Eos, Vol. 92, No. 26, 28 June 2011
surprising that he won the outstanding
teacher award in the UCLA physics department four times, which for him was a
source of great pride.
He began his career with a series of
laboratory experiments that compared
seismic theory with observations. His laboratory skills led to his codiscovery with
George Kennedy of thermoluminescence
dating. In 1956 his work took a theoretical
turn, resulting in a famous paper that led
to the representation theorem for calculating ground motions arising from body
forces and motions on a surface such
as an earthquake fault. In that paper,
Knopoff extended to the elastodynamic
problem Kirchhoff’s retarded potential
solution to the wave equation, thereby
providing the elastic analog to Green’s
theorem.
Knopoff often used his sense of humor
to emphasize a point. A famous paper with
the shortest title possible, “Q,” is a paper
that describes in detail the attenuation
of elastic waves in the laboratory and in
Earth and then presents a thorough theoretical analysis of several mechanisms
that might explain such attenuation. Published in 1964 in Reviews of Geophysics,
“Q” continues to be widely quoted. In contrast, with John Gardner he published a
paper with the remarkably long title “Is
the sequence of earthquakes in Southern California, with aftershocks removed,
Poissonian?” followed by the shortest
abstract: “Yes.” In 1974 he copyrighted his
version of Mahler’s Das Lied von der Erde
in two (Earth) movements, composed of
computer-­generated music. The first movement was based on seismicity from the
1952 Kern County, California, earthquake,
and the second was an accelerated digital recording of the normal modes of the
Earth.
As his career developed, Knopoff moved
from the laboratory to the field. He pioneered the installation of temporary longperiod seismograph arrays with an experiment in the European Alps reported in
1966. With colleagues he developed an
­ultralong-​­p eriod seismometer installed at
the South Pole that made the first measurements of solid Earth polar tides and
vibrational modes of the Earth unaffected
by splitting due to rotation and ellipticity.
His group used surface waves to define the
main structures of plate tectonics, including the thickening of the lithosphere with
age of oceanic plates and the very deep
roots, or keels, under continental shields.
In seismic theory he has many canonical analytical expressions to his name.
Of note is his (1958) elegant solution to
the antiplane crack, which ranks in fame
alongside the inplane (1928) Starr crack
and the Eshelby (1949) circular crack. He
developed efficient algorithms to solve
the problem of elastic waves propagating in layered media and to compute seismograms by superpositions of normal
MEETING
Estimating Uncertainties in Watershed Studies
Quantifying Uncertainty in Ecosystem Studies (QUEST) Workshop:
Uncertainty in Hydrologic Fluxes of Elements at the Small Watershed Scale;
Boston, Massachusetts, 14–15 March 2011
PAGE 220
Small watersheds have been used
widely to quantify chemical fluxes and
cycling in terrestrial ecosystems for about
the past half century. The small watershed
approach has been valuable in characterizing hydrologic and nutrient budgets,
for instance, in estimating the net gain or
loss of solutes in response to disturbance.
However, the uncertainty in these ecosystem budget calculations is generally
ignored. Without uncertainty estimates in
watershed studies, it is difficult to evaluate
the significance of observed differences
between watersheds or changes in budgets over time, and erroneous conclusions
may be drawn. The historical lack of attention given to uncertainty has been due at
least in part to the lack of appropriate analytical tools and approaches. The issue
of uncertainty has been confronted more
rigorously in other disciplines, yet the
advances made have not been comprehensively applied to biogeochemical ­input-​
­output budgets. In recent years, there has
been growing recognition that estimates
of uncertainty are essential for coming
to sound scientific conclusions, identifying which budget components most need
improvement, and developing more efficient monitoring strategies, thereby maximizing information gained per unit cost.
A working group called Quantifying
Uncertainty in Ecosystem Studies (QUEST)
was recently established to better address
the issue of uncertainty in biogeochemical studies. The inaugural QUEST meeting
was funded by the Long Term Ecological
Research Network Office with support from
the U.S. National Science Foundation. Fifteen specialists working at the small watershed scale, including experts on uncertainty
analysis, hydrology, and ecology, met to
modes. He was one of the first to recognize the applicability to the earthquake
problem of modern developments in nonlinear science. The Burridge and Knopoff
model (1967) of interacting springs and
blocks became the basis for simulating
earthquake dynamics. With Yan Kagan
he developed the stochastic branching
model of faulting that displays the clustering properties of earthquake catalogs
including foreshocks, aftershocks, and
weak clustering of main shocks, providing a theoretical basis for earthquake
forecasting.
An accomplished pianist and harpsichordist, rather than choosing a professional career as a concert musician, he
chose a path that explored and appreciated the richness of physics, mathematics, and the Earth as well as of music. His
encyclopedic knowledge rendered a conversation with him an illumination, albeit
sometimes a challenge to keep pace. He
is missed both as a warmhearted person
and an intellect, and he leaves a legacy of
teaching and research at the highest levels
that serves as a prime example of unselfish cooperation.
He is survived by his wife, Joanne; children Katie, Rachel, and Michael; and a
grandson.
—Paul Davis and David Jackson, UCLA; ­E-mail:
­pdavis@​ucla​.edu; and Freeman Gilbert, University
of California, San Diego
develop a strategy for conducting a synthesis of uncertainty in ­input-­output budgets
of major elements across small watersheds
with diverse characteristics.
The meeting began with a series of short
site presentations, followed by a discussion
of uncertainty in streamwater flux, precipitation flux, and potential workshop products. The following sources of uncertainty
were identified: measurement error (e.g.,
laboratory analysis of solute concentrations), sampling error (especially temporal
variation in the case of stream chemistry
and spatial variation in the case of precipitation amounts), regression or conversion
error (e.g., ­stage- ​­discharge relationship),
and model selection error (e.g., multiplying a weekly concentration by a weekly discharge versus including additional predictor variables to describe changes in chemistry during the week). The group recognized
that among the selected watersheds, some
sources of uncertainty are particularly challenging to quantify, such as blowing snow,
groundwater, and melting glaciers. Key decisions were made about the synthesis, including the sources of uncertainty that would be
evaluated, ions to include in the analysis,
and the time frame that would be used.
This initiative will help increase awareness of different methods for including
uncertainty in ecosystem budgets and provide the biogeochemical research community with the theoretical and analytical tools
Eos, Vol. 92, No. 26, 28 June 2011
to analyze uncertainty in many types of measurements. These efforts will help QUEST
achieve its primary goal, which is to facilitate
a cultural change in which uncertainty analysis becomes an accepted and expected practice in biogeochemical studies.
Further information about this organization can be found on the QUEST Web site
(http://​w ww​.­quantifyinguncertainty​.org).
Those interested in participating in QUEST
should ­e -mail ­quantifyinguncertainty@​gmail​
.com.
ral Resources Management, State University of New
York College of Environmental Science and Forestry,
Syracuse; Mark Green, Center for the Environment,
Plymouth State University, Plymouth, N. H.
—John Campbell, Forest Service, U.S. Department
of Agriculture, Durham, N. H.; ­E-mail: j­lcampbell@​fs​
.fed​.us; Ruth Yanai, Department of Forest and Natu-
ABOUT AGU
2011 Mass Media Fellow
Lands at Voice of America
PAGE 220
Although on track to earn her Ph.D.
in atmospheric physics next year, Dione
Lee Rossiter is looking forward to a different sort of science career than the oftensought-after academic or research position. Her calling, she says, is science outreach, advocacy, and communication. Her
eyes flash and her smile widens when she
talks about illuminating science, making it
feel relevant, credible, and important and
rendering it understandable to the many
people who often find science just the
opposite.
“If people just understood science on a
little bit higher level, they could start making more informed decisions. That’s one
of my ­p assions—​­seeing that people are as
excited as I am,” she says.
AGU is supporting Rossiter as the
Union’s 2011 Mass Media Science and
Engineering Fellow. Selected as one of
11 young scientists to work for 10 weeks
this summer as a science journalist, Rossiter expects the Fellowship to help her
build communication skills and media
savvy that she will need for the career she
envisions. Each year since 1997 AGU has
supported a Fellow through a program
administered by the American Association
for the Advancement of Science.
Rossiter is working at Voice of America
(VOA) in Washington, D. C., where she
started her stint as a reporter on 13 June.
Becoming part of a busy newsroom, with
television screens everywhere tuned to
different news channels, is exhilarating,
she says, and very different from anything
she has experienced before. “It’s very surreal, but very exciting.”
It is also daunting, she admits. Fortunately, she says, her new colleagues on
VOA’s science desk—all of them reporters,
none of them scientists—have gone out of
their way to help her. They have also been
coming to her to ask science questions
on topics ranging from plate tectonics to
cloud physics, her scientific specialty. “I’m
loving that. At least I feel helpful that way,”
she says.
In her usual life as a graduate student,
Rossiter can be found at the University
of California, Santa Cruz, where she studies marine stratocumulus clouds. Those
are the ­low-​­hanging behemoths that drift
above roughly a third of the world’s ocean
surface at any given time. Her studies
focus on the microscopic behavior of tiny
water ­droplets— ​­drizzle—​­beneath those
clouds.
It is the kind of scientific work that could
have big implications for society. “If we
can nail down how clouds work, then we
can better understand how the climate is
changing,” she explains. She anticipates
completing the requirements for her doctorate in spring 2012.
Rossiter has previously explored other
ways of reaching out to the public with her
science knowledge and enthusiasm. For
2 years, she taught science to youngsters
ranging from preschoolers to high school
juniors at the Lawrence Hall of Science in
Dione Lee Rossiter
Berkeley, Calif. While there, she was interviewed as part of a live MSNBC program
about earthquakes. During an atmospheric
science field campaign in Chile, Rossiter
contributed “postcards from the field”—
brief, chatty, scientific field reports aimed
at c
­ hildren—​­to the science education Web
site Windows to the Universe.
Each of those experiences has given
her a taste of a different way of connecting about science with people who are not
fellow scientists, as well as skills for making those connections meaningful. The
Fellowship, she hopes, will teach her how
to use words as powerfully as she already
uses her personality to excite people
about science.
“Personality is how I really hook people,” Rossiter explains. But writing compelling news articles or radio scripts? “I have
no idea just yet how to do that in the most
effective way.”
—Peter Weiss, Public Information Manager, AGU;
­E-mail: ­pweiss@​agu​.org