This study presents a comprehensive group velocity map for the crustal
structure estimation in Northern Egypt using ambient noise tomography (ANT)
focusing on periods from 5 to 50 s. The study area is located in Northern Egypt
and encompasses regions bounded by the Red Sea to the east and the
Mediterranean Sea. We collected seismic ambient noise data from 24 broadband
seismic stations from July 2021 to June 2022, with an interstation spacing
ranging from 50 to 1000 km. Green’s Functions were derived from the
cross-correlation of the recorded data, resulting in 276 station pairs for
analysis. Accordingly, 100 to 250 reliable measurements were selected based on
the signal-to-noise ratio and the standard deviation of seasonal dispersion
curves. Utilizing the dense coverage of the ray paths enabled the generation of
group velocity maps with 5 to 30 s periods, offering spatial resolutions
between 50 and 400 km. The derived map revealed two distinct structural zones:
a high-velocity zone in the eastern part and a low-seismic velocity zone in the
western region. To further validate the results, one-dimensional shear wave
velocity profiles were inverted from the observed group velocities. We found that
the estimated Moho depths range from 40 km in the southwestern part to 35 km in
the north and eastern parts. Our results show that ANT is a powerful and advantageous approach,
particularly in nonactive seismic areas, effectively overcoming the challenges
encountered in conventional receiver function analysis and seismic tomography.