  We report measurements of the specific heat of the quantum spin liquid system
SrCu2(BO3)2 in continuous magnetic fields H of up to 33 T. The specific heat vs
temperature at zero field shows an anomaly at 8 K, marking the opening of a gap
in the spin singlet excitations. At fields H~12 T, we clearly see a second
anomaly that shifts to lower temperatures as H is increased. We attribute its
origin to single triplet excitations of the singlet dimer ground state. This
conclusion is supported by calculations of the specific heat, which reproduce
the experimental data, made using the finite temperature Lanczos method to
solve a Shastry-Sutherland Hamiltonian including nearest and next-nearest
neighbor Dzyaloshinsky-Moriya interactions. The parameters used to fit the data
are the exchange constants J = 74 K and J'/J = 0.62, and the
Dzyaloshinsky-Moriya coupling constants |D|=6.1K, and $|D'|=2.2K.
