This spring, two artists are developing an immersive sonic experience for the Brooklyn Botanic Garden that will turn visitors’ attention from the buzz of their cellphones and the hum of the city toward the land they inhabit. The sound installation, Terminal Moraine, was created by Brian House and Ben Rubin and will juxtapose the massive glacial event that formed the area with the growth of the trees that inhabit it in an effort to sonify the geological and natural history of Brooklyn.
The garden is a 52-acre oasis in the middle of New York City’s most populous county. “It’s kind of a poetic image,” said House of the installation’s setting in an interview with GlacierHub. “The fact that it is the botanic garden, and that there’s this cultivation of these species there, and this interplay between biological growth and ice which has modulated the biosphere of the region forever.”
The Brooklyn Botanic Garden has a deep connection to glaciers: the land it sits upon was forged by them during the most recent glaciation of North America, the Wisconsin Glaciation, which ended about 11,000 years ago. The garden and most of the northeastern United States were under thick ice. The movement of this glacier caused a pile up of debris as it pushed along, creating a massive ridge of debris at its edge known as a terminal moraine.
“If you look at where the terminal moraine ended up, it cuts right through Brooklyn,” Rubin told GlacierHub. “Brooklyn Botanical Garden is right smack in the middle of that zone. It’s on this raised ridge, almost, that runs all the way from Bay Ridge [in western Brooklyn] to Montauk [at the eastern tip of Long Island].”
To help people understand this glacial history, the artists will pipe sounds of ice into the walled garden. “In the timescale of someone who is spending 5-10 minutes in the installation, they might be aware of changes to the ambient background sound, but I want to be gradually bringing up the level and introducing various noises in order to suddenly remove them,” said Rubin, an artist, designer, and computer programmer. “The idea is thinking about a gradual change in the environment, like what we have been experiencing, and then the possibility that there is some sort of break in the global equilibrium that will have a sudden and dramatic impact on tree growth, for instance.”
The sounds of tree growth and glacier melt will be played simultaneously in the exhibition to create the contrast Rubin described. House, who studied computer music at Columbia University and has previously exhibited work at New York’s Museum of Modern Art and the Los Angeles Museum of Contemporary Art, elaborated on the impact of the intertwined sounds, saying “Glaciers exist on a very large timescale. It’s very difficult for people to perceive the dynamics of it. The idea is that a tree growing in Brooklyn is something that could witness the end of glaciers on a different time scale and the fact that it’s growing in glacial soil… It might have an awareness of what the process actually is, that a human walking through that space would largely be ignorant of.”
This is not the first time that Rubin has sought to make art from glacial data. In 2018, he created an installation with Jer Thorp that brought the sound of real-time glacial data into an installation in downtown Calgary, Alberta. “The idea was to give a voice to this glacier,” explained Rubin. “We are connected to the glacier both by the data that’s coming from it and from the river that flows through Calgary, the Bow River, which has its source at the Bow Glacier. We were trying to create a presence for the glacier that is situated in this downtown plaza.”
Rubin and House are using ambisonic audio to build their exhibit. This technology allows for sound to be sculpted in 360 degrees. Most of the recordings we hear today are recorded in stereo, where two microphones pick up sound and then the recording is laterally split between a left and right speaker. Ambisonic recordings use a tetrahedral microphone structure to record sound and then apply mathematics to combine four audio tracks to create a three-dimensional sound sculpture. This system allows listeners to have an experience that changes as they move around the space.
“It’s eight speakers around [the walled garden],” explained House. “With the ambisonics, it’s not that there’s one sound in each speaker, they will all contribute. We can place a sound anywhere in that space and it can commingle with the stuff that is there.”
The installation will be composed of recorded sounds in addition to sounds made using algorithms and samples. “We are working on a few layers of sound,” said Rubin. “Some background layers that will be drawn from recordings in the space, really blending the inherent sound of the space back in, but then adding to and modulating that in different ways. We are still trying to figure out what the ice is going to sound like exactly.”
“We have talked about using some instrumental samples from some musicians,” added House. “Whether that’s cello samples for the tree structure, or harp samples when it comes to the ice, as a more ephemeral sounding instrument.”
In using algorithms to create sound, House and Rubin see parallels to organic structures. “Looking into ice has been so interesting, because on a molecular level it has this hexagonal structure to it,” said House. “Thinking about these big phenomena from an algorithmic perspective, the molecular level of that has an interesting structure to it.”
The structure of the sounds representing ice will not only mimic its hexagonal structure, but also the deconstruction that occurs when ice melts and those crystalline structures break down. “We can move all the crystals in and out of synchronization as well as elongate and deform the envelopes,” explained House. “It is intended to be analogous to the deformation of crystals within glacier ice and the process of alignment happening under pressure. We can also disintegrate the crystals to melt the sheet, and move the sheet as a whole through the space as a function of the receding glacier.”
The algorithms that create the sounds of tree growth are based on L-systems, a series of algorithms modeled on the branching growth that occurs in the natural world. House and Rubin built their own system that “grows” trees based on these patterns. As the algorithm grows, each of the new branches has a unique sound in relation to the origin. “Each tree limb is a sound that is pitched according to its structural relationship in the tree,” said House. “If you follow a branch from the trunk to a leaf, it’s a type of harmonic series.”
Tree growth and glaciers are more closely linked than one might imagine. Not only do formerly glaciated areas give way to forested land, but trees are creating a record of our current climate conditions in real time. As trees grow, their rings radiate out in concentric circles. Each growth band provides a record of information about environmental conditions, and tree ring records are an important tool that climate scientists use to reconstruct climate data.
In Terminal Moraine, Rubin and House will play on the intrinsic relationship between trees and glaciers. They plan to create vignettes of sound, from three to five minutes long, that tell the story of the two timescales; the glaciers that sculpted this land and the trees that inhabit it. “You will hear a tree grow in those three to five minutes, or you will hear some ice melt and fall apart, stitched together by these sounds that link it to the place,” said House.
The artists hope that their work can help people connect with the environmental changes that we are witnessing on a global scale. “Glacier recession happens far away, out of sight and on a slower timescale than is perceptible or meaningful for people in a common sense way,” said Rubin. “What artists can do is find ways of bringing those shifts into some sort of graspable focus.”
You can experience Terminal Moraine in the walled garden at the Brooklyn Botanic Garden from April 9 to June 6, 2021. Advance tickets are required for entry and are available directly from the Brooklyn Botanic Garden.