbers in the secondary. The lowest number of weeds was recorded in the secondary weed infestation of chicory, the well-developed leaf rosettes of which efficiently eliminated most of the weeds.

Stimulation of osteoblast activity by induction of Aloe vera and xenograft combination

Background Tooth extraction is generally followed by alveolar ridge resorption that later can cause flat ridge. Aloe vera have biogenic stimulator and hormone activities for wound healing. Purpose This study was aimed to know osteoblast activities in alvaeolar bone after induction of Aloe vera and XCB application. Methods Fifty four of Cavia cabaya were divided into three main groups. Group I was control group. Group II was filled with XCB and group III was filled with the combination of Aloe vera gel and XCB. Then, each group was divided into three sub groups according to timing, they are 14, 30, and 60 days after tooth extraction and application. Histology and morphology examination were performed on the harvested specimens. Results There were significant differences between the control group and the other groups filled with the combination of Aloe vera and xenograft concelous bovine (XCB). Conclusion The application of Aloe vera gel and xenograft decrease the number of osteoclast and increase the number of osteoblast in post tooth extraction alveolar bone structure indicating the new growth of alveolar bone.

Comparison of flap and flapless procedures for the stability of chemically modified SLA titanium implants: an experimental study in a canine model

Flapless implant surgery has been shown to accelerate recovery and increase the vascularity of the peri-implant mucosa after implant placement. The aim of this study was to compare dental implant stabilization patterns between flap and flapless implant surgeries over the first 8 weeks after implant placement. In 6 mongrel dogs, bilateral, edentulated, and flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants (Straumann SLA-active) were placed in each side of the mandible using either a flap or flapless procedure. The implant stability quotient (ISQ) that was obtained from Osstell Mentor was measured at the time of implantation and weekly over the first 8 weeks after implant placement. Implants stabilized more quickly without flap elevation than with flap elevation. For flapless implants, an increase in stability occurred after 2 weeks without a period of decreasing stability. However, for flap implants, a shift in implant stability from decreasing stability to increasing stability occurred after 2 weeks. In the canine model, flapless surgical placement of implants may increase the initial stability of implants compared with implants placed after the reflection of the mucoperiosteal flap.

Soil erosion rates on forested mountain hillslopes estimated using 137Cs and 210Pb ex

Although the excess of lead-210 ( 210Pb ex) has been described as an alternative or complementary nuclide to cesium-137 ( 137Cs) for soil erosion assessment, the potential use of 210Pb ex in forested environments has not been examined sufficiently. In this study, to investigate the potential use of 210Pb ex for the assessment of soil erosion on various forested hillslopes, we compared soil erosion rates derived from 210Pb ex to those from 137Cs obtained in forest stands. The study was conducted in four types of forest: a Japanese cypress stand with a bare forest floor, a Japanese cypress stand with a fern understory, a Japanese cedar stand with sufficient litter cover, and a natural broadleaf forested stand in the Tsuzura River basin of southeastern Japan. 137Cs and 210Pb ex inventories for seven potential reference sites on flat ridge tops and along transects in each stand were measured using gamma-ray spectrometry to calculate soil erosion rates. To describe the behavior of organic matter in each stand, the amounts of eroded sediment and organic matter were observed for approximately 2 years in erosion plots (1.7–2.0 m long, 0.5 m wide) in the Japanese cypress stand (bare), Japanese cedar stand, and broadleaf forest stand. From the preliminary assessment of potential reference sites, spatial variability in 210Pb ex was comparable to that of 137Cs. Mean erosion rates estimated from both Cs and Pb were highest in the Japanese cypress stand (bare), followed by the Japanese cypress stand (fern), the broadleaf forest stand, and the Japanese cedar stand. This magnitude relationship was consistent with that of observation results of eroded sediment in erosion plots. In the Japanese cypress stand (bare), a significant correlation was found between Cs- and Pb-based soil erosion rates in the Japanese cypress stand (bare) while no significance was found in the other three stands. These results provide evidence of the feasibility of 210Pb ex for soil erosion assessment in forest stands with bare forest floors. In the other three stands, the preferential loss of 210Pb ex associated with organic matter may explain the poor correlation between the two erosion rates.

Novel Application of Artificial Dermis Plus Autologous Vital Epithelial Cells: Improved Wound Epithelialization

The purpose of this study was to evaluate artificial dermis with the simultaneous addition of autologous epithelial cells for oral lesion defect reconstruction. Surgical wounds reconstructed with artificial dermis plus scraped epithelial cells were evaluated in 5 patients with oral benign lesions or squamous cell carcinoma. Clinical follow-up indices included scar formation and tissue surface texture observation. The neomucosal layers were analyzed histologically to establish the degree of epithelialization. Clinical observation showed that the oral mucosal texture was smoother in artificial dermis with added epithelial cells at 4 weeks postoperation compared with artificial dermis alone. The wound contraction and scar formation processes were slow. Viable epithelial cells with flat rete ridges remained in the artificial dermis, and a neoepithelial layer was present in the histological findings. We showed that healthy granulation tissue and neoepithelial formation in artificial dermis with epithelial cells was beneficial for the repair of oral defects. Scraping oral epithelial cells and applying them to artificial dermis assisted in the early preparation of composite grafts and minimized requirement for donor sites. This technique may improve the treatment of patients with oral benign tumors and early-stage squamous cell carcinoma.

Effects of soft tissue punch size on the healing of peri-implant tissue in flapless implant surgery

In an attempt to help produce guidelines for the use of soft tissue punches, this animal study was undertaken to examine the effects of soft tissue punch size on the healing of peri-implant tissue in a canine mandible model. Bilateral, edentulous, flat alveolar ridges were created in the mandibles of 6 mongrel dogs. After a 3-month healing period, 3 fixtures (diameter 4.0 mm) were placed on each side of the mandible using 3-mm, 4-mm, or 5-mm soft tissue punches. After subsequent healing periods of 3 weeks and 3 months, the peri-implant mucosa was evaluated using clinical, radiologic, and histometric parameters, which included gingival index, bleeding on probing, probing pocket depth, marginal bone loss, and vertical dimension measurements of the peri-implant tissues. The results obtained showed significant differences (P < .05) between the 3-mm, 4-mm, and 5-mm tissue punch groups for the length of the junctional epithelium, probing depth, and marginal bone loss at both 3 weeks and 3 months after implant placement. When the mucosa was punched with a 3-mm tissue punch, the length of the junctional epithelium was shorter, the probing depth was shallower, and less crestal bone loss occurred than when using a tissue punch with a diameter >or=4 mm. The results show that the size of the soft tissue punch plays an important role in achieving optimal healing. The findings support the use of a tissue punch slightly narrower than the implant itself to obtain better peri-implant tissue healing around flapless implants.

Testing proposed mechanisms for seafloor weakening at the top of gas hydrate stability on an uplifted submarine ridge (Rock Garden), New Zealand

We evaluate different hypotheses concerning the formation of a peculiar, flat-topped ridge at Rock Garden, offshore of the North Island of New Zealand. The coincidence of the ridge bathymetry with the depth at which gas hydrate stability intersects the seafloor has been previously used to propose that processes at the top of gas hydrate stability may cause seafloor erosion, giving rise to the flat ridge morphology. Two mechanisms that lead to increased fluid pressure (and sediment weakening) have previously been proposed: (1) periodic formation (association) and dissociation of gas hydrates during seafloor temperature fluctuations; and (2) dissociation of gas hydrates at the base of gas hydrate stability during ridge uplift. We use numerical models to test these hypotheses, as well as to evaluate whether the ridge morphology can develop by tectonic deformation during subduction of a seamount, without any involvement from gas hydrates. We apply a commonly-used 1D approach to model gas hydrate formation and dissociation, and develop a 2D mechanical model to evaluate tectonic deformation. Our results indicate that: (1) Tectonics (subduction of a seamount) may cause a temporary flat ridge morphology to develop, but this evolves over time and is unlikely to provide the main explanation for the ridge morphology; (2) Where high methane flux overwhelms the anaerobic oxidation of methane via sulphate reduction near the seafloor, short-period temperature fluctuations (but on timescales of years, not months as proposed originally) in the bottom water can lead to periodic association and dissociation of a small percentage of gas hydrate in the top of the sediment column. However, the effect of this on sediment strength is likely to be small, as evidenced by the negligible change in computed effective pressure; (3) The most likely mechanism to cause sediment weakening, leading to seafloor erosion, results from the interaction of gas hydrate stability with tectonic uplift of the ridge, provided bulk permeability strongly decreases with increasing hydrate content. Rather than overpressure developing from dissociation of hydrates at the base of gas hydrate stability (as previously thought), we found that the weakening is caused by focusing of gas hydrate formation at shallow sediment levels. This creates large fluid pressures and can lead to negative effective pressures near the seafloor, reducing the sediment strength.

Foliar Application of Glycinebetaine and Salicylic Acid Improves Growth, Yield and Water Productivity of Hybrid Sunflower Planted by Different Sowing Methods

Improved planting methods and foliar application of glycinebetaine (GB) and salicylic acid (SA) can improve the water productivity in field crops under limited water supply conditions. A 2-year field study was conducted to evaluate the possible role of different planting methods and foliar applications of GB and SA in improving the yield, quality and water productivity of hybrid sunflower (Helianthus annuus L.). The crop was planted by flat sowing (75 cm spaced rows) and ridge sowing (75 cm spaced ridges), with GB and SA applied exogenously at 100 and 0.724 mm, respectively, at both budding and flowering stages, while control plots received distilled water. Ridge sowing, rather than flat sowing, improved the biological yield, oil yield, leaf area index (LAI), crop growth rate (CGR), plant height, water-use efficiency and final achene yield during both the years. Foliar applications of GB and SA at both the stages improved the achene yield, although foliar application of GB at flowering was the most effective. Neither the planting methods nor the foliar application of GB and SA altered the achene oil contents during both the years. Foliar application of GB and SA increased the free proline content of the leaf and GB contents at flowering but reduced the achene protein contents, whereas planting method had no effect on these attributes across the years. Of the foliar applied chemicals, GB was more effective in improving sunflower growth and yield and water productivity than SA. To conclude, ridge sowing coupled with foliar application of GB at flowering stage could be beneficial for achieving maximum yields of hybrid sunflower under relatively water limited conditions in the field.

Ordered Si nanoaperture arrays for the measurement of ion currents across lipid membranes

Confined arrays of highly ordered microchannels in silicon with apertures as small as 100 nm and flat ridges between them are manufactured using electrochemically defined Si macropores whose orifices are reduced by deposition of dielectric SiOx thin films. The formation of continuous fluid lipid membranes over these channel arrays is achieved by vesicle fusion. This structure should allow a large choice of lipid membranes to be investigated by spatially resolved ion current measurements.

The Archaeology of the 16th And 17th Century Caddo in the Post Oak Savannah of Northeast Texas: The Tuinier Farm (41HP237), R. A. Watkins (41HP238), and Anglin (41HP240) Sites in the Stoots Creek Basin, Hopkins County, Texas

The Tuinier Farm (41HP237), R. A. Watkins (41HP238), and Anglin (41HP240) sites are 16th to 17th century Caddo sites in the modern-day Post Oak Savannah of Northeast Texas. All three of the sites are located on Stouts Creek, in the eastern part of Hopkins County, Texas, a northward-flowing tributary to White Oak Creek in the Sulphur River basin; the modern channel of White Oak Creek lies ca. 15 km north of these sites. The Culpepper site (41HP1), a previously investigated mid-to late 17th century Caddo habitation and cemetery site, is about 2 km downstream. Small areas of tall-grass prairie lie to the north between the Stouts Creek sites and White Oak Creek, but the eastern extent of the larger White Oak and Sulphur prairies is approximately 15 km to the west and northwest. At the time of the Caddo occupation of the Stouts Creek sites, the climate was wetter and warmer than today, with significant mesic periods between A.D. 1477- 1524, A.D. 1539-1572, and A.D. 1603-1670. After A.D. 1670, the years from A.D. 1671 -1676 were relatively cool and dry. The more mesic periods had more equitable rainfall (adequate growing season rainfall) and this, combined with the warmer temperatures, led to an increased net productivity and carrying capacity of plants and animals in the Post Oak Savannah and Pineywoods that were settled by Titus phase populations. The Tuinier Farm site is the closest of the three sites to the headwaters of Stouts Creek. It is situated on a relatively flat and sandy upland ridge (460 feet amsl) about 1 km south of the Anglin site and just east of Stouts Creek. Anglin is on a sandy knoll (460 feet amsl) on an upland slope, also east of Stouts Creek. The third site, R. A. Watkins, is 1.2 km northwest of the Anglin site, also on an upland slope, but 200 m east of an intermittent tributary to Stouts Creek and 1 km from Stouts Creek.

The neutral zone and vertical dimension of occlusion

More recent research points out to the existence of a new concept of the technique for locating the neutral zone. The objective of the study was to determine the effect of changing vertical dimension of occlusion, as well as that of the alveolar ridge type, on the neutral zone dimensions. The neutral zone was investigated in two groups of patients, with prominent (the control group) and flat alveolar ridges and it was determined for each patient at 3 heights (the correct, the increased and the decreased vertical dimension of occlusion). It was studied both vertically and horizontally. The width of the neutral zone was measured in different regions. The width of the neutral zone was minimal at the level of the occlusal plane, and it increased gradually as the occlusal plane went down and up, towards the anterior region. No statistically significant difference was found in the width of the neutral zone, between the group of patients with prominent alveolar ridges (the control group), and that with the flat ones. There was, also, no difference at all, at any level of the vertical dimension of occlusion, that could possibly bear statistical significance.

The vertical distribution of the root system of the desert highway shelterbelt in the hinterland of the Taklimakan Desert

In this work, the vertical distribution of the root system in the Tarim Desert Highway shelterbelt under high salinity water drip irrigation was investigated. The effect of site condition and shelterbelt age was studied. The root sample was collected by plant side soil column excavation. The root distribution was found to be dependent on soil texture, aspect, and plant age. In harden sand, the roots were mostly in the 0–40 cm soil. The root distribution is deep in flat sandy ground and ridge sand. In unit soil volume, the root weight of flat sandy ground was the highest. Compared with the shady slope, the sunny slope had much high total root weight, deeper root distribution, but less hair root. The root weight increased rapidly with the increase of the shelterbelt ages, and the most substantial increase was observed in the early years after forest implantation.

Blood vessels of the peri-implant mucosa: a comparison between flap and flapless procedures

The vascularity of a peri-implant tissue is a very important parameter in the establishment and maintenance of healthy tissue after dental implant insertion. The purpose of this study was to compare the vascularity of the peri-implant mucosa between flap and flapless implant surgeries by using a canine mandible model. In six mongrel dogs, bilateral, edentulated, and flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants were placed in each side by either flap or flapless procedure. After another healing period of 3 months, biopsies were obtained, prepared for light microscopy, and exposed to morphometric measurements. The supracrestal connective tissue lateral to the implant was found to be more richly vascularized in the flapless group than in the flap group. These results suggest that the flapless procedure may increase the vascularity of the peri-implant mucosa.

Morphogenesis of the peri-implant mucosa: a comparison between flap and flapless procedures in the canine mandible

Although it has been shown that the exclusion of the mucoperiosteal flap can prevent postoperative bone resorption associated with flap elevation, there have been only a few studies on the peri-implant mucosa following flapless implant surgery. The purpose of this study was to compare the morphogenesis of the peri-implant mucosa between flap and flapless implant surgeries by using a canine mandible model. In six mongrel dogs, bilateral edentulated flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants were placed in each side by either the flap or the flapless procedure. Three months after implant insertion, the peri-implant mucosa was evaluated by using clinical, radiologic, and histometric parameters, which included the gingival index, bleeding on probing, probing pocket depth, marginal bone loss, and the vertical dimension of the peri-implant tissues. The height of the mucosa, length of the junctional epithelium, gingival index, bleeding on probing, probing depth, and marginal bone loss were all significantly greater in the dogs that had the flap procedure than in those that had the flapless procedure (P < .05). These results indicate that gingival inflammation, the height of junctional epithelium, and bone loss around nonsubmerged implants can be reduced when implants are placed without flap elevation.

Discovery of the fourth species of the enigmatic chiroteuthid squid Asperoteuthis (Cephalopoda: Oegopsida) and extension of the range of the genus to the South Atlantic

A new species of deepwater squid Asperoteuthis nesisi is described based on a single specimen from the Southwest Atlantic. The new species is characterized by rather thin but muscled mantle and arms, and a wide ovoid funnel-locking apparatus with weak tragus and well-developed antitragus. Peculiar integumental tubercles are present both on the mantle and head. The largest arm suckers have chitinous rings with 12 –14 separate sharp triangular teeth distally and a flat thin ridge proximally. Based on the external morphology, A. nesisi n. sp. is more closely related to A. acanthoderma than to A. mangoldae. Two specimens of ‘Mastigoteuthis? A’ reported previously from waters of South Georgia probably belong to A. nesisi n. sp. Our finding extends the range of the genus Asperoteuthis from the tropical and temperate Pacific to the sub-Antarctic Atlantic, supporting a cosmopolitan distribution of this genus of deepwater squid.

Distribution and biomass transport of ice amphipods in drifting sea ice around Svalbard

Abstract Diversity and distribution of ice amphipods were determined in drifting sea ice around Svalbard during May–August 2003–2005. Sea-ice concentrations were determined visually and by satellite recordings. Backward trajectories for ice drift, based on satellite observations, indicated that multi-year ice in the area had originated 3–5 years earlier in the Kara Sea and western Laptev Sea, whereas some of the younger ice (1–2 years) may have originated in Franz Josef Land area. Quantitative collections of ice amphipods were obtained by SCUBA divers from flat areas and ridges below sea ice. The abundance and biomass were generally higher on ridges, particularly for the large Gammarus wilkitzkii, whereas Apherusa glacialis was more abundant on flat areas. Abundance and biomass varied among seasons (May–August) and years, with low values in May and higher values in July. The high values were similar to abundance and biomass values from July 1996. Redundancy analysis showed that 33% and 52% of the variability in respective species abundance and biomass could be explained by environmental variables, with ice draft and snow cover being the most important. The overall mean biomass for flats (0.30±0.05 g m−2) and ridges (1.64+0.46 g m−2) were used to calculate ice-associated biomass transport based on revised mean annual ice flux through Fram Strait (662,000 km2 yr−1) and into the Barents Sea (total 228,000 km2 yr−1). About 478×103 t WW (57×103 t C) of ice amphipods are transported annually through Fram Strait and 194×103 t WW (23×103 t C) into the northern Barents Sea, implying that 71% of the amphipod biomass in drifting sea ice passes through Fram Strait and 29% enters the Barents Sea. Climate induced reduction in ice thickness and extent will likely decrease this southward biomass transport, and thus the current carbon input of about 80×103 t C yr−1 into these marginal seas. Ice amphipod populations probably cannot be sustained if the summers become ice free in the Arctic Ocean, and particularly reduction of multi-year ice in the Arctic Ocean will affect long-lived species such as Gammarus wilkitzkii.