A low-order model of the Heinrich Event Cycle


  • D. R. MacAyeal


If Heinrich events result from free oscillations in the size and basal melting conditions of the Laurentide ice sheet, a rigorous quantitative analysis of ice sheet physics should describe their dynamics. To explore this possibility, I exploit two characteristic timescales which arise from ice sheet physics to construct a relaxation oscillator model of the North Atlantic's Heinrich events. The numerical implementation of this model confirms the notion that the periodicity of Heinrich events (approximately 7,000 years) is determined by the gross properties of a steady glacial climate (e.g., an annual average sea level temperature of −10° C and an adiabatic lapse rate).