Published online by Cambridge University Press: 05 March 2013
Overview
Magma–water interaction is an unavoidable consequence of the hydrous nature of the Earth’s crust, and may take place in environments ranging from submarine to desert regions, producing volcanic features ranging from passively effused lava to highly explosive events. Hydrovolcanism is the term that describes this interaction at or near the Earth’s surface, and it encompasses the physical and chemical dynamics that determine the resulting intrusive or extrusive behavior, and the character of eruptive products and deposits. The development of physical theory describing the energetics and the hydrodynamics (dynamics of fluids and solids at high strain rates) of magma–water interaction relies on an understanding of the physics of water behavior in conditions of rapid heating, the physics of magma as a material of complex rheology, and the physics of the interaction between the two, as well as detailed field observations and interpretation of laboratory experiments. Of primary importance to address are the nature of heat exchange between the magma and water during interaction, the resulting fragmentation of the magma, and the constraints on system energetics predicted by equilibrium and non-equilibrium thermodynamics. Taken together, these approaches elucidate the relationships among aqueous environment, interaction physics, and eruptive phenomena and landforms.
Introduction: magma and the hydrosphere
The vast majority of volcanic eruptions take place under water because most volcanism concentrates at mid-oceanic ridges where new oceanic crust is produced. By definition, every kind of extrusive subaqueous volcanism on Earth is hydrovolcanic since some degree of water interaction must take place. The hydrosphere also exists in continental areas, as the consequence not only of lakes and rivers, but also of groundwater and hydrous fluids that circulate in joints and faults in the upper crust and fill pore space in sedimentary rocks. Such locations are typically referred to as geohydrological environments. As a consequence, subaerial volcanism is commonly influenced by magma–water interaction. Chapter 12 describes deep-sea eruptions in greater detail, whereas this chapter focuses on magma–water interaction in surface and near-surface environments.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.