Confluences is a multi-disciplinary art installation that combines sonic and visual elements to investigate how climate change will impact extreme high sea level events in San Diego, California. The piece was commissioned by the La Jolla Historical Society and informed by research from scientists at the Scripps Institute of Oceanography. It is part of the exhibition Weather on Steroids: The Art of Climate Change Science, curated by Tatiana Sizonenko with Science Consultant Alexander Gershunov.

High tides, winter storms, and long-term El Niño-Southern Oscillation cycles, can converge to produce high, destructive seas along the coast of California. The effects of these convergences will be exacerbated by climate change-induced sea level rise. Leonard’s installation gives voice to these causal factors and concerning predictions that the number and intensity of extreme high sea level events will increase as the 21st century progresses. Confluences also references local impacts of extreme high sea levels such as erosion of shorelines, loss of sandy beaches and wetlands, and flooding of neighborhoods.

The installation is comprised of a background sound composition and a set of sculptural musical instruments that gallery visitors are encouraged to interact with. The background composition is comprised of audio field recordings of San Diego-area beaches, intertidal zones, and wetlands that will be underwater in the future, plus sounds from stones and kelp flutes. This 12-minute composition plays on a continuous loop. Confluences’ sculptural musical instruments abstractly embody tidal patterns, phases of the El Niño-Southern Oscillation, winter storms, and gradual sea level rise, through the use of sand, pendulums, and resonant glass surfaces. Three round glass tabletops are mounted on stands crafted out of driftwood and embellished with dried kelp. The tabletops are positioned in a semi-circle above a low wood platform and tilt towards its center. The wood platform is a half-circle and tilts slightly towards the viewer. Attached to the bottom surface of each glass tabletop is a contact microphone. A small funnel-shaped vessel, festooned with curved pieces of dried kelp, is suspended above each glass tabletop, forming three pendulums.

Gallery visitors are invited to add to the background soundscape by pouring sand into the hanging vessels and then setting the pendulums into motion. As sand falls onto the amplified glass surfaces, motions and patterns are given voice. Sand hits the glass tables initially and then slides down onto the wood platform. Over time sand builds up on the platform and spills over onto the gallery floor.

The size of each glass tabletop roughly correlates to the time scale (interannual, seasonal, monthly, daily) of the process it represents. The large glass corresponds to the El Niño-Southern Oscillation, the medium-sized one to winter storms, and the smallest to tides. The pitch of each glass surface reflects the amount of sea level rise contributed by its process, with higher pitches indicating greater increases. The volume capacity of each pendulum vessel relates to the duration of each process (years, months, days, hours). Variations in pendulum lengths and the addition of weights cause each vessel to swing in a unique pattern. Gradual sea level rise is alluded to by both the background composition and long-term build up of sand on the wooden platform and gallery floor.

Confluences has been exhibited at the La Jolla Historical Society Wisteria Gallery (February 11 - May 21, 2017), and the San Diego Central Library Gallery (June 10 – September 3, 2017).

Special thanks to the following scientists from Scripps Institute of Oceanography: Art Miller, David Pierce, Alexander Gershunov, Shang-Ping Xie, Kristin Guirguis, and Sarah Giddings; and to William Leonard, who served as engineering, adhesives, and physics consultant for this project.