  Liquid argon time projection chambers (LArTPCs) have been proposed as
neutrino detectors that combine both large sizes to maximize the number of
neutrino interactions and detailed recording of the interaction. The readout of
thousands of channels at MHz sampling rates produce images of the
neutrino-nucleus interaction with millimeter-scale resolution, enabling the
identification of the resulting particles and offering multiple handles to
measure their energies at the expense of large data rates. Continuous
acquisition of the LArTPC data is required to enable the use of high-latency
triggers for capturing non-accelerator-beam events. We describe the case of the
continuous readout of the MicroBooNE LArTPC, that grants the possibility of
acquiring the neutrino burst from a supernova using the SNEWS (Supernova Early
Warning System) alert as delayed trigger. The continuous data acquisition is
accomplished by using real-time compression algorithms (zero suppression and
Huffman compression) implemented in an FPGA in the readout electronics.
