  Extracting Empirical Green's Functions (EGFs) by cross-correlating ambient
seismic noise or coda, considered as an efficient approach of retrieving new
response inside the media of two receivers, has been developed well in the past
two decades. However, EGFs emerge with high Signal-to-Noise Ratios (SNRs),
which needs us to stack a large number of cross-correlations. Here, we retrieve
EGFs with high SNRs from ambient seismic noise released by hurricane Dorian
moving along the eastern coast of the United States during 3 days in Sept 2019.
We systematically analyze the energy sources of seismic noise records with
time-frequency analysis and beam-forming. We find that the energy exhibits very
strongly when hurricane Dorian progresses along the coast from 4th to 6th Sept.
Our results suggest that EGFs exhibit strong directionality and only emerge in
the negative part of cross-correlation time functions due to the noise sources
of Dorian. We extract clear multimodal dispersion curves of Rayleigh waves from
retrieved EGFs. Our results, indeed, reveal that multimodal dispersion curves
pf Rayleigh wave could be extracted from ambient seismic noise excited by
Dorian for several days or even a single day, which means that we enlarge the
seismic data sets for the future work of investigating shear velocity
structures of the Earth's crust and upper mantle and understanding our planet
more deeply.
