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A Versatile Time-Lapse Camera System Developed by the Hawaiian Volcano Observatory for Use at Kilauea Volcano, Hawaii

Volcanoes can be difficult to study up close. Because it may be days, weeks, or even years between important events, direct observation is often impractical. In addition, volcanoes are often inaccessible due to their remote location and (or) harsh environmental conditions. An eruption adds another level of complexity to what already may be a difficult and dangerous situation. For these reasons, scientists at the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory (HVO) have, for years, built camera systems to act as surrogate eyes. With the recent advances in digital-camera technology, these eyes are rapidly improving. One type of photographic monitoring involves the use of near-real-time network-enabled cameras installed at permanent sites (Hoblitt and others, in press). Time-lapse camera-systems, on the other hand, provide an inexpensive, easily transportable monitoring option that offers more versatility in site location. While time-lapse systems lack near-real-time capability, they provide higher image resolution and can be rapidly deployed in areas where the use of sophisticated telemetry required by the networked cameras systems is not practical. This report describes the latest generation (as of 2008) time-lapse camera system used by HVO for photograph acquisition in remote and hazardous sites on Kilauea Volcano.

Scientific Investigations Report

The story of the Hawaiian Volcano Observatory -- A remarkable first 100 years of tracking eruptions and earthquakes

The year 2012 marks the centennial of the Hawaiian Volcano Observatory (HVO). With the support and cooperation of visionaries, financiers, scientists, and other individuals and organizations, HVO has successfully achieved 100 years of continuous monitoring of Hawaiian volcanoes. As we celebrate this milestone anniversary, we express our sincere mahalo—thanks—to the people who have contributed to and participated in HVO’s mission during this past century. First and foremost, we owe a debt of gratitude to the late Thomas A. Jaggar, Jr., the geologist whose vision and efforts led to the founding of HVO. We also acknowledge the pioneering contributions of the late Frank A. Perret, who began the continuous monitoring of Kīlauea in 1911, setting the stage for Jaggar, who took over the work in 1912. Initial support for HVO was provided by the Massachusetts Institute of Technology (MIT) and the Carnegie Geophysical Laboratory, which financed the initial cache of volcano monitoring instruments and Perret’s work in 1911. The Hawaiian Volcano Research Association, a group of Honolulu businessmen organized by Lorrin A. Thurston, also provided essential funding for HVO’s daily operations starting in mid-1912 and continuing for several decades. Since HVO’s beginning, the University of Hawaiʻi (UH), called the College of Hawaii until 1920, has been an advocate of HVO’s scientific studies. We have benefited from collaborations with UH scientists at both the Hilo and Mänoa campuses and look forward to future cooperative efforts to better understand how Hawaiian volcanoes work. The U.S. Geological Survey (USGS) has operated HVO continuously since 1947. Before then, HVO was under the administration of various Federal agencies—the U.S. Weather Bureau, at the time part of the Department of Agriculture, from 1919 to 1924; the USGS, which first managed HVO from 1924 to 1935; and the National Park Service from 1935 to 1947. For 76 of its first 100 years, HVO has been part of the USGS, the Nation’s premier Earth science agency. It currently operates under the direction of the USGS Volcano Science Center, which now supports five volcano observatories covering six U.S. areas—Hawaiʻi (HVO), Alaska and the Northern Mariana Islands (Alaska Volcano Observatory), Washington and Oregon (Cascades Volcano Observatory), California (California Volcano Observatory), and the Yellowstone region (Yellowstone Volcano Observatory). Although the National Park Service (NPS) managed HVO for only 12 years, HVO has enjoyed a close working relationship with Hawaiʻi Volcanoes National Park (named Hawaii National Park until 1961) since the park’s founding in 1916. Today, as in past years, the USGS and NPS work together to ensure the safety and education of park visitors. We are grateful to all park employees, particularly Superintendent Cindy Orlando and Chief Ranger Talmadge Magno and their predecessors, for their continuing support of HVO’s mission. HVO also works closely with the Hawaiʻi County Civil Defense. During volcanic and earthquake crises, we have appreciated the support of civil defense staff, especially that of Harry Kim and Quince Mento, who administered the agency during highly stressful episodes of Kīlauea's ongoing eruption. Our work in remote areas on Hawaiʻi’s active volcanoes is possible only with the able assistance of Hawaiʻi County and private pilots who have safely flown HVO staff to eruption sites through the decades. A special mahalo goes to David Okita, who has been HVO’s principal helicopter pilot for more than two decades. Many commercial and Civil Air Patrol pilots have also assisted HVO by reporting their observations during various eruptive events. Hawaiʻi’s news media—print, television, radio, and online sources—do an excellent job of distributing volcano and earthquake information to the public. Their assistance is invaluable to HVO, especially during times of crisis. HVO’s efforts to provide timely and accurate scientific information about Hawaiian volcanoes and earthquakes succeed only because of you, our receptive and keenly aware public. By following the activity of Hawaiʻi’s active volcanoes through our daily eruption updates posted on the HVO website, viewing HVO webcam images, reading our weekly “Volcano Watch” articles, and attending our public lectures, you help us to ensure that you can live safely with Hawaiʻi’s dynamic volcanoes. To everyone who has shared in HVO’s reaching this milestone—100 years of continuous volcano monitoring—we extend our deepest gratitude. Mahalo nui loa!

Hawai'i

Hawaiian Volcano Observatory Seismic Data, January to December 2006

Introduction The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M>1.5 routinely gathered by the Observatory are included. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. Beginning with 2004, summaries are simply identified by the year, rather than Summary number. The present summary includes background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered. A report by Klein and Koyanagi (1980) tabulates instrumentation, calibration, and recording history of each seismic station in the network. It is designed as a reference for users of seismograms and phase data and includes and augments the information in the station table in this summary.

Open-File Report

Hawaiian Volcano Observatory seismic data, January to December 2005

The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M-1.5 routinely gathered by the Observatory are included. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. Beginning with 2004, summaries will simply be identified by the year, rather than Summary number. The present summary includes background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered. A report by Klein and Koyanagi (1980) tabulates instrumentation, calibration, and recording history of each seismic station in the network. It is designed as a reference for users of seismograms and phase data and includes and augments the information in the station table in this summary.

Open-File Report

The Volcano Hazards Program — Strategic science plan for 2022–2026

The U.S. Geological Survey (USGS) Volcano Hazards Program (VHP) Strategic Science Plan, developed through discussion with scientists-in-charge of the USGS volcano observatories and the director of the USGS Volcano Science Center, specifies six major strategic goals to be pursued over the next 5 years. The purpose of these goals is to help fulfill the USGS VHP mission to enhance public safety and to minimize social and economic disruption caused by volcanic eruptions in the United States and its territories, through delivery of effective forecasts, warnings, and information on volcano hazards based on scientific understanding of volcanic processes. These six major strategic goals are to (1) continue—and when possible, accelerate—implementation of the National Volcano Early Warning System (NVEWS); (2) improve community preparedness for volcanic hazards by updating and standardizing essential components of volcano hazard assessments and providing training to land managers, emergency responders, and State and local communities; (3) develop the next generation of volcano hazard assessments using geographic information systems and other digital tools; (4) make observations with new instrumentation and take advantage of advances in real-time gas sensors; (5) rebuild the Hawaiian Volcano Observatory and its monitoring capabilities; and (6) form new partnerships and strengthen existing partnerships with other government agencies and with academia and industry, to advance volcano monitoring, increase understanding of volcanic processes, and disseminate USGS information. In its effort to advance volcano science and monitoring techniques, the VHP has identified six scientific targets to pursue over the next 5 years, including: (1) increased understanding of volcano seismicity; (2) improved probabilistic forecasting; (3) deepened grasp of volcano eruption histories and geochronology; (4) newly developed and refined physical models of magmatic systems, leading to better situational awareness and accuracy of eruption forecasts; (5) improved warnings and forecasts of volcanic ash and gas clouds and characterization of volcanic smog sources; and (6) refined lava-flow modeling and forecasting of lava-flow paths.

Circular

MATLAB tools for improved characterization and quantification of volcanic incandescence in Webcam imagery: Applications at Kilauea Volcano, Hawai'i

Webcams are now standard tools for volcano monitoring and are used at observatories in Alaska, the Cascades, Kamchatka, Hawai‘i, Italy, and Japan, among other locations. Webcam images allow invaluable documentation of activity and provide a powerful comparative tool for interpreting other monitoring datastreams, such as seismicity and deformation. Automated image processing can improve the time efficiency and rigor of Webcam image interpretation, and potentially extract more information on eruptive activity. For instance, Lovick and others (2008) provided a suite of processing tools that performed such tasks as noise reduction, eliminating uninteresting images from an image collection, and detecting incandescence, with an application to dome activity at Mount St. Helens during 2007. In this paper, we present two very simple automated approaches for improved characterization and quantification of volcanic incandescence in Webcam images at Kīlauea Volcano, Hawai‘i. The techniques are implemented in MATLAB (version 2009b, ® The Mathworks, Inc.) to take advantage of the ease of matrix operations. Incandescence is a useful indictor of the location and extent of active lava flows and also a potentially powerful proxy for activity levels at open vents. We apply our techniques to a period covering both summit and east rift zone activity at Kīlauea during 2008–2009 and compare the results to complementary datasets (seismicity, tilt) to demonstrate their integrative potential. A great strength of this study is the demonstrated success of these tools in an operational setting at the Hawaiian Volcano Observatory (HVO) over the course of more than a year. Although applied only to Webcam images here, the techniques could be applied to any type of sequential images, such as time-lapse photography. We expect that these tools are applicable to many other volcano monitoring scenarios, and the two MATLAB scripts, as they are implemented at HVO, are included in the appendixes. These scripts would require minor to moderate modifications for use elsewhere, primarily to customize directory navigation. If the user has some familiarity with MATLAB, or programming in general, these modifications should be easy. Although we originally anticipated needing the Image Processing Toolbox, the scripts in the appendixes do not require it. Thus, only the base installation of MATLAB is needed. Because fairly basic MATLAB functions are used, we expect that the script can be run successfully by versions earlier than 2009b.

Hawaii

Hawaiian Volcano Observatory seismic data, January to December 2004

The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M≥1.5 routinely gathered by the Observatory are included. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. Beginning with 2004, summaries will simply be identified by the year, rather than Summary number. The present summary includes background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered.

Hawaii

Hawaiian Volcano Observatory summary 100; Part 1, seismic data, January to December 2000

The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year and a chronological narrative describing the volcanic events. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that all data for events of M≥1.5 routinely gathered by the Observatory are included. The emphasis in collection of tilt and deformation data has shifted from quarterly measurements at a few water-tube tilt stations (“wet” tilt) to a larger number of continuously recording borehole tiltmeters, repeated measurements at numerous spirit-level tilt stations (“dry” tilt), and surveying of level and trilateration networks. Because of the large quantity of deformation data now gathered and differing schedules of data reduction, the seismic and deformation summaries are published separately. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. The present summary includes enough background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered.

Hawai'i

Hawaiian Volcano Observatory summary 101: Part 1, seismic data, January to December 2001

The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year and a chronological narrative describing the volcanic events. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that all data for events of M>1.5 routinely gathered by the Observatory are included. The emphasis in collection of tilt and deformation data has shifted from quarterly measurements at a few water-tube tilt stations ("wet" tilt) to a larger number of continuously recording borehole tiltmeters, repeated measurements at numerous spirit-level tilt stations ("dry" tilt), and surveying of level and trilateration networks. Because of the large quantity of deformation data now gathered and differing schedules of data reduction, the seismic and deformation summaries are published separately. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. The present summary includes enough background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered.

Hawai'i

Hawaiian volcano observatory summary 103; Part I, seismic data, January to December 2003

The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year and a chronological narrative describing the volcanic events. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M= 1.5 routinely gathered by the Observatory are included. The emphasis in collection of tilt and deformation data has shifted from quarterly measurements at a few water-tube tilt stations ('wet' tilt) to a larger number of continuously recording borehole tiltmeters, repeated measurements at numerous spirit-level tilt stations ('dry' tilt), and surveying of level and trilateration networks. Because of the large quantity of deformation data now gathered and differing schedules of data reduction, the seismic and deformation summaries are published separately. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. The present summary includes background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered.

Open-File Report

A century of studying effusive eruptions in Hawaii

The Hawaiian Volcano Observatory (HVO) was established as a natural laboratory to study volcanic processes. Since the most frequent form of volcanic activity in Hawai‘i is effusive, a major contribution of the past century of research at HVO has been to describe and quantify lava flow emplacement processes. Lava flow research has taken many forms; first and foremost it has been a collection of basic observational data on active lava flows from both Mauna Loa and Kīlauea volcanoes that have occurred over the past 100 years. Both the types and quantities of observational data have changed with changing technology; thus, another important contribution of HVO to lava flow studies has been the application of new observational techniques. Also important has been a long-term effort to measure the physical properties (temperature, viscosity, crystallinity, and so on) of flowing lava. Field measurements of these properties have both motivated laboratory experiments and presaged the results of those experiments, particularly with respect to understanding the rheology of complex fluids. Finally, studies of the dynamics of lava flow emplacement have combined detailed field measurements with theoretical models to build a framework for the interpretation of lava flows in numerous other terrestrial, submarine, and planetary environments. Here, we attempt to review all these aspects of lava flow studies and place them into a coherent framework that we hope will motivate future research.

Hawaii

The evolution of seismic monitoring systems at the Hawaiian Volcano Observatory

In the century since the Hawaiian Volcano Observatory (HVO) put its first seismographs into operation at the edge of Kīlauea Volcano&rsquo;s summit caldera, seismic monitoring at HVO (now administered by the U.S. Geological Survey [USGS]) has evolved considerably. The HVO seismic network extends across the entire Island of Hawai&lsquo;i and is complemented by stations installed and operated by monitoring partners in both the USGS and the National Oceanic and Atmospheric Administration. The seismic data stream that is available to HVO for its monitoring of volcanic and seismic activity in Hawai&lsquo;i, therefore, is built from hundreds of data channels from a diverse collection of instruments that can accurately record the ground motions of earthquakes ranging in magnitude from <1 to &ge;8. In this chapter we describe the growth of HVO&rsquo;s seismic monitoring systems throughout its first hundred years of operation. Although other references provide specific details of the changes in instrumentation and data handling over time, we recount here, in more general terms, the evolution of HVO&rsquo;s seismic network. We focus not only on equipment but also on interpretative products and results that were enabled by the new instrumentation and by improvements in HVO&rsquo;s seismic monitoring, analytical, and interpretative capabilities implemented during the past century. As HVO enters its next hundred years of seismological studies, it is well situated to further improve upon insights into seismic and volcanic processes by using contemporary seismological tools.

Hawaii

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1925

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1926

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1927

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1928

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1929

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii