Mission: Pine Island Glacier 5
Priority: Baseline
 
With clouds entering the Amundsen Sea Embayment from both the east and west over the coming days, IceBridge made the challenging decision to attempt the baseline priority Pine Island Glacier 5 mission.  The window was closing, and with all the forecasts in agreement that the clear skies over Pine Island would only last until the end of the survey time, the PIG 5 mission was a difficult choice, especially in absence of any recent imagery over the glacier.  Almost entirely as expected, IceBridge encountered blue skies over nearly the entire mission, with spare high clouds creeping in towards the end of the survey.
 
The recently calved iceberg, B-46, stole the show.  With several tracks focused along PIG’s main ice trunk, all on board were treated to several glimpses of the massive iceberg.  B-46 could not be viewed in its entirety at 1500’ due to its shear size, but the series of giant rifts and cliff faces were unlike anything most on board had seen.  The ATM team measured cliff heights between 50 and 65 meters while MCoRDS measured iceberg thicknesses of approximately 500 meters! It is extremely impressive watching the instrument teams provide measurements in real time.
      
The PIG 5 is a legacy baseline IceBridge mission, so it was not modified to fly any ICESat-2 tracks in order preserve the long time series over several flight tracks. All instruments reported excellent data quality and 100% data collection.
 
Media: A writer, Brian Howard, and photographer, Thomas Prior, from National Geographic flew with IceBridge today.
 
Outlook: As the clouds slowly creep into West Antarctica from east and west, flight selection over the next few days ill likely be a challenge for IceBridge.  As always, the team will do its best to attempt flights of highest priority, weather permitting.
 
List of attached figures:

1. Map of today’s science mission. (John Sonntag/NASA)
2. A view from the ATM T-6 wide scan of the giant rift separating B-46 from the Pine Island Ice Shelf.  Cliff height is more than 70 meters above the ocean surface. (Matt Linkswiler/NASA)
3. Icebergs from the Stange Ice Shelf (lower left corner) mingle with snow covered sea ice floes. (Brooke Medley/NASA)
4. Close up of the B-46 cliff face; evidence of cliff failure (toppled blocks on the right). (Brooke Medley/NASA)
5. Enormous curved crevasses near the Pine Island Glacier shear margin. (Brooke Medley/NASA)
6. The DC-8’s shadow is dwarfed in scale by the B-46 iceberg. (Brooke Medley/NASA)
7. A view of the main rift looking to the south. (Brooke Medley/NASA)
8. A view of the main rift looking to the north. (Brooke Medley/NASA)