Expedition log by MBARI Senior Scientist Aaron Micallef

As our MBARI activities draw to a close, we have crossed into the Chukchi Sea, reaching as far north as 77°N before beginning our southward journey. This marks the start of the next phase of the expedition, which will continue under the leadership of our colleagues from KOPRI. From here, we will gradually make our way toward Dutch Harbor, Alaska, our final destination, where we will disembark and bring this journey to an end.

Ice cover meant we could not complete our original plan, forcing us to shift our efforts further west and closer inshore. Yet these adaptations provided opportunities for science we might not otherwise have pursued. We deployed the autonomous underwater vehicle (AUV), MiniROV, and controlled source electromagnetic (CSEM) system multiple times. A particular highlight was repeat AUV mapping of the seafloor along the western flank of the Mackenzie Trough, which revealed striking changes since surveys were conducted a decade ago. These differences guided MiniROV operations with CoMPAS Lab tools, enabling centimeter-scale mapping, push core sampling, and even successful ice drilling. Additional gravity cores and CTD casts expanded the scope of our datasets.

Beyond the science, the Arctic continued offering breathtaking sunsets that lit the horizon during our long northern days.

With MBARI’s work now complete, we leave this leg of the expedition with a wealth of new insights and experiences, and look forward to seeing what discoveries the coming days with KOPRI will bring.