Surface heat flow density at the phlegrean fields caldera (SOUTHERN ITALY)

The Phlegrean Fields area is a Holocene caldera located west of Naples\ southern Italy[ The recent post!caldera activity is characterized by several eruptive centers inside the collapsed area[ In order to investigate the still active volcanic processes\ surface heat ~ow measurements were carried out in 0884 in 29 sites of the Phlegrean Fields\ and a heat ~ow map compiled[ Filtering of the map reveals some well!de_ned anomalies superimposed on a general southward!increasing trend[ Local anomalies are related to small magma bodieswhereas the observed general trend has been attributed to the e}ect of ground! water ~ow[ This e}ect was calculated and removed[ The undisturbed mean value of the surface heat ~ow density in the eastern sector is 038mW:m1\ which is above the regional value of 74mW:m1 assigned to the eastern part of the Tyrrhenian Sea\ and which is probably in~uenced by a very large\ deep magmatic body[ 0887 CNR[ Published by Elsevier Science Ltd[ All ri`hts reserved