The Conrad and Sonnblick Observatories

Taking the Earth’s Pulse

The seismic-gravimetric part of the Conrad Observatory.
PHOTO: ZAMG/LAMMERHUBER.

When entering the Conrad Observatory you suddenly feel like in the scenery of a James Bond movie: two kilometers of shafts and tunnels deep in a mountain 50 kilometers south-west of Vienna and flashing lights of bizarre instruments. These instruments measure worldwide earthquakes and explosions from nuclear tests as well as smallest changes in the earth’s gravity and magnetic field and are part of detection systems for solar storms to protect the Austrian electricity grid.

The Conrad Observatory of the Austria’s Central Institute for Meteorology and Geodynamics (ZAMG) is a geophysical observatory including several observation and research facilities and covering basically all fields of earth sciences. “The remoteness of the location is ideal for geophysical investigations. It is the only observatory of this type in the whole Alpine region,” says Roman Leonhardt, Head of the Observatory. “The site is characterized by an extremely low background noise, natural as well as technological, and guarantees constant temperature conditions for all measurement techniques and experiments. In addition, the design as an underground observatory reduces surface vibrations.

The Observatory has its own unbreakable power-supply and is connected via data-transmission lines with the Central Institute for Meteorology and Geodynamics in Vienna. Basically all processes and experiments can be controlled remotely.” The range of supported measuring methods, the instrumentation, and the observatories’ layout make it a unique research and development location for earth scientists of all disciplines. Among the earth processes continuously monitored at the Conrad Observatory are global earthquakes, earth tides, magnetic field variations, geodetic parameters, as well as atmospheric waves and meteorological data.

Accurate measurement and continuous monitoring of all those variations is essential to our understanding of cause and effect of these fundamental geophysical processes. The observatory is member of the most important international networks for each research field like IRIS (seismology) and INTERMAGNET (magnetism). The data quality is frequently rated as outstanding and used worldwide by well-known institutions like NOAA and ESA. Beside the observational instrumentation, several research and calibration facilities are installed at the Conrad Observatory.

This infrastructure includes calibration systems for seismometers and magnetic sensors, reference stations, as well as laboratories for material research and magnetism, and is used by many different national and international collaborators. An actual example is usage of the Merritt coil system, a magnetic calibration facility installed in cooperation with the Austrian Institute of Space Research (IWF). It enables a precise calibration of magnetic sensors in a magnetically very clean environment. Currently, an absolute scalar sensor developed by the IWF for ESA’s first large mission to Jupiter is investigated within this coil system. From 2022 onwards it will be part of JUICE, the first European satellite mission to the outer solar system to explore the magnetic field of Jupiter and its moons.

The Conrad Observatory is named after the Austrian-American geophysicist Victor Conrad. He is best known in earthquake research for suggesting a boundary layer in the earth’s crust, which later entered science as the “Conrad discontinuity.” Victor Conrad was appointed as the first head of the Austrian Seismological Service at the ZAMG in 1904 and worked many years for this institution. He ended his career at Harvard University in Cambridge, Massachusetts, where he worked as a teacher and researcher until the age of 80.

Science above the clouds: The Sonnblick Observatory

Sonnblick Observatory. Measurements in an almost interference-free atmosphere at 3,106 meters above sea level
PHOTO: ZAMG/SCHEER

A visionary scientist and an assertive businessman interested in nature laid the foundation for turning a - carefully put - very challenging idea into a scientific success story with worldwide significance. One was Julius Hann, from 1877 to 1897 director of the Central Institute for Meteorology and Geodynamics (ZAMG). He promoted the expansion of mountain weather stations for research in higher atmospheric layers. The other was Ignaz Rojacher, owner of a gold mine in Rauris, Salzburg. After climbing several peaks in his region, he came to the conclusion that he had found an ideal location for a meteorological measuring station: the free-standing summit of the Mt. Hoher Sonnblick, at 3,106 meters above sea level.

Construction of the observatory began in early summer of 1885. The material was brought to the summit with improvised cable cars made of wood and on foot. The opening of the Sonnblick Observatory took place on September 2, 1886. Today, the Sonnblick Observatory of Austria´s Central Institute for Meteorology and Geodynamics is an internationally sought-after research location. Its research and monitoring program is structured into three subprograms: the atmosphere, cryosphere and biosphere and focuses especially on climate and environmental studies.

The Observatory is located at the top of Mt. Hoher Sonnblick, about 120 km south of the city of Salzburg at an altitude of 3.106 meters, embedded in the core area of the nature reserve area Nationalpark Hohe Tauern. “The Sonnblick Observatory has one of the longest continuously measured temperature time series of the world in such altitudes with more than 130 years of data. Its unique location allow climate relevant CO2 measurements underlining the increasing trend within the last 20 years,” says Elke Ludewig, head of the Observatory and former scientist of the polar research station Neumayer III in the Antarctic.

The Sonnblick Observatory is accessible via a private cable car, which can also be used for profile measurements between the valley and the top. Due to the installed power supply and the private access, the station site is nearly emission free, an advantage for atmospheric background studies. A redundant telecommunication system allows remote access and near-real time data provision.

The Sonnblick Observatory operates 24/7 having at least two technicians on site. The Sonnblick team supports projects, helping with the sampling of probes, observations or the maintenance and operation of instruments while the scientist are not on site. Several universities and research institutions are using the site’s infrastructure and services for their projects. What started with a crazy idea more than 130 years ago is nowadays an important contribution to humanity.

Further Information: https://www.zamg.ac.at/cms/en/news