Southeast Alaska stands as a testament to glaciers’ immense power and beauty, sculpting its rugged landscapes over millennia. The region’s iconic icy giants are the North and South Sawyer, LeConte, and Baird Glaciers, each weaving a unique tale of geological history and environmental change.

A Journey Through Time: Glacial Formation and Dynamics

 

What is the Last Glacial Maximum?

 

At the peak of the last glacial maximum somewhere between 19,00 and 26,000 years ago, Southeast Alaska was blanketed in ice. The tidewater glaciers we see today, like many others in the region, reached their maximum advancement during this period, carving long winding fjords and shaping steep mountain peaks, creating the incredible landscape that is Southeast Alaska today. 

As these glaciers retreated into the fjords they carved, they left behind a vast barren landscape, creating a blank canvas for Alaska’s plant population to evolve and thrive. This evolution of plant growth can still be seen today along the more recently exposed walls of the fjords where glacial ice only recently receded and plant growth has just begun. Traveling deep into the fjords provides an experience akin to traveling back in time, getting to witness the early stages of vegetation starting to inhabit the barren landscape left behind by receding glaciers.  

Southeast Alaska’s Tidewater Glaciers Today

 

South Sawyer Glacier

Located in the Tracy Arm-Fords Terror Wilderness, South Sawyer Glacier is popular for its stunning blue ice and dramatic calving events. Calving occurs when chunks of ice break off the glacier, crashing into the water below with a thunderous roar. 

This glacier is actively monitored for its retreat and melt rates, providing valuable insights into current climate trends. South Sawyer Glacier has receded roughly 1300 annually over the last 100 years, creating a vast ice-field at the face of the glacier made up of chunks of ice ranging from the size of a baseball all the way up to icebergs larger than the MV Northern Song!

The vast ice field of South Sawyer Glacier creates the perfect breeding grounds for harbor seals to give birth to their pups. Harbors seals from all over Southeast Alaska make the long trek into Tracy Arm in the late spring and early summer to give birth to their pups on icebergs safe from predators such as killer whales and bears. They raise their pups on the icebergs and in the surrounding fjord waters until it is safe to return to their typical habitat along the shores of rocky islands and sandy beaches throughout Alaska. 

North Sawyer Glacier

Just six miles northwest of South Sawyer Glacier, North Sawyer Glacier has receded into a relatively narrow and shallow portion of the fjord, stabilizing the face of the glacier and causing any calving to cease. The glacier’s shallow water and gradual movement have resulted in the accumulation of glacial till at the foot of the glacier, creating what is known as a recessional moraine. 

Moraines are significant accumulations of unconsolidated rock and debris deposited by glaciers. The primary moraines seen in Southeast Alaska are recessional and terminal. Recessional moraines, like the one North Sawyer Glacier rests on today, are small ridges of rock and debris created when a glacier pauses during its retreat, and debris previously frozen in the glacier’s leading edge is deposited along the foot of the glacier. Terminal moraines are prominent ridges of debris pushed forward by the leading edge of a glacier and dumped at the farthest-reaching point of the glacier’s advance. During the last glacial epoch, Sawyer glacier reached out to the mouth of Tracy Arm forming a massiver terminal moraine that can be witnessed today in the form of a shallow bar that must be crossed when entering Tracy Arm. Many other Glaciers in the area have the same shallow entrance to their fjords created by a terminal moraine, including Baird Glacier in Endicott Arm and LeConte Glacier.

LeConte Glacier 

16 miles from the M/V Northern Songs home-port of Petersburg, Alaska, sits LeConte Glacier, the southernmost tidewater glacier in the northwest hemisphere. 

Like South Sawyer Glacier, Leconte Glacier is actively calving off large icebergs into the surrounding waters of LeConte Bay, creating a vast ice field perfect for harbor seals to give birth to their pups. 

LeConte Glacier has been meticulously studied by students from Petersburg High School since 1983. Every year, they take the much-anticipated trip from Petersburg to LeConte Bay to examine the location of the glacier’s terminus, resulting in one of the longest ongoing studies of a single glacier. Captain Harley Ethelbah also participated in these studies in high school. 

Various organizations have conducted numerous other studies over the years to understand the tidewater glacier cycle better. Information collected from studying Leconte Glacier has provided significant insight into glacial studies worldwide. 

Baird Glacier

Located 16 miles north of Petersburg, Baird Glacier reaches down from the vast Stikine ice field into the head of Thomas Bay. For over 100 years, Baird Glacier rested on a terminal moraine, allowing visitors to climb onto it and the glacier. In some cases, it even acted as the starting point for mountaineers attempting to ascend Devil’sThumb, an iconic mountain peak 15 miles east of the glacier.

Over the years, the glacier continually lost volume, helping to initiate the break up of the terminus in 2015 when a glacial flood starting in the upper reaches of the glacier caused the already thinning terminus of the glacier to slowly break, sending icebergs into Thomas Bay. As the terminus receded from its terminal moraine, it left behind a large mud flat that was filled with runoff from the glacier, creating a lake at the new terminus of the glacier. Accessible at high tide skiff from our 8-day yacht cruise, Baird Glacier still allows visitors to enjoy the beautiful landscape and unique characteristics it has to offer.

 

Conclusion

Southeast Alaska glaciers are more than just stunning natural wonders; they are vital components of the region’s ecosystem, culture, and climate. From the massive icebergs calving off of South Sawyer Glacier to the intricate textures and beauty of Baird Glacier, these icey giants offer a unique window into the Earth’s past. By fostering a deeper understanding and appreciation of Southeast Alaska’s glaciers, we not only celebrate their existing beauty but also help safeguard their legacy for future generations.

So, whether you’re drawn by their majestic landscapes or the scientific mysteries they hold, the glaciers of Southeast Alaska are best experienced close up, where their majestic beauty can be truly absorbed and appreciated.

Our goal with Alaska Sea Adventures aboard the MV Northern Song is to build lasting memories of a once-in-a-lifetime Alaskan yacht cruise and give you up-close and personal interactions with the vast beauty that Southeast Alaska has to offer.

And as you can see, each of these giants is a little different, so you have to explore them all! Explore our Alaskan Yacht Cruises

Written by First Mate Ryan Walker