7th NOVAC Workshop

The 7th NOVAC workshop will take place from 5 to 12 May 2024 at El Reventador volcano, Ecuador. The objective of this workshop is to facilitate the exchange of knowledge and experience among staff from partner institutions. The workshop is aimed at gas geochemists and field engineers working on NOVAC instrumentation, data analysis, and interpretation. An introduction will be given to NOVAC instrumentation, software, and analysis tools, and new technology and software features will be demonstrated. Partners will share insights on volcanic systems obtained from their own gas measurements, and novel analysis of NOVAC data will be discussed. Finally, plans for the coordination of the network and future NOVAC activities will be made. For additional information on the cost, logistics, and schedule of the workshop, as well as instructions on how to register, please see the 2nd Circular. Registration deadline is Feb 29, 2024.

This workshop is possible thanks to financial support from the Volcano Disaster Assistance Program (VDAP) of USGS/USAID, the International Geoscience Programme of UNESCO/IUGS, and the European Geosciences Union (EGU).

El Reventador volcano. Photo by J. Salgado (IG-EPN)

DOAS networks upgraded at San Miguel and Santa Ana volcanoes, El Salvador

San Miguel and Santa Ana volcanoes (El Salvador) are both very active, high-threat volcanic systems. San Miguel is El Salvador’s most active volcano and has experienced multiple eruptions in recent years, including in 2022 and 2023. Santa Ana hosts a highly acidic lava lake and fumaroles and has a geologic record of diverse eruption styles. Santa Ana is also a popular tourist destination, which amplifies the importance of tracking any changes in its volcanic activity. El Salvador’s Ministerio de Medio Ambiente y Recursos (MARN) was one of the first members of NOVAC and has installed multiple generations of NOVAC instruments across the country over the last ~15 years. With assistance from the USGS-USAID Volcano Disaster Assistance Program (VDAP), MARN gas geochemists and field engineers recently upgraded NOVAC Scanning DOAS instruments at both San Miguel and Santa Ana volcanoes. San Miguel is now monitored with two DOAS instruments and Santa Ana has a single, well-positioned instrument downwind. Additionally, MARN has a new MobileDOAS system for vehicle-based campaign measurements of SO2 at their volcanoes. Collectively, these updated NOVAC instruments will enable MARN to monitor gas emissions and how they relate to changing volcanic activity at their two most active volcanoes.

NOVAC instruments installed on Merapi Volcano, Indonesia

Merapi Volcano (Java, Indonesia) is a high-threat volcano with a history of eruptions that have had significant impact on tens of thousands of people living in the larger Yogyakarta metropolitan area. Merapi has been particularly active, erupting lava and producing pyroclastic flows, and the volcano’s alert level has been kept at the second highest mark (“Siaga”) since 2020. Supported by the USGS-USAID Volcano Disaster Assistance Program, gas geochemists and field engineers with the Indonesian Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) have now installed a network of Scanning DOAS instruments on the volcano. Located at forward observation posts to the north, west, and south of the Merapi’s summit, the instruments allow SO2 emission rates to be tracked continuously and compared with other indicators of volcanic activity. The BPPTKG produced a short video describing the project, which can be viewed at https://www.youtube.com/watch?v=c8FmAJ-zCPk&t=1s

NOVAC stations installed on Rincón de la Vieja

Located in NW Costa Rica, Rincón de la Vieja produced a significant eruption on June 28, 2021, which triggered lahars/mudslides that threatened communities and infrastructure to the north of the volcano. This was likely the most significant eruption from Rincón de la Vieja in the last two decades and could indicate a new phase of enhanced activity. During May 9-11, 2022, a team of field engineers and gas geochemists from the Observatorio Vulcanológico y Sismológico de Costa Rica (OVSICORI) and the USGS Volcano Disaster Assistance Program (VDAP) successfully installed two Scanning DOAS on the east side of the volcano, approximately 6 km from the summit crater. The data from these instruments will help OVSICORI assess ongoing activity at the volcano and inform risk assessments.

OVSICORI gas geochemist Maarten de Moor applies sealant to a new NOVAC station installed on Rincón de la Vieja volcano.

New video tutorial shows how to troubleshoot the scanner end switch

One common failure mode for the NOVAC scanners is a loose or incorrectly positioned scanner end switch. When working properly, the end switch defines the reference position of the scanner and tells the instrument which way is up. Problems with the end switch can cause the scanner to rotate indefinitely without the measurement ever starting, or make the instrument scan the ground rather than the sky. A new video in the Tutorials library shows how to troubleshoot this issue.

Welcome Carlos Laverde as new Software Working Group Coordinator

We are excited to announce that Carlos Laverde (Servicio Geológico Colombiano) has agreed to step into the role of the NOVAC Software Working Group Coordinator. Thank you Carlos! In recent years, Carlos has been one of the most active members in our community, particularly in the testing and development of software. Working closely with Diana Norgaard, he provided valuable feedback on the NOVAC Program and Mobile DOAS applications. His recent work also includes developing a platform for visualizing  spatial SO2 data from the TROPOMI satellite instrument. Working at SGC, his experience with operational volcano monitoring provides him with valuable insights into the priorities and challenges of operating continuous monitoring networks such as NOVAC. We look forward to working with him on all software-related tasks!

New resources for obtaining model wind information

Two new resources for estimating wind speed and direction have recently been made available to the NOVAC community. Wind information is essential for converting measured sulfur dioxide burdens to volcanic emission rates.

For real-time emission rate estimates, wind forecast data from the NOAA Global Forecast System (GFS) are uploaded to the ‘Wind’ directory on the NOVAC sftp server. Files in this directory contain forecast conditions for the next 7 days. These data can be loaded automatically by the NOVAC Program such that the calculation of real-time sulfur dioxide emission rates is based on these wind forecasts.

In addition, historical (2005-2021) wind information from the ECMWF ERA5 model are now available in the ‘ecmwf’ directory on the NOVAC sftp server. These data provide a higher temporal and spatial resolution than data from the GFS, and are thus ideal for re-analyses of sulfur dioxide emission rates.

For more information on the use of these resources, please contact the NOVAC software working group.

NOVAC Program v3.2 & v3.3 Releases

In February, version 3.2 of the NOVAC Program software was released and members of the NOVAC community was informed through email on its availability. Version 3.3 is also now available. There are couple of key changes that users should be aware of when transitioning to versions 3.2 or 3.3 from 3.1 and below:

  • Data uploads to Chalmers servers are transitioning to use the SFTP protocol. This requires a separate account for each observatory. Observatories that are uploading data should have been contacted with their account information.
  • The latest versions of NOVAC Program require additional DLLs that support SFTP (libcrypto-1_1, libcurl, and libssl). They are in the zip file of the distribution package and need to be in the same folder as the executable for the software to work.

Download Version 3.3

Download Version 3.2

When upgrading software, always back up your configuration.xml and the executable in case you need to revert to the previous version.

Version 3.2 Change Notes

Bug fixes

  • Fix issue with columns from same scan initially plotting at same time in history (#99)
  • Fix issue with software crashing on re-evaluation when solar spectrum file is used (#103)
  • Fix peak intensity/specsaturation (#108)
  • Fix issue with SO2 blue reference line being flat during re-evaluation

New features

  • Support for user-configurable spectrometer (#6)
  • SFTP support for uploading pak files to offsite server (#58)
  • Hostname support for FTP to instrument computer (#81)
  • Addition of flux history tab (#107)
  • AveSpec spectrometer support
  • Axiomtec instrument computer support
  • Add new “IntegrationMethod” property to STD file (#126)
  • Streamlined logging for FTP upload

Version 3.3 Change Notes

Bug fixes

  • Fix quirks when deleting scanners (#140)
  • Fix evaluation progress bar not working in Re-Evaluation dialog (#132)
  • Return parsing error if no ws, wd, or ph read from wind file in post flux dialog (#147)

New features

  • Directory polling option (#111)
  • Merge Evaluation Log feature (#136)
  • Upload evaluation logs to FTP/SFTP server (#137)
  • Use passive FTP when connecting to instrument PC

Mount St. Helens joins NOVAC

On June 16, 2021, the U.S. Geological Survey established a new monitoring site on the east side of the iconic Mount St. Helens volcano in Washington, USA. The volcano is currently quiet with no sulfur dioxide being emitted, but the scanner will provide situational awareness if and when the volcano becomes restless in the future.

NOVAC database released for 2005-2016

We are pleased to present a detailed database of SO2 emission rates, plume locations, and meteorological conditions, derived from measurements conducted during the period 2005-2016 at 32 volcanoes in NOVAC. The database is hosted at https://novac.chalmers.se/.

Data presented in this database indicates the magnitude and natural variability of degassing observed at a daily temporal scale.

These data are freely accessible but we expect that proper credit is given to volcano observatories in case of scientific use, as indicated in our Data Use Agreement https://novac.chalmers.se/datauseagreement.

An article describing and analyzing these data was published by the collaboration: Arellano et al. (2021), https://essd.copernicus.org/articles/13/1167/2021/essd-13-1167-2021.html