The Jargon File (version 4.4.7, 29 Dec 2003):

netburp
 n.

    [IRC] When netlag gets really bad, and delays between servers exceed a
    certain threshold, the IRC network effectively becomes partitioned for a
    period of time, and large numbers of people seem to be signing off at the
    same time and then signing back on again when things get better. An
    instance of this is called a netburp (or, sometimes, netsplit).


The Free On-line Dictionary of Computing (30 December 2018):

netburp
netsplit

    (Or "netsplit") When netlag gets really
   bad, and delays between IRC servers exceed a certain
   threshhold, the network effectively becomes partitioned for a
   period of time, and large numbers of people seem to be signing
   off at the same time and then signing back on again when
   things get better.  An instance of this is called a "netburp"
   (or, sometimes, netsplit).

   [Jargon File]

   (1996-06-04)