Dedication

Caudron, C., Ohba, T. & Capaccioni, B. Geochemistry and geophysics of active volcanic lakes: an introduction

Acidic lakes

van Hinsberg, V., Vigouroux, N., Palmer, S., Berlo, K., Mauri, G., Williams-Jones, A., Mckenzie, J., Williams-Jones, G. & Fischer, T. Element flux to the environment of the passively degassing crater lake-hosting Kawah Ijen volcano, Indonesia, and implications for estimates of the global volcanic flux

Gunawan, H., Caudron, C., Pallister, J., Primulyana, S., Christenson, B., Mccausland, W., van Hinsberg, V., Lewicki, J., Rouwet, D., Kelly, P., Kern, C., Werner, C., Johnson, J. B., Utami, S. B., Syahbana, D. K., Saing, U., Suparjan, Purwanto, B. H., Sealing, C., Cruz, M. M., Maryanto, S., Bani, P., Laurin, A., Schmid, A., Bradley, K., Nandaka, I. G. M. A. & Hendrasto, M. New insights into Kawah Ijen’s volcanic system from the wet volcano workshop experiment

Caudron, C., Mauri, G., Williams-Jones, G., Lecocq, T., Syahbana, D. K., De Plaen, R., Peiffer, L., Bernard, A. & Saracco, G. New insights into the Kawah Ijen hydrothermal system from geophysical data

Rouwet, D., Mora-Amador, R., Ramírez-Umañ A, C. J., González, G. & Inguaggiato, S. Dynamic fluid recycling at Laguna Caliente (Poás, Costa Rica) before and during the 2006–ongoing phreatic eruption cycle (2005–10)

Capaccioni, B., Rouwet, D. & Tassi, F. HCl degassing from extremely acidic crater lakes: preliminary results from experimental determinations and implications for geochemical monitoring

Agusto, M. R., Caselli, A., Daga, R., Varekamp, J., Trinelli, A., Afonso, M. D. S., Velez, M. L., Euillades, P. & Guevara, S. R. The crater lake of Copahue volcano (Argentina): geochemical and thermal changes between 1995 and 2015

Hernández, P. A., Melián, G. V., Somoza, L., Arpa, M. C., Pérez, N. M., Bariso, E., Sumino, H., Padrón, E., Varekamp, J. C., Albert-Beltran, J. & Solidum, R. The acid crater lake of Taal Volcano, Philippines: hydrogeochemical and hydroacoustic data related to the 2010–11 volcanic unrest

Rouwet, D. & Iorio, M. The sedimentation of Suminagashi-like floating clay patterns at El Chichón crater lake (Chiapas, Mexico)

Neutral lakes

Kozono, T., Kusakabe, M., Yoshida, Y., Ntchantcho, R., Ohba, T., Tanyileke, G. & Hell, J. V. Numerical assessment of the potential for future limnic eruptions at lakes Nyos and Monoun, Cameroon, based on regular monitoring data

Ohba, T., Ooki, S., Oginuma, Y., Kusakabe, M., Yoshida, Y., Ueda, A., Anazawa, K., Saiki, K., Kaneko, K., Miyabuchi, Y., Issa, Aka, F., Fantong, W., Ako, A., Tanyileke, G. & Hell, J.V. Decreasing removal rate of the dissolved CO2 in Lake Nyos, Cameroon, after the installation of additional degassing pipes

Saiki, K., Kaneko, K., Ohba, T., Sanemasa, M., Kusakabe, M., Ntchantcho, R., Fouepe, A., Tanyileke, G. & Hell, J. V. Vertical distribution of dissolved CO2 in lakes Nyos and Monoun (Cameroon) as estimated by sound speed in water

Sanemasa, M., Saiki, K., Kaneko, K., Ohba, T., Kusakabe, M., Ntchantcho, R., Fouepe, A., Tanyileke, G. & Hell, J. V. A new method to determine dissolved CO2 concentration of lakes Nyos and Monoun using the sound speed and electrical conductivity of lake water

Yoshida, Y., Kusakabe, M., Issa, Ohba, T., Tanyileke, G. & Hell, J. V. Decreasing capability of the degassing systems at lakes Nyos and Monoun (Cameroon): a new gas removal system applied to Lake Monoun to prevent a future limnic eruption

Ozawa, A., Ueda, A., Fantong, W. Y., Anazawa, K., Yoshida, Y., Kusakabe, M., Ohba, T., Tanyileke, G. & Hell, J. V. Rate of siderite precipitation in Lake Nyos, Cameroon

Zimmer, M., Tassi, F., Vaselli, O., Kujawa, C., Cabassi, J. & Erzinger, J. The gas membrane sensor (GMS) method: a new analytical approach for real-time gas concentration measurements in volcanic lakes

Melián, G., Somoza, L., Padrón, E., Pérez, N. M., Hernández, P. A., Sumino, H., Forjaz, V. H. & França, Z. Surface CO2 emission and rising bubble plumes from degassing of crater lakes in São Miguel Island, Azores

Lefkowitz, J. N., Varekamp, J. C., Reynolds, R. W. & Thomas, E. A tale of two lakes: the Newberry Volcano twin crater lakes, Oregon, USA

Index

During the 20th century, subaqueous eruptions accounted for just 8% of volcanic events, but led to 20% of the total fatalities resulting from them. This Geological Society of London Special Publication is therefore welcome in highlighting a geohazard about which few geologists may be familiar. The book is dedicated to one of the co-editors, Professor Bruno Capaccioni, who was killed in a car accident before publication. As with most GSL Special Publications, this volume is a col- lection of research papers. It is divided into two main sections, acidic lakes and neutral lakes, and is slightly unusual in that many of the papers relate to just two volcanic events: the erup-
tions at Lake Nyos and Lake Monoun in Cameroon.

In 1986, more than 1,800 people were killed in a single event at Nyos, owing to carbon monoxide poisoning. This hitherto relatively little-known volcanic lake became the focus of much attention regarding the cause of the CO2 eruption. The papers discuss the debate regarding the origin of the CO2 and the research undertaken into the geochemistry and hydrothermal
system feeding the lake. Other papers outline the various steps that had to be taken to ‘degas’ the lake to safe levels to avoid further eruptions. These have been successful and monitoring on a regular basis takes place to warn of future, potentially dangerous, new gas build up.

A similar event had taken place at Lake Monoun two years earlier, but the death toll was lower (37) and did not attract the same attention as Nyos. Read together, the research papers form an excellent account of the geological detective work at Nyos, how limnic eruptions occur, mitigation and identification of possible further sites where they may occur. Other active lakes are also covered, such as the passively degassing Kawah Ijen in Indonesia, the acid crater lake at Taal Volcano in the Philippines and a particularly interesting paper about the Newberry Volcano twin crater lakes in Oregon, USA, which, despite their being within a single caldera and having divided 7ka ago, have different geochemical characteristics.

Overall, this book represents the latest in research into an over- looked topic. It offers an introduction to crater lake basics and more but, by telling the Nyos story, it provides a framework resulting in an extremely interesting and informative book. The reviewer feels that this would be an excellent starting point for students looking for a topic for their SXG paper.