Redescription of two rare, deep-sea species of hyperiidean amphipod, Lanceola loveni antarctica Vinogradov, 1962 and L. sphaerica Vinogradov, 1970 (Crustacea: Amphipoda: Hyperiidea: Lanceolidae)

Lanceola loveni antarctica and L. sphaerica are rare deep-sea species known from very few specimens. Until recently (Zeidler 2019) L. loveni antarctica was known only from the types, seven specimens (7–27 mm), from the Indian Ocean Sector of the Antarctic (Vinogradov 1962). Similarly, L. sphaerica, originally described as a variety of L. clausi (Vinogradov, 1957), based on two damaged specimens, a female (8.0 mm) and a male (9 mm), from the Kurile-Kamchatka region of the NW Pacific, later elevated to full species status by Vinogradov (1970) upon the discovery of a well-preserved male (5 mm) from the same general region, was until then known only from these three specimens. The recent discovery of several specimens of both species in the USNM (Zeidler 2019) has now made it possible to provide a more detailed redescription of these rare species, including some new distribution records.

Excess ice loads in the Indian Ocean sector of East Antarctica during the last glacial period

An accurate reconstruction of the Antarctic Ice Sheet is essential in order to develop an understanding of ice-sheet responses to global climate changes. However, the erosive nature of ice-sheet expansion and the difficulty of accessing much of Antarctica make it challenging to obtain field-based evidence of ice-sheet and sea-level changes before the Last Glacial Maximum. Limited sedimentary records from Lützow-Holm and Prydz Bays in East Antarctica demonstrate that the sea level during Marine Isotope Stage 3 was close to the present level despite the global sea-level drop lower than –40 m. We demonstrate glacial isostatic adjustment modeling with refined Antarctic Ice Sheet loading histories. Our experiments reveal that the Indian Ocean sector of the Antarctic Ice Sheet would have been required to experience excess ice loads before the Last Glacial Maximum in order to explain the observed sea-level highstands during Marine Isotope Stage 3. As such, we suggest that the Antarctic Ice Sheet partly reached its maximum thickness before the global Last Glacial Maximum.

Supplemental Material: Excess ice loads in the Indian Ocean sector of East Antarctica during the last glacial period

Sea-level dataset and glacial isostatic adjustment modeling results.<br>

Supplemental Material: Excess ice loads in the Indian Ocean sector of East Antarctica during the last glacial period

Sea-level dataset and glacial isostatic adjustment modeling results.<br>

Oceanographic features of the Indian Ocean sector of Coastal Antarctica (Short Communication)

A review is presented on physical oceanographic features based on expendable CTD data collected in the Indian Ocean sector of the Southern Ocean. The thermohaline structure is dominated by Circumpolar Deep Water. The temperature and salinity are affected by cyclonic circulation in the Weddell Sea and Prydz Bay. High chlorophyll-a blooms (2-4 mg m-3) evolve during austral summer due to stratification which is caused by freshwater generated from the sea ice melt and the glacial outflow which traps phytoplankton in a shallow mixed layer, where they are exposed to higher irradiances of photosynthetically active radiation. Attempts have been made to relate the physical characteristics to biomass inferred from data published from previous Indian Scientific expeditions. More in-situ observations related to biophysical and chemical are recommended in the near future projects.