Zachariae Isstrom glacier – © Christoph Horman/imagico.de Scientists say the Zachariae Isstrom glacier has now become detached from a stabilising sill and is losing ice at a rate of 4.5bn tonnes a year. – © Christoph Horman/imagico.de Scientists say the Zachariae Isstrom glacier has now become detached from a stabilising sill and is losing ice at a rate of 4.5bn tonnes a year. – © Christoph Horman/imagico.de 00