Air carrier first officer reported while on base turn on approach to EWR Runway 29 descending below the profile resulting in flight towards terrain and ATC issuing a low altitude alert. The flight crew corrected the descent profile and landed safely.

Narrative

On Day 0; while operating from IAD into Newark (EWR); reported winds were 290° at 22 knots; gusting 32 knots. Newark was landing Runway 29 via the RNAV (GPS) W approach. ATC instructed us to maintain 170 knots until a 5-mile final; which limited our ability to configure the aircraft as early as we normally would on an RNAV approach.At approximately 5 miles from the runway; the Captain directed that we become fully configured. I called for gear down and flaps 30. While the landing gear was in transit; ATC instructed us to square the final due to an ATR ahead that was flying slower than anticipated. I disconnected the autopilot and began maneuvering to comply with the instruction.During the maneuver to square the base; my attention was divided between visually acquiring the ATR and managing the aircraft's energy state. At that time; the aircraft was slightly high on profile. While lowering the nose to regain the proper descent path; airspeed increased more rapidly than intended as my focus remained outside acquiring the traffic. To arrest the increasing airspeed; I deployed the speedbrakes; which reduced airspeed but temporarily increased the descent rate.Around this time; ATC issued a Low Altitude Alert due to our descent rate and proximity to the bridge. At the time of the alert; the aircraft was establishing the proper vertical profile. I immediately verified altitude; arrested the descent; and stabilized the aircraft.After arresting the descent with the aircraft stabilized; we then selected flaps 45 and completed the Before Landing Checklist.The remainder of the approach was flown visually using the PAPI to maintain the proper glidepath. The landing was uneventful; and we taxied to the gate without further incident.