Antarctic Ice Core Crystal Orientation and Grain Size Measurements

185 thin sections from the 1195.9-meter Dome Summit South ice core drilled between 1987 and 1993. The Australian Antarctic Division collected c-axis orientation and grain size data from depths between 117m and 1196m, with a median of 100 c-axis orientations per section. This dataset provides crystallographic measurements for studying ice sheet dynamics and history.

Use Cases

• Analyze ice fabric evolution with depth by correlating `colatitude` and `azimuth` measurements with `depth_ice_equivalent`.
• Model ice flow anisotropy by calculating orientation tensors (`orientation_tensor_a`, `orientation_tensor_V`) from c-axis vectors (`c_cartesian` or `c_polar`).
• Investigate grain growth processes by examining the relationship between `mean_horz_grain_area` and `depth_actual` across different `section_orientation` types.
• Assess sample density and statistical reliability by filtering sections based on the `number_of_c_axes` field, which ranges from 5 to 111.
• Map the spatial provenance of core samples using the fixed `latitude` and `longitude` coordinates for geographic context in regional studies.

Strengths

• Contains data from 185 individual thin sections, providing multiple samples for analysis.
• Offers high-resolution crystallographic data with a median of 100 c-axis orientation measurements per section.
• Covers a significant depth profile from 117m to 1196m, capturing a long temporal record within the ice core.

Limitations

• Sample size per section varies widely, from 5 to 111 c-axis orientations, which may affect statistical robustness for sections with low counts.
• Data collection ended in 1993, making the record temporally stale for contemporary ice sheet dynamics.
• Geographic coverage is limited to a single ice core location at Law Dome, limiting broader regional generalizations.

Provenance

Source

Australian Antarctic Division (AU_AADC) via NASA EarthData.

Collection Method

Measurements from thin sections of ice core samples drilled at the Dome Summit South site.

Time Range

Ice core spans a historical climate record; physical sampling occurred between 1987 and 1993.

Freshness

Data reflects a snapshot from the core drilling period (1987-1993) with no stated updates.

Geography

Dome Summit South ice core, Law Dome, East Antarctica (66.770°S, 112.80°E).