Journal articles: 'McMurdo Sound'

1

Parker, S. J., S. Mormede, S. M. Hanchet, A. Devries, S. Canese, and L. Ghigliotti. "Monitoring Antarctic toothfish in McMurdo Sound to evaluate the Ross Sea region Marine Protected Area." Antarctic Science 31, no. 4 (June 14, 2019): 195–207. http://dx.doi.org/10.1017/s0954102019000245.

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AbstractWe developed a random, stratified, vertical longline survey in McMurdo Sound, Antarctica, to compare the local age and size composition, diet and reproductive status of Antarctic toothfish (Dissostichus mawsoni) with those observed from a vessel-based survey of the southern Ross Sea shelf that includes a McMurdo Sound stratum. Results indicated that southern McMurdo Sound toothfish were larger and older than those a short distance away in northern McMurdo Sound. These data, in addition to recoveries of tagged fish, suggest that the large toothfish in McMurdo Sound may have limited mixing with the rest of the population. The potential effects of climate change and fishing in northern areas on toothfish abundance in McMurdo Sound will depend on the mechanism of toothfish recruitment to McMurdo Sound. Understanding the ecological relationships between McMurdo Sound toothfish and the larger population is required to predict these impacts. Furthermore, because toothfish predators (type C killer whalesOrcinus orca, Weddell sealsLeptonychotes weddellii) are abundant in the south-west margins of the Ross Sea, it is important to monitor toothfish in McMurdo Sound as part of the monitoring programme for the Ross Sea region Marine Protected Area.

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Cheng, Chen, Adrian Jenkins, Paul R. Holland, Zhaomin Wang, Chengyan Liu, and Ruibin Xia. "Responses of sub-ice platelet layer thickening rate and frazil-ice concentration to variations in ice-shelf water supercooling in McMurdo Sound, Antarctica." Cryosphere 13, no. 1 (January 29, 2019): 265–80. http://dx.doi.org/10.5194/tc-13-265-2019.

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Abstract. Persistent outflow of supercooled ice-shelf water (ISW) from beneath McMurdo Ice Shelf creates a rapidly growing sub-ice platelet layer (SIPL) with a unique crystallographic structure under the sea ice in McMurdo Sound, Antarctica. A vertically modified frazil-ice-laden ISW plume model that encapsulates the combined non-linear effects of the vertical distributions of supercooling and frazil concentration on frazil-ice growth is applied to McMurdo Sound and is shown to reproduce the observed ISW supercooling and SIPL distributions. Using this model, the dependence of the SIPL thickening rate and depth-averaged frazil-ice concentration on ISW supercooling in McMurdo Sound is investigated and found to be predominantly controlled by the vertical distribution of frazil concentration. The complex dependence on frazil concentration highlights the need to improve frazil-ice observations within the sea-ice–ocean boundary layer in McMurdo Sound.

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Parker, Steven J., Sophie Mormede, Arthur L. Devries, Stuart M. Hanchet, and Regina Eisert. "Have Antarctic toothfish returned to McMurdo Sound?" Antarctic Science 28, no. 1 (September 28, 2015): 29–34. http://dx.doi.org/10.1017/s0954102015000450.

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AbstractA dramatic reduction in catch rates of Antarctic toothfish in McMurdo Sound, Antarctica, has led to conclusions that the commercial bottom longline fishery for toothfish in the Ross Sea has drastically altered the toothfish population with cascading effects on the McMurdo Sound ecosystem. However, results from a new monitoring programme for Antarctic toothfish and other top predators carried out in McMurdo Sound in 2014 have shown toothfish catch rate, fish size and fish age similar to those observed prior to 2002. These results suggest that either large and old fish have returned to McMurdo Sound following a temporary environmentally driven absence or that they remained locally present but were not detected in the areas sampled. These findings highlight the importance of continued standardized monitoring for detecting the potential effects of fishing on the Ross Sea ecosystem.

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4

Christ, Andrew J., and Paul R. Bierman. "The local Last Glacial Maximum in McMurdo Sound, Antarctica: Implications for ice-sheet behavior in the Ross Sea Embayment." GSA Bulletin 132, no. 1-2 (May 2, 2019): 31–47. http://dx.doi.org/10.1130/b35139.1.

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AbstractDuring the Last Glacial Maximum (LGM), a grounded ice sheet filled the Ross Sea Embayment in Antarctica and deposited glacial sediments on volcanic islands and peninsulas in McMurdo Sound and coastal regions of the Transantarctic Mountains. The flow geometry and retreat history of this ice are debated, with contrasting views yielding divergent implications for the interaction between and stability of the East and West Antarctic ice sheets during late Quaternary time. Here, we present terrestrial geomorphologic evidence and reconstruct former ice-marginal environments, ice sheet elevations, and ice-flow directions in McMurdo Sound. Fossil algae in ice-marginal sediments provide a coherent radiocarbon chronology of maximum ice extent and deglaciation. We integrate these data with marine records to reconstruct grounded ice dynamics in McMurdo Sound and the western Ross Sea. The combined data set suggests ice flow toward the Transantarctic Mountains in McMurdo Sound during peak glaciation, with thick, grounded ice at or near its maximum position between 19.6 and 12.3 ka. Persistent grounded ice in McMurdo Sound and across the western Ross Sea after Meltwater Pulse 1a (14.0–14.5 ka) suggests that this sector of Antarctica did not significantly contribute to this rapid sea-level rise event. Our data show no significant advance of locally derived ice from the Transantarctic Mountains into McMurdo Sound during the local LGM.

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Dunbar, Robert B., Amy R. Leventer, and William L. Stockton. "Biogenic sedimentation in McMurdo Sound, Antarctica." Marine Geology 85, no. 2-4 (January 1989): 155–79. http://dx.doi.org/10.1016/0025-3227(89)90152-7.

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6

Leventer, Amy, and Robert B. Dunbar. "Diatom flux in McMurdo Sound, Antarctica." Marine Micropaleontology 12 (January 1987): 49–64. http://dx.doi.org/10.1016/0377-8398(87)90013-2.

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7

Talalay, Pavel G., and Alex R. Pyne. "Geological drilling in McMurdo Dry Valleys and McMurdo Sound, Antarctica: Historical development." Cold Regions Science and Technology 141 (September 2017): 131–62. http://dx.doi.org/10.1016/j.coldregions.2017.06.007.

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8

Gough, Alexander J., Andrew R. Mahoney, Pat J. Langhorne, Michael J. M. Williams, Natalie J. Robinson, and Tim G. Haskell. "Signatures of supercooling: McMurdo Sound platelet ice." Journal of Glaciology 58, no. 207 (2012): 38–50. http://dx.doi.org/10.3189/2012jog10j218.

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AbstractNear ice shelves around Antarctica the ocean becomes supercooled and has been observed to carry small suspended ice crystals. Our measurements demonstrate that these small crystals are persistently present in the water column beneath the winter fast ice, and when incorporated in sea ice they reduce the mean grain size of the sea-ice cover. By midwinter, larger ice crystals below the ice/water interface are observed to form a porous sub-ice platelet layer with an ice volume fraction of 0.25 ± 0.06. The magnitude and direction of the oceanic heat flux varied between (5 ± 6) Wm-2 (upwards) and (-15 ± 10) Wm-2 (downwards) in May, but by September it settled between (-6 ± 2) and (-11 ± 2) W m-2. The negative values imply that the ocean acts as a heat sink which is responsible for the growth of 12% of the ice thickness between June and September. This oceanic contribution should not be ignored in models of Antarctic sea-ice thickness close to an ice shelf.

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9

Harris, Colin M. "Protected areas review: McMurdo Sound, Ross Sea." Polar Record 30, no. 174 (July 1994): 189–92. http://dx.doi.org/10.1017/s0032247400024244.

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AbstractAs a result of new provisions in the Protocol on Environmental Protection to the Antarctic Treaty a number of countries are reviewing the management plans for protected areas in Antarctica. The United States and New Zealand have initiated a review of the 15 existing sites in the Ross Sea region, using an independent party, the International Centre for Antarctic Information and Research, to facilitate and coordinate the process. Management provisions are being revised to comply with the Protocol, and improved maps for the sites are being prepared using Geographical Information Systems. Visits in 1993/94 gathered field information, and thus far two sites have had new plans drafted: these are proceeding through the international review process. Input and comment is invited from interested parties with experience in these areas.

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10

Wells, Rufus M. G. "Respiration of Antarctic fish from McMurdo Sound." Comparative Biochemistry and Physiology Part A: Physiology 88, no. 3 (January 1987): 417–24. http://dx.doi.org/10.1016/0300-9629(87)90056-9.

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11

McGinnis, L. D., R. H. Bowen, J. M. Erickson, B. J. Allred, and J. L. Kreamer. "East-West Antarctic boundary in McMurdo sound." Tectonophysics 114, no. 1-4 (April 1985): 341–56. http://dx.doi.org/10.1016/0040-1951(85)90020-4.

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12

Knox, G. A., E. J. Waghorn, and P. H. Ensor. "Summer plankton beneath the McMurdo Ice Shelf at white Island, McMurdo Sound, Antarctica." Polar Biology 16, no. 2 (February 1996): 87–94. http://dx.doi.org/10.1007/bf02390428.

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13

Knox, G. A., Elspeth J. Waghorn, and Paul H. Ensor. "Summer plankton beneath the McMurdo Ice Shelf at White Island, McMurdo Sound, Antarctica." Polar Biology 16, no. 2 (January 12, 1996): 87–94. http://dx.doi.org/10.1007/s003000050032.

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14

Stevens, C. L., P. Sirguey, G. H. Leonard, and T. G. Haskell. "<i>Brief Communication</i> "The 2013 Erebus Glacier Tongue calving event"." Cryosphere 7, no. 5 (September 2, 2013): 1333–37. http://dx.doi.org/10.5194/tc-7-1333-2013.

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Abstract. The Erebus Glacier Tongue, a small floating glacier in southern McMurdo Sound, is one of the best-studied ice tongues in Antarctica. Despite this, its calving on the 27 February 2013 (UTC) was around 10 yr earlier than previously predicted. The calving was likely a result of ocean currents and the absence of fast ice. The subsequent trajectory of the newly created iceberg supports previous descriptions of the surface ocean circulation in southern McMurdo Sound.

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15

Stevens, C. L., P. Sirguey, G. H. Leonard, and T. G. Haskell. "<i>Brief communication</i> "The 2013 Erebus Glacier tongue calving event"." Cryosphere Discussions 7, no. 2 (April 25, 2013): 1749–60. http://dx.doi.org/10.5194/tcd-7-1749-2013.

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Abstract. The Erebus Glacier Tongue, a~small floating glacier in southern McMurdo Sound, is one of the best-studied ice tongues in Antarctica. Despite this, its calving on the 27 February 2013 (UTC) was around 10 yr earlier than previously predicted. The calving was likely a result of ocean currents and the absence of fast ice. The subsequent trajectory of the newly-created iceberg supports previous descriptions of the surface ocean circulation in southern McMurdo Sound.

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16

Testa, J. Ward. "Over-winter movements and diving behavior of female Weddell seals (Leptonychotes weddellii) in the southwestern Ross Sea, Antarctica." Canadian Journal of Zoology 72, no. 10 (October 1, 1994): 1700–1710. http://dx.doi.org/10.1139/z94-229.

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The movements and diving behavior of 18 adult female Weddell seals (Leptonychotes weddellii) were determined by satellite telemetry during the over-winter period in 1990 and 1991. Nine seals provided diving and movement data for 8 – 9 months. Seals that normally bred in the eastern part of McMurdo Sound spent most of the winter in the middle and northern parts of McMurdo Sound before the annual shore-fast ice had formed in those areas, or in the pack ice 0–50 km north of the sound and Ross Island. This is a greater use of pack ice, as opposed to shore-fast ice, in winter than was previously believed. Some long-distance movements (one over 1500 km in total) to the middle and northwestern parts of the Ross Sea also occurred. Although highly variable within and between individuals, dives indicative of foraging were primarily to mid-water regions (100 – 350 m) in both years, and were similar to those that have been observed in spring and summer, when Pleuragramma antarcticum is the primary prey of Weddell seals in McMurdo Sound.

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17

Winton, V. H. L., G. B. Dunbar, C. B. Atkins, N. A. N. Bertler, B. Delmonte, P. S. Andersson, A. Bowie, and R. Edwards. "The origin of lithogenic sediment in the south-western Ross Sea and implications for iron fertilization." Antarctic Science 28, no. 4 (February 26, 2016): 250–60. http://dx.doi.org/10.1017/s095410201600002x.

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AbstractSummer iron (Fe) fertilization in the Ross Sea has previously been observed in association with diatom productivity, lithogenic particles and excess Fe in the water column. This productivity event occurred during an early breakout of sea ice via katabatic winds, suggesting that aeolian dust could be an important source of lithogenic Fe required for diatom growth in the Ross Sea. Here we investigate the provenance of size-selected dust deposited on sea ice in McMurdo Sound, south-western (SW) Ross Sea. The isotopic signature of McMurdo Sound dust (0.70533<87Sr/86Sr<0.70915 and -1.1<εNd(0)<3.45) confirms that dust is locally sourced from the McMurdo Sound debris bands and comprises a two-component mixture of McMurdo Volcanic Group and southern Victoria Land lithologies. In addition, the provenance of lithogenic sediment trapped in the water column was investigated, and the isotopic signature (εNd(0)=3.9, 87Sr/86Sr=0.70434) is differentiated from long-range transported dust originating from South America and Australia. Elevated lithogenic accumulation rates in deeper sediment traps in the Ross Sea suggest that sinking particles in the water column cannot simply result from dust input at the surface. This discrepancy can be best explained by significant upwelling and remobilization of lithogenic Fe from the sea floor.

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18

Kellogg, Thomas B., Terry Hughes, and Davida E. Kellogg. "Late Pleistocene interactions of East and West Antarctic Ice-flow Regimes: evidence from the McMurdo Ice Shelf." Journal of Glaciology 42, no. 142 (1996): 486–500. http://dx.doi.org/10.3189/s0022143000003476.

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AbstractWe present new interpretations of deglaciation in McMurdo Sound and the western Ross Sea, with observationally based reconstructions of interactions between East and West Antarctic ice at the last glacial maximum (LGM), 16000, 12000, 8000 and 4000 BP. At the LGM, East Antarctic ice from Mulock Glacier split; one branch turned westward south of Ross Island but the other branch rounded Ross Island before flowing southwest into McMurdo Sound. This flow regime, constrained by an ice saddle north of Ross Island, is consistent with the reconstruction of Stuiver and others (1981a). After the LGM, grounding-line retreat was most rapid in areas with greatest water depth, especially along the Victoria Land coast. By 12000 BP, the ice-now regime in McMurdo Sound changed to through-flowing Mulock Glacier ice, with lesser contributions from Koettlitz, Blue and Ferrar Glaciers, because the former ice saddle north of Ross Island was replaced by a dome. The modern flew regime was established ∼4000 BP. Ice derived from high elevations on the Polar Plateau but now stranded on the McMurdo Ice Shelf, and the pattern of the Transantarctic Mountains erratics support our reconstructions of Mulock Glacier ice rounding Minna Bluff but with all ice from Skelton Glacier ablating south of the bluff. They are inconsistent with Drewry’s (1979) LGM reconstruction that includes Skelton Glacier ice in the McMurdo-Sound through-flow. Drewry’s (1979) model closely approximates our results for 12000-4000 BP. Ice-sheet modeling holds promise for determining whether deglaciation proceeded by grounding-line retreat of an ice sheet that was largely stagnant, because it never approached equilibrium flowline profiles after the Ross Ice Shelf grounded, or of a dynamic ice sheet with flowline profiles kept low by active ice streams that extended northward from present-day outlet glaciers after the Ross Ice Shelf grounded.

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19

Kellogg, Thomas B., Terry Hughes, and Davida E. Kellogg. "Late Pleistocene interactions of East and West Antarctic Ice-flow Regimes: evidence from the McMurdo Ice Shelf." Journal of Glaciology 42, no. 142 (1996): 486–500. http://dx.doi.org/10.1017/s0022143000003476.

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AbstractWe present new interpretations of deglaciation in McMurdo Sound and the western Ross Sea, with observationally based reconstructions of interactions between East and West Antarctic ice at the last glacial maximum (LGM), 16000, 12000, 8000 and 4000 BP. At the LGM, East Antarctic ice from Mulock Glacier split; one branch turned westward south of Ross Island but the other branch rounded Ross Island before flowing southwest into McMurdo Sound. This flow regime, constrained by an ice saddle north of Ross Island, is consistent with the reconstruction of Stuiver and others (1981a). After the LGM, grounding-line retreat was most rapid in areas with greatest water depth, especially along the Victoria Land coast. By 12000 BP, the ice-now regime in McMurdo Sound changed to through-flowing Mulock Glacier ice, with lesser contributions from Koettlitz, Blue and Ferrar Glaciers, because the former ice saddle north of Ross Island was replaced by a dome. The modern flew regime was established ∼4000 BP. Ice derived from high elevations on the Polar Plateau but now stranded on the McMurdo Ice Shelf, and the pattern of the Transantarctic Mountains erratics support our reconstructions of Mulock Glacier ice rounding Minna Bluff but with all ice from Skelton Glacier ablating south of the bluff. They are inconsistent with Drewry’s (1979) LGM reconstruction that includes Skelton Glacier ice in the McMurdo-Sound through-flow. Drewry’s (1979) model closely approximates our results for 12000-4000 BP. Ice-sheet modeling holds promise for determining whether deglaciation proceeded by grounding-line retreat of an ice sheet that was largely stagnant, because it never approached equilibrium flowline profiles after the Ross Ice Shelf grounded, or of a dynamic ice sheet with flowline profiles kept low by active ice streams that extended northward from present-day outlet glaciers after the Ross Ice Shelf grounded.

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Paulsen, Timothy S., Massimo Pompilio, Frank Niessen, Kurt Panter, and Richard D. Jarrard. "Introduction: The ANDRILL McMurdo Ice Shelf (MIS) and Southern McMurdo Sound (SMS) Drilling Projects." Geosphere 8, no. 3 (June 2012): 546–47. http://dx.doi.org/10.1130/ges00813.1.

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21

Paulsen, T., J. Encarnación, VA Valencia, JM Roti Roti, and C. Rasoazanamparany. "Detrital U–Pb zircon analysis of an Eocene McMurdo Erratic sandstone, McMurdo Sound, Antarctica." New Zealand Journal of Geology and Geophysics 54, no. 3 (September 2011): 353–60. http://dx.doi.org/10.1080/00288306.2011.582123.

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22

Buckley, Bradley A. "Rapid change in shallow water fish species composition in an historically stable Antarctic environment." Antarctic Science 25, no. 5 (March 12, 2013): 676–80. http://dx.doi.org/10.1017/s0954102013000114.

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AbstractMcMurdo Sound, Antarctica, is home to a unique marine biota with an ecology that has evolved in this frigid environment over millions of years. The region is one of the least disturbed, and possibly the last pristine, marine ecosystem on Earth. Here, the results of three seasons of fishing in the shallow nearshore waters of McMurdo Sound are reported. A shift in the composition of small fish species at one site, Inaccessible Island, has been observed in just five years. The shift in shallow water species composition occurred during a period that followed the maturation of a commercial fishery for the Antarctic toothfish, Dissostichus mawsoni Norman, a predator of smaller fish, and the presence of a large iceberg, termed B-15, at the mouth of McMurdo Sound during the early 2000s that trapped the annual sea ice in the area leading to the unusual accrual of multi-year sea ice. The data presented here provide a current record of species composition and physiological condition of small, shallow water fishes at three sites in McMurdo Sound, providing a current baseline for the assessment of future changes wrought by environmental changes and unprecedented fishery pressures in the Ross Sea.

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23

Jones, Stephen J., and Brian T. Hill. "Structure of sea ice in McMurdo Sound, Antarctica." Annals of Glaciology 33 (2001): 5–12. http://dx.doi.org/10.3189/172756401781818347.

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AbstractSea-ice cores from 11 sites in McMurdo Sound, Antarctica, were collected in 1982 and their crystallography examined. All but one were first-year sea ice. The cores, approximately 2 m long, consisted typically of a thin layer of granular or snow ice (approximately 0.1 m) followed by columnar-grained ice in the top metre and platelet ice in the bottom metre. Salinity and temperature measurements are reported. The columnar-grained ice usually had a strong preferred c-axis orientation in the horizontal plane and also showed a change in this preferred direction with depth in the ice. The mean c-axis orientation, however, usually aligned well with measured or implied currents in the Sound. The platelets were usually aligned with c axis horizontal or close to horizontal, and did not exhibit as marked a preferred orientation as the columnar-grained ice.

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Dayton, Paul K., and Kamille Hammerstrom. "A hagfish at Salmon Bay, McMurdo Sound, Antarctica?" Antarctic Science 30, no. 4 (June 11, 2018): 243–44. http://dx.doi.org/10.1017/s0954102018000202.

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25

Bernhard, J. M. "Foraminiferal biotopes in Explorers Cove, McMurdo Sound, Antarctica." Journal of Foraminiferal Research 17, no. 4 (October 1, 1987): 286–97. http://dx.doi.org/10.2113/gsjfr.17.4.286.

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MILLER, KATHY ANN, and JOHN S. PEARSE. "Ecological Studies of Seaweeds in McMurdo Sound, Antarctica." American Zoologist 31, no. 1 (February 1991): 35–48. http://dx.doi.org/10.1093/icb/31.1.35.

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Venkatesan, M. I., and F. H. Mirsadeghi. "Coprostanol as sewage tracer in McMurdo Sound, Antarctica." Marine Pollution Bulletin 25, no. 9-12 (January 1992): 328–33. http://dx.doi.org/10.1016/0025-326x(92)90691-x.

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Kim, Stacy, Ben Saenz, Jeff Scanniello, Kendra Daly, and David Ainley. "Local climatology of fast ice in McMurdo Sound, Antarctica." Antarctic Science 30, no. 2 (February 15, 2018): 125–42. http://dx.doi.org/10.1017/s0954102017000578.

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AbstractFast ice plays important physical and ecological roles: as a barrier to wind, waves and radiation, as both barrier and safe resting place for air-breathing animals, and as substrate for microbial communities. While sea ice has been monitored for decades using satellite imagery, high-resolution imagery sufficient to distinguish fast ice from mobile pack ice extends only back to c. 2000. Fast ice trends may differ from previously identified changes in regional sea ice distributions. To investigate effects of climate and human activities on fast ice dynamics in McMurdo Sound, Ross Sea, the sea and fast ice seasonal events (1978–2015), ice thicknesses and temperatures (1986–2014), wind velocities (1973–2015) and dates that an icebreaker annually opens a channel to McMurdo Station (1956–2015) are reported. A significant relationship exists between sea ice concentration and fast ice extent in the Sound. While fast/sea ice retreat dates have not changed, fast/sea ice reaches a minimum later and begins to advance earlier, in partial agreement with changes in Ross Sea regional pack ice dynamics. Fast ice minimum extent within McMurdo Sound is significantly correlated with icebreaker arrival date as well as wind velocity. The potential impacts of changes in fast ice climatology on the local marine ecosystem are discussed.

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Brett, Gemma M., Daniel Price, Wolfgang Rack, and Patricia J. Langhorne. "Satellite altimetry detection of ice-shelf-influenced fast ice." Cryosphere 15, no. 8 (August 26, 2021): 4099–115. http://dx.doi.org/10.5194/tc-15-4099-2021.

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Abstract. The outflow of supercooled Ice Shelf Water from the conjoined Ross and McMurdo ice shelf cavity augments fast ice thickness and forms a thick sub-ice platelet layer in McMurdo Sound. Here, we investigate whether the CryoSat-2 satellite radar altimeter can consistently detect the higher freeboard caused by the thicker fast ice combined with the buoyant forcing of a sub-ice platelet layer beneath. Freeboards obtained from CryoSat-2 were compared with 4 years of drill-hole-measured sea ice freeboard, snow depth, and sea ice and sub-ice platelet layer thicknesses in McMurdo Sound in November 2011, 2013, 2017 and 2018. The spatial distribution of higher CryoSat-2 freeboard concurred with the distributions of thicker ice-shelf-influenced fast ice and the sub-ice platelet layer. The mean CryoSat-2 freeboard was 0.07–0.09 m higher over the main path of supercooled Ice Shelf Water outflow, in the centre of the sound, relative to the west and east. In this central region, the mean CryoSat-2-derived ice thickness was 35 % larger than the mean drill-hole-measured fast ice thickness. We attribute this overestimate in satellite-altimeter-obtained ice thickness to the additional buoyant forcing of the sub-ice platelet layer which had a mean thickness of 3.90 m in the centre. We demonstrate the capability of CryoSat-2 to detect higher Ice Shelf Water-influenced fast ice freeboard in McMurdo Sound. Further development of this method could provide a tool to identify regions of ice-shelf-influenced fast ice elsewhere on the Antarctic coastline with adequate information on the snow layer.

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Bernardi, Giacomo, and Usha Goswami. "Molecular evidence for cryptic species among the Antarctic fish Trematomus bernacchii and Trematomus hansoni." Antarctic Science 9, no. 4 (December 1997): 381–85. http://dx.doi.org/10.1017/s0954102097000485.

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The notothenid species Trematomus bernacchii has previously been shown, by allozyme analysis, to be a complex of two cryptic species, one of which being more closely related to T. hansoni than to the other T. bernacchii cryptic species. Two T. bernacchii colour morphs, “white blotch” and “brown”, at McMurdo Sound, may correspond to these cryptic species. In this study, we present mitochondrial DNA sequences of the 12S and 16S ribosomal regions for six “white blotch” morphs, eight “brown” morphs collected in McMurdo Sound, one individual collected off the Antarctic Peninsula, and two T. hansoni individuals from McMurdo Sound. These sequences were compared with those of T. bernacchii and T. hansoni in the literature. Based on 14 phylogenetically informative sequences, no differences were found between “white blotch” and “brown” morphs. Furthermore, only one substitution separated these sequences from the previously published T. hansoni sequence, while 10 substitutions separated them from the previously published T. bernacchii sequence. Misidentified specimens, and sequence misreadings may be at the origin of these discrepancies. However, the presence of cryptic species within T. bernacchii and T. hansoni is not ruled out.

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HUNT, BEN M., KEVIN HOEFLING, and CHI-HING C. CHENG. "Annual warming episodes in seawater temperatures in McMurdo Sound in relationship to endogenous ice in notothenioid fish." Antarctic Science 15, no. 3 (September 2003): 333–38. http://dx.doi.org/10.1017/s0954102003001342.

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We obtained two years (1999–2001) of continuous, high resolution temperature and pressure data at two near-shore shallow water sites in McMurdo Sound, Ross Sea. Contrary to the long-held assumption of constant freezing conditions in the Sound, these records revealed dynamic temperature fluctuations and substantial warming during January to March reaching peak water temperatures of about −0.5°C. They also revealed that excursions above −1.1°C, the equilibrium melting point of ice in Antarctic notothenioid fish, totalled 8–21 days during the summer. Microscopic ice crystals are known to enter these fish but ice growth is arrested by antifreeze proteins. Prior to this study there were no known mechanisms of eliminating accumulated endogenous ice. The warm temperature excursions provide for the first time a possible physical mechanism, passive melting, for ice removal. The continuous records also showed a correlation between tidal pressures and cold temperature episodes, which suggests the influx of cold currents from under the Ross Ice Shelf may provide a mechanism for ice crystal nucleation as the source of the ice in McMurdo Sound fish. The accumulation of anchor ice on one logger caused it to float up which was recorded as a decrease in pressure. This is the first evidence for the time of onset of anchor ice formation in McMurdo Sound.

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Trenberth, Kevin E., and Jerry G. Olson. "Temperature Trends at the South Pole and McMurdo Sound." Journal of Climate 2, no. 10 (October 1989): 1196–206. http://dx.doi.org/10.1175/1520-0442(1989)002<1196:ttatsp>2.0.co;2.

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Foster, Brian A., and John C. Montgomery. "Planktivory in benthic nototheniid fish in McMurdo Sound, Antarctica." Environmental Biology of Fishes 36, no. 3 (March 1993): 313–18. http://dx.doi.org/10.1007/bf00001727.

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RIVKIN, RICHARD B. "Seasonal Patterns of Planktonic Production in McMurdo Sound, Antarctica." American Zoologist 31, no. 1 (February 1991): 5–16. http://dx.doi.org/10.1093/icb/31.1.5.

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Trodahl, H. J., M. J. McGuinness, P. J. Langhorne, K. Collins, A. E. Pantoja, I. J. Smith, and T. G. Haskell. "Heat transport in McMurdo Sound first-year fast ice." Journal of Geophysical Research: Oceans 105, no. C5 (May 15, 2000): 11347–58. http://dx.doi.org/10.1029/1999jc000003.

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36

Hopkins, T. L. "Midwater food web in McMurdo Sound, Ross Sea, Antarctica." Marine Biology 96, no. 1 (October 1987): 93–106. http://dx.doi.org/10.1007/bf00394842.

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37

Robinson, N. J., and M. J. M. Williams. "Iceberg-induced changes to polynya operation and regional oceanography in the southern Ross Sea, Antarctica, from in situ observations." Antarctic Science 24, no. 5 (May 14, 2012): 514–26. http://dx.doi.org/10.1017/s0954102012000296.

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AbstractTwo massive tabular icebergs calved from the Ross Ice Shelf in 2000 (B-15) and 2002 (C-19) and perturbed regional ocean processes for several years. Here we document the ocean's response in McMurdo Sound to the icebergs using in situ data collected before, during and after the icebergs’ residence in the Ross Sea. Departures from typical McMurdo Sound seasonal oceanography included the non-appearance of Antarctic Surface Water in summer, a cooler and more homogeneous water column during winter and ‘super-fresh’ High Salinity Shelf Water that gradually recovered its salinity. We found that each iceberg triggered a distinct response to regional ocean processes. B-15a, the largest piece of iceberg B-15, restricted surface circulation, cooled and freshened the upper water column and reduced melting near the ice shelf front for four years. Iceberg C-19 interrupted the operation of the Ross Sea polynya, from which McMurdo Sound took three to four years to recover, and was responsible for a geographic shift in the dense water formation region for the south-western Ross Sea. These results differ from earlier modelling studies and highlight the challenges of modelling the polar ocean. We also show that one pathway previously thought to supply dense water to the Ross Ice Shelf cavity was not operating at that time.

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Mager, Sarah M., Gregory H. Leonard, Andrew G. Pauling, and Inga J. Smith. "A framework for estimating anchor ice extent at potential formation sites in McMurdo Sound, Antarctica." Annals of Glaciology 56, no. 69 (2015): 394–404. http://dx.doi.org/10.3189/2015aog69a711.

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AbstractA distinctive feature of polar regions is the formation of ice clusters attached to the seabed, known as ‘anchor ice’. Anchor ice plays an important role in mobilizing bed sediments, and serves ecological roles providing habitats, or as an agent of disturbance creating potentially fatal environments to benthic fauna. The sublittoral zone associated with the landward margin represents the most likely environment for anchor ice formation, where conditions conducive to the advection of supercooled water from sub-ice-shelf cavities are favourable. We develop a framework to estimate the areal extent of anchor ice formation assuming a northerly flow of 75m deep supercooled water plumes from the Ross and McMurdo Ice Shelf cavities, Antarctica. In McMurdo Sound our results indicate that regions beneath the McMurdo Ice Shelf, extending along Brown Peninsula and White and Black Islands, are likely conducive to anchor ice formation. Anchor ice may also form along the Hut Point Peninsula and around Ross Island, and in pockets along the southern Victoria Land coast. The limitations of our approach include an imposed northerly flow of Ice Shelf Water, poorly constrained sub-ice-shelf bathymetry, and temporal variability in supercooled water depth production, particularly in the eastern Sound.

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39

Jeffries, M. O., W. F. Weeks, R. Shaw, and K. Morris. "Structural characteristics of congelation and platelet ice and their role in the development of antarctic land-fast sea ice." Journal of Glaciology 39, no. 132 (1993): 223–38. http://dx.doi.org/10.1017/s0022143000015884.

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AbstractIce cores were obtained in January 1990 from the land-fast ice in McMurdo Sound for a study of variations in texture, fabric, sub-structure, composition and development. Two primary ice types were observed, congelation and platelet, with a minor amount of frazil ice. Congelation ice growth precedes platelet-ice accretion. Congelation-ice fabrics show frequent moderate to strong alignments, a phenomenon believed to be due to water-current control of selective ice-crystal growth. Platelet ice originates at the base of the congelation ice, initially as a porous latticework of tabular ice crystals which subsequently consolidate by congelation of the interstitial water. Interstitial congelation-ice fabrics generally have little or no alignment, indicating the reduced effect of currents within the platelet latticework prior to solidification. Platelet-crystal textures range from small, wavy-edged forms to large, blade-like forms. Platelet-crystal fabrics indicate that, in addition to being randomly oriented, the platelet latticeworks commonly include many crystals with their flat (0001) faces oriented both parallel and normal to the base of the overlying ice. Plate-width data suggest that the interstitial congelation ice-growth rates remain similar to those of the overlying congelation ice. This effective increase in growth rates probably happens because the latticework of accumulating platelets ahead of the freezing interface ensures that the water within the platelet layer is at the freezing point and less heat has to be removed from platelet-rich water than from platelet-free water for a given thickness of congelation ice to grow. The negative oceanic heat flux associated with platelet-ice formation in McMurdo Sound explains why McMurdo Sound fast ice is thicker than Ross Sea pack ice, and also why it reaches a greater thickness than Arctic fast ice grown in a similar polar marine climate. Plate widths in the McMurdo Sound congelation ice suggest, however, that it grows no faster than Arctic congelation ice.

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Jeffries, M. O., W. F. Weeks, R. Shaw, and K. Morris. "Structural characteristics of congelation and platelet ice and their role in the development of antarctic land-fast sea ice." Journal of Glaciology 39, no. 132 (1993): 223–38. http://dx.doi.org/10.3189/s0022143000015884.

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AbstractIce cores were obtained in January 1990 from the land-fast ice in McMurdo Sound for a study of variations in texture, fabric, sub-structure, composition and development. Two primary ice types were observed, congelation and platelet, with a minor amount of frazil ice. Congelation ice growth precedes platelet-ice accretion. Congelation-ice fabrics show frequent moderate to strong alignments, a phenomenon believed to be due to water-current control of selective ice-crystal growth. Platelet ice originates at the base of the congelation ice, initially as a porous latticework of tabular ice crystals which subsequently consolidate by congelation of the interstitial water. Interstitial congelation-ice fabrics generally have little or no alignment, indicating the reduced effect of currents within the platelet latticework prior to solidification. Platelet-crystal textures range from small, wavy-edged forms to large, blade-like forms. Platelet-crystal fabrics indicate that, in addition to being randomly oriented, the platelet latticeworks commonly include many crystals with their flat (0001) faces oriented both parallel and normal to the base of the overlying ice. Plate-width data suggest that the interstitial congelation ice-growth rates remain similar to those of the overlying congelation ice. This effective increase in growth rates probably happens because the latticework of accumulating platelets ahead of the freezing interface ensures that the water within the platelet layer is at the freezing point and less heat has to be removed from platelet-rich water than from platelet-free water for a given thickness of congelation ice to grow. The negative oceanic heat flux associated with platelet-ice formation in McMurdo Sound explains why McMurdo Sound fast ice is thicker than Ross Sea pack ice, and also why it reaches a greater thickness than Arctic fast ice grown in a similar polar marine climate. Plate widths in the McMurdo Sound congelation ice suggest, however, that it grows no faster than Arctic congelation ice.

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41

Ainley, David G., Grant Ballard, Joseph T. Eastman, Clive W. Evans, Nadav Nur, and Claire L. Parkinson. "Changed prevalence, not absence, explains toothfish status in McMurdo Sound." Antarctic Science 29, no. 2 (November 29, 2016): 165–71. http://dx.doi.org/10.1017/s0954102016000584.

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AbstractWe comment on the conjecture by Parkeret al. (2016) that Antarctic toothfish recently returned to McMurdo Sound, arguing that this species never departed. Instead, as deduced from a 40-year fishing effort, toothfish water column prevalence became markedly reduced where bottom depths are <500 m, with research continuing to show their presence on the bottom or above the bottom where depths are deeper. We also counter arguments that toothfish departed, and remained absent, during and following a five-year presence of mega-icebergs residing near the opposite coast of Ross Island, the icebergs inhibiting or fomenting conditions that discouraged toothfish presence in the Sound. Available analyses reveal that toothfish movement into the Sound was probably not significantly affected, and additionally that neither changes in hydrography nor in primary productivity in the Sound would have been sufficient to impact toothfish presence through food web alteration. We hypothesize that the local effect of predation by seals and whales and the regional effect of a fishery targeting the largest toothfish (those neutrally buoyant and thus capable of occupying upper levels of the water column) has resulted in the remaining toothfish now being found predominantly closer to the bottom at greater depths.

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Guidetti, Marta, Stefania Marcato, Mariachiara Chiantore, Tomaso Patarnello, Giancarlo Albertelli, and Riccardo Cattaneo-Vietti. "Exchange between populations of Adamussium colbecki (Mollusca: Bivalvia) in the Ross Sea." Antarctic Science 18, no. 4 (November 14, 2006): 645–53. http://dx.doi.org/10.1017/s0954102006000678.

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The endemic Antarctic scallop Adamussium colbecki (Mollusca: Bivalvia) represents a key species in the Ross Sea littoral benthic ecosystem, locally reaching very high densities. This species has an annual gametogenic cycle, with a summer spawning event, and a pelagic larval behaviour. This paper aims at describing population structure and genetic polymorphism (using AFLP) of the large populations inhabiting the Ross Sea (Terra Nova Bay and McMurdo Sound) in order to investigate possible genetic exchange between A. colbecki in these areas. In Terra Nova Bay, size-frequency distributions show, generally, the dominance of large individuals, although site related differences are found in the abundance of smaller size classes (less than 40 mm), suggesting that recruitment is not a regular event. All McMurdo sites are characterized by large individuals and, at least during this sampling period, recruitment is completely absent. Nuclear DNA analyses show that the largest differences are found at the largest scale (between McMurdo Sound and Terra Nova Bay), but all populations sampled, even at a smaller spatial scale, have a well-settled genetic structure, notwithstanding the pelagic larval strategy. The panmixia hypothesis has therefore to be rejected for this species.

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Kyle, Philip R., and H. Lee Muncy. "Geology and geochronology of McMurdo Volcanic Group rocks in the vicinity of Lake Morning, McMurdo Sound, Antarctica." Antarctic Science 1, no. 4 (December 1989): 345–50. http://dx.doi.org/10.1017/s0954102089000520.

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Trachyandesite lava flows and trachytic dykes exposed at ‘Gandalf Ridge’ and near Lake Morning on the northern slopes of Mount Morning represent the oldest exposed volcanic rocks in the Erebus volcanic province of the McMurdo Volcanic Group. Conventional whole rock K-Ar age determinations show the rocks are mid-Miocene, ranging between 14.6 and 18.7 Ma. North–south trending faults, which parallel the Transantarctic Mountains, cut the dated dykes. The faults are probably part of a broad fault zone which bounds the uplifted Transantarctic Mountains and the down-dropped Ross Sea/Ross Ice Shelf embayment.

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44

Smith, Inga J., Patricia J. Langhorne, Timothy G. Haskell, H. Joe Trodahl, Russell Frew, and M. Ross Vennell. "Platelet ice and the land-fast sea ice of McMurdo Sound, Antarctica." Annals of Glaciology 33 (2001): 21–27. http://dx.doi.org/10.3189/172756401781818365.

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AbstractDendritic crystals of platelet ice appear beneath the columnar land-fast sea ice of McMurdo Sound, Antarctica. These leaf-like crystals are frozen into place by the advancing columnar growth. The platelets most probably begin to appear during July although in some parts of the Sound they may not appear at all. In addition, the amount and extent of platelet ice within the Sound varies from year to year. Previous authors have suggested that the formation of platelet ice is linked to the presence of the nearby ice shelf. It is a matter of debate whether these platelets form at depth and then float upwards or whether they grow in slightly supercooled water at the ice/water interface. The phenomenon is similar to that observed in the Weddell Sea region, but previous authors have suggested the two regions may experience different processes. This paper presents the results of field-work conducted in McMurdo Sound in 1999. Ice-structure analysis, isotopic analysis and salinity and temperature measurements near the ice/water interface are presented. Freezing points are calculated, and the possible existence of supercooling is discussed in relation to existing conjectures about the origin of platelets.

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45

Kooyman, Gerald. "Animal-Borne Instrumentation Systems and the Animals that Bear Them: Then (1939) and Now (2007)." Marine Technology Society Journal 41, no. 4 (December 1, 2007): 6–8. http://dx.doi.org/10.4031/002533207787441935.

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The history of animal-borne instrumentation is reviewed from the first basic depth gauge invented in the late 1800s, to the complex animal-borne imagery and archival systems of the present day. A major breakthrough occurred in 1964 when the first time-depth recorder was deployed on a Weddell Seal in McMurdo Sound, Antarctica. The next phase in the study of animals at sea was the use of microprocessors as archival recorders in the mid-1980s. These also were first attached to Weddell seals in McMurdo Sound. Microprocessor technology made possible the next major step of attaching a video camera housed in a submersible case (Crittercam) to a loggerhead turtle. Since the 1990s the field of “Biologging” has flourished, with new additions of satellite and GPS tracking, and resulted in three major international symposiums in the past four years (2003-2007).

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46

Putt, M., G. Miceli, and DK Stoecker. "Association of bacteria with Phaeocystis sp. In McMurdo Sound, Antarctica." Marine Ecology Progress Series 105 (1994): 179–89. http://dx.doi.org/10.3354/meps105179.

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47

Chinn, T. J. "Recent fluctuations of the Dry Valleys glaciers, McMurdo Sound, Antarctica." Annals of Glaciology 27 (1998): 119–24. http://dx.doi.org/10.3189/1998aog27-1-119-124.

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The state of equilibrium of the frontal positions of the glaciers of the Dry Valleys area of McMurdo Sound, Antarctica, has heen a subject of speculation since the) were fu si seen. A programme to measure the changes in frontal positions of 12 ice-cliffed glaciers has been maintained since 1982-83, with a 30 year record for Mcscrve Glacier. Simple taped distances from fixed points to the fronts of the glaciers have demonstrated that, in proportion to their flow and ablation regimes which are two orders of magnitude slower than those of temperate glaciers, the glaciers are fluctuating as dynamically as do temperate glaciers. Maximum advance or recession rates have been found to be near ±1 m a−1, changes which are almost undetectable in comparative photographs. Recession was found to be the dominant change trend, with yearly variations reflecting changes in annual ablation.The total height of the ice cliff gives a ready estimation of glacier equilibrium, with cliff heights being greatest on advancing glaciers. The division between advancing and receding glaciers was found to be at a cliff height of about 25 m.

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Dayton, Paul K., Kamille Hammerstrom, Shannon C. Jarrell, Stacy Kim, Walter Nordhausen, D. J. Osborne, and Simon F. Thrush. "Unusual coastal flood impacts in Salmon Valley, McMurdo Sound, Antarctica." Antarctic Science 28, no. 4 (May 6, 2016): 269–75. http://dx.doi.org/10.1017/s0954102016000171.

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AbstractLarge floods bringing significant sediments into the coastal oceans have not been observed in Antarctica. We report evidence of a large flood event depositing over 50 cm of sediment onto the nearshore benthic habitat at Salmon Bay, Antarctica, between 1990 and 2010. Besides direct observations of the sedimentation, the evidence involves a debris flow covering old tyre tracks from the early 1960s, as well as evidence of a considerable amount of sediment transported onto the Salmon Creek delta. We believe that the flood was sourced from the Salmon Glacier and possibly the smaller Blackwelder Glacier. Such floods will be more common in the future and it is important to better understand their ecological impacts with good monitoring programmes.

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Hendy, Chris H. "Late quaternary lakes in the mcmurdo sound region of antarctica." Geografiska Annaler: Series A, Physical Geography 82, no. 2-3 (August 1, 2000): 411–32. http://dx.doi.org/10.1111/j.0435-3676.2000.00131.x.

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Hendy, Chris H. "Late Quaternary Lakes in the McMurdo Sound Region of Antarctica." Geografiska Annaler, Series A: Physical Geography 82A, no. 2&3 (October 2000): 411–32. http://dx.doi.org/10.1111/1468-0459.00131.

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Journal articles on the topic 'McMurdo Sound'

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