Measuring the Changing Soundscape in Glacier National Park
Pittsburgh, Pa., USA: From the eerie echo of a bugling elk to the gentle
swoosh of water lapping against a stony shore, a unique combination of
sounds helps distinguish each national park. This acoustic environment, as
perceived by humans, is known as a soundscape, and it is a vital
attribute—albeit one that is increasingly under threat from anthropogenic
noise.
Whether from the hum of an aircraft or human voices carried on a breeze,
the unwanted intrusion of sound has the potential to adversely impact
visitors and wildlife in natural areas. Now
new research
to be presented Tuesday at the annual meeting of The Geological Society of
America documents how the acoustic environment in Glacier National Park has
changed in the past 19 years—and what the implications are for protecting
this unique resource.
“The focus of my project in Glacier was to conduct sound monitoring to see
how the soundscape has changed, says Whitney Wyche, a
Mosaics in Science
intern who led the study. “Many visitors come to national parks to
experience natural peace and the sounds of nature. To preserve this natural
soundscape for future generations, it needs to be monitored and managed.”
A BASELINE FOR ASSESSING THE IMPACTS OF NOISE
A
growing body of research
indicates that noise affects both marine and terrestrial wildlife, causing
animals to alter vocal and foraging behaviors, reducing the abundance of
species in noisy habitats, and impacting the structure of ecological
communities. Noise can also affect how wildlife navigate the landscape,
from mating to locating prey to other communications crucial for wildlife
to survive.
“A predator that can hear sounds within a radius of 9 m 2 in a
natural soundscape would only be able to hear sounds within a radius of 7 m
2 if one decibel of sound was added to the natural soundscape,”
wrote Wyche in an
internship blog. “My project, which is a continuation of a soundscape project in Glacier
from 2004, can provide more information about the natural soundscape,”
added Wyche, who recently graduated from Franklin & Marshall College
with a bachelor’s degree in environmental science.
The 2004 research was conducted in Glacier by the Federal Aviation
Administration, the National Park Service, and the Volpe National
Transportation Systems Center. The project established a baseline for the
park’s natural soundscape from which potential noise impacts could be
assessed, including from aircraft operations over and near the park. At
that time, aircraft were a
growing concern—especially scenic helicopter rides that originated outside the park
boundary but that intruded on the natural soundscape across a wide area,
particularly affecting hikers and backpackers.
In 2019, students from Worcester Polytechnic Institute investigated the
soundscape at some of the same sites as the 2004 baseline study. They found
that aircraft noise remained about the same.
AIR TOUR MANAGEMENT PLAN
But the results of Wyche’s study are different. This is due in part to the
fact that the number of commercial air tours has decreased since 2004 as a
result of restrictions from the park’s new
Air Tour Management Plan, whereas the number of visitors has increased by about 50%. These changes
have had mixed impacts on the park’s acoustic environment, according to
Wyche and her co-authors, Jillian McKenna and Damon Joyce, who both work for
the park service.
Completing an air tour management plan is a long process, and having
acoustic data available before and after Glacier’s plan was completed is
noteworthy, according to Wyche. “It’s exciting to be the next step in the
research process by conducting acoustic monitoring after the plan was put
into place,” says Wyche.
To monitor Glacier’s changing acoustic environment, the intern set up
monitoring equipment, including a sound level meter, digital audio
recorder, and meteorological equipment, at sites around the park for two
weeks per site. Wyche then used software from the park service’s Acoustic
Monitoring Toolbox, including the Sound Pressure Level Annotation Tool, to
identify sound sources by analyzing spectrograms by highlighting sound
sources based on their visual signature.
“The percentage of time with audible propeller aircraft remained similar at
sites near the current air tour route, while decreasing at Logan Pass,
which is not near the currently authorized air tour route,” says Wyche.
Future steps include continuing the acoustic monitoring to extend the
record of the park’s changing soundscape, according to Wyche. This will be
especially important as the park
phases out commercial air tours
by the end of 2029. “Monitoring how Glacier National Park’s soundscape has
changed will help inform park management on what threats to the natural
soundscape need to be mitigated,” says Wyche.
Wyche worked in Glacier National Park during the summer of 2023 as part of
the
Mosaics in Science Diversity Internship Program, which provides college students and recent graduates who are
underrepresented in STEM (science, technology, engineering, and math)
career fields with on-the-ground, natural resource science-based work
experience in the National Park System. The program is operated in
partnership with
Environment for the Americas
.
“I greatly enjoyed my experience working as a Mosaics in Science intern,”
says Wyche. “I especially appreciated the goal of the internship program
because it makes environmental careers more accessible to people of color.”
Measuring Soundscape Change at Glacier National Park
Contacts: Whitney Wyche, Mosaics in Science Intern, whitneywyche2@gmail.com; Gina Icenoggle, National Park Service, gina_icenoggle@nps.gov
193: T39. Geoscience and Hydrology of Your Public Lands: STEM
Internships, Research, Science, Mapping, Resource Management, and
Education
Tues., 17 Oct., 2:35–2:50 p.m.
The Geological Society of America (
https://www.geosociety.org
) unites a diverse community of geoscientists in a common purpose to
study the mysteries of our planet (and beyond) and share scientific
findings. Members and friends around the world, from academia,
government, and industry, participate in GSA meetings, publications,
and programs at all career levels, to foster professional excellence.
GSA values and supports inclusion through cooperative research, public
dialogue on earth issues, science education, and the application of
geoscience in the service of humankind.
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