The IceCube Neutrino Observatory is the largest neutrino detector in the world, located at the geographic South Pole. The detector consists of 86 cables called “strings”, each instrumented with 60 sensors. IceCube has observed high energy neutrinos from beyond the solar system, including the highest energy neutrinos ever observed and a neutrino in coincidence with a flaring blazar. IceCube...
Modeling of optical properties of ice at the South Pole, as it applies to neutrino detectors AMANDA and IceCube, has a long history of incremental improvements and unexpected surprises, starting in the early 90s, with significant breakthroughs still happening within the last couple of years. The ice model is used by the IceCube collaboration in both simulating and reconstructing of the IceCube...
It has been 4 years since the completion of the SPICEcore project in the field. The SPC14 ice
core was drilled to a final depth of 1751 m and the measurements funded with the first wave of
science proposals have already been completed. More than half of the SPC14 ice core is
archived at the NSF ice core facility in Denver and will be available for future measurements for
years to come. The...
Slides available at: https://epic.awi.de/id/eprint/53548/
The Antarctic geothermal heat flux (GHF) has significant influence on the viscosity of basal ice and meltwater content at the ice–base interface. To evaluate GHF under the Antarctic Ice Sheet at South Pole, we used available temperature profile taken by AMANDA and IceCube thermistors installed at depths from 800 m to 2445 m in boreholes produced with hot-water drilling. We applied...
The South Pole is at least 180 km from an ice-flow divide. Thus, the annual-equivalent layer thicknesses in the area are affected by spatial variations in accumulation upstream in addition to temporal variations in regional accumulation. We use a new method to compare the accumulation record from the South Pole Ice Core (SPICEcore), derived by correcting measured layer thicknesses for...
Despite major advances in subglacial bed topography mapping over the past decades using nadir-looking radar sounding profiles, significant sectors remain poorly known and critical spatial details are missing, especially in the proximity of grounding lines. We present a novel, high-resolution, physical description of Antarctic bed topography and ice thickness that uses a mass conservation...
Given the vast distance to bedrock and to the nearest outcrop, it seems justified to assume that the ice shelf flow regime at South Pole is uniform within the footprint of the Station. However, survey suggest otherwise.
The search for a new environmentally friendly low-temperature drilling fluid for deep drilling in ice is one of the most pressing tasks. ESTISOL 140 was identified as the most suitable fluid and has recently been used in several ice drilling projects, for example, SPICEcore project at South Pole. Unfortunately, no new progress has been made in identifying new drilling fluids. While ESTISOL 140...
The IceCube Enhanced Hot Water Drill (EHWD) is being refurbished and put back in service to drill holes for the a 7 hole IceCube Upgrade. A preliminary redesign of that system using microturbines, low pressure water heating, high pressure pumping of hot water, and larger sleds is underway to prepare for a potential GEN2 drilling program with 120 holes. Special attention to changes in the...
The British Antarctic Survey (BAS) has developed a larger diameter (~285mm) version of the record-breaking Rapid Access Isotope Drill (RAID) known as BigRAID. The increase in size brings new design challenges but also new opportunities. The drill is described alongside the modifications to the RAID design, data from increased diameter drilling and the pre-deployment testing regime.
BigRAID...
In 2013 the dust logger was equipped with a precision orientation sensor to study ice anisotropies. This sensor can be used to monitor SPICE borehole deformation by comparing data taken over multiple seasons between 2015 and 2019. We will also re-examine data from inclinometers installed in the IceCube array in order to develop a fuller picture of ice flow at South Pole.
An acoustic televiewer, which collects tilt, azimuth, and
high-resolution caliper measurements, was deployed to measure the 3D shape of the 1751m SPIceCore Borehole in December 2019. We will present the results of this data collection including analysis of borehole shape and inclination, evidence of drilling artifacts on
the borehole wall, and lessons learned for optimal data collection...
Analyses of the physical properties of the 1751-meter long South Pole ice core (SPC14) have been carried out on 82 vertically-oriented samples cut from the core below the firn-ice transition on a 20-meter sampling interval. Analyses include bubble-number density, grain orientation and fabric, grain-size distributions, and grain-shape characteristics derived from the grain statistics.
We...
Microparticle measurements from Antarctic ice cores provide valuable information on past climate dynamics (e.g., atmospheric circulation, dust source area conditions) and ice physical properties. Microparticle concentration and size distributions can be measured using coulter counter techniques on discrete samples, and/or high-resolution laser-based (Abakus) particle counters paired with...
The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole with 5160 photomultipliers to detect Cherenkov light of charged relativistic particles. The experiment pursues a wide range of scientific questions ranging from particle physics such as neutrino oscillations to astronomy with the search for sources of astrophysical neutrinos. Most of...
We report on the observation of a directional anisotropy in the recorded intensity of back-scattered light as measured using an oriented laser dust logger. The measurement has been performed in a drill hole at the geographic South Pole, about a kilometer away from the IceCube Neutrino Observatory. The drill hole was preserved for logging access, after the SPICEcore collaboration had retrieved...
Ice-penetrating radar is able to detect anisotropy through exploiting the birefringence of ice crystals, and this technique has aided quantification of the horizontal properties of the ice crystal orientation fabric (COF) at multiple sites across the Antarctic Ice Sheet. These techniques have not only been verified through multiple comparisons with ice cores, but also have been subsequently...
The climatic conditions over ice sheets at the time of snow deposition imprint distinctive crystallographic properties to the resulting ice. As it gets buried, its macroscopic structure evolves due to vertical compression and horizontal extension but retains traces of the climatic imprint that generate distinctive mechanical, thermal and optical properties. Because climate alternates between...
The IceCube-Gen2 radio array is an ambitious augmentation to IceCube-Gen2, seeking to extend the ultra-high energy neutrino detection reach above 10 PeV. Consisting of 200 multi-channel 'stations' deployed over a surface area of ~500 km^2, such an array also offers significant radioglaciological science. We'll summarize plans to calibrate South Polar radio ice properties necessary for neutrino...
Seismograms from the South Pole have been important for seismological observations for over six decades by providing (until 2007) the only continuous seismic records from the interior of the Antarctic continent. The station SPA (South Pole, Antarctica) has undergone many updates over the years including being converted to a digitally recording station as part of the Global Seismographic...
IceCube showed that dustloggers deployed in freshwater boreholes provide highly detailed Antarctic histories for mapping chronology across the continent and Southern Ocean. Developed over the same time, the Ice Diver cryobot has proven potential for realizing a deep Philberth probe to explore ice anywhere with a small logistic footprint. The two technologies can be united naturally, and an...
Developed and applied to ice masses over the past decade, borehole optical televiewing (OPTV) is a logging technique that records a geometrically accurate, full-colour (radial) image of the complete borehole wall at a typical resolution of 1 mm. Borehole OPTV has been successfully deployed at temperate and polythermal valley glaciers, at Antarctic ice shelves, and at the Greenland Ice Sheet –...
Ice boreholes have been shown to be stable for several decades, if filled with a non-freezing fluid that has the same density as ice. This enables repeated observations and occupations by instrumented probes, making long time-series measurements possible. We recently learned that Gen-2 is exploring the possibility of such a long-term access hole for calibration purposes.
Our new Rapid...
