Which type of seismic wave is highlighted in the image​

Seismic waves are the fundamental energy carriers generated by earthquakes, and understanding them is essential for designing resilient infrastructure. For US pipe engineering firms like Fluxiss, analyzing seismic wave propagation in earth ensures pipelines and structural systems can withstand the destructive forces of ground motion intensity. The question of which type of seismic wave is highlighted in the image often arises during hazard assessments, and identifying the correct wave is important for seismic modeling for structural design, earthquake load simulation, and mitigation strategies.

Seismic waves are generally divided into body waves and surface waves, each with distinct characteristics. Body waves, such as P-waves (compressional) and S-waves (shear), travel through the Earth’s interior, while surface waves, including Rayleigh and Love waves, move along the Earth’s crust. In this blog, we will break down these types of seismic waves and their properties, highlight their engineering relevance for pipelines, and demonstrate how Fluxiss applies advanced modeling to ensure safe infrastructure.

Understanding P-Wave and S-Wave Difference

One of the first steps in seismic analysis is distinguishing between P-wave and S-wave difference.

P-Waves (Primary/Compressional Waves)

These waves compress and expand the medium in the direction of propagation, similar to a slinky being pushed and pulled. They travel at 5–8 km/s in the crust and are the first to arrive at seismic stations. P-waves move through solids, liquids, and gases, making them invaluable for early warning systems such as the USGS ShakeAlert.

S-Waves (Secondary/Shear Waves)

S-waves move perpendicular to the propagation direction, creating oscillations that stress and fracture the material. With velocities ranging from 3 to 4.5 km/s in the crust, they cause significant structural rocking and do not pass through liquids, forming the S-wave shadow zone detectable in the Earth’s interior.

For pipeline engineering, Fluxiss uses these wave distinctions to calculate axial and bending stresses during seismic events. Accurate modeling of P- and S-wave difference informs seismic vibration analysis for pipelines, helping prevent rupture or excessive strain in buried infrastructure.

For a deeper look at wave mechanics, studies by the USGS on historic earthquakes provide valuable real-world examples.

Surface Seismic Waves Examples

While body waves are critical for early detection, surface seismic waves examples often account for most infrastructure damage. Two major types dominate surface effects:

Rayleigh Waves

Particles move in elliptical retrograde motion, causing vertical and horizontal shaking. These waves are slower (2–4 km/s) but produce significant ground roll, amplifying damage in soft soils. Historical events like the 1906 San Francisco earthquake demonstrate their destructive impact.

Love Waves

Featuring purely horizontal shear motion perpendicular to propagation, Love waves generate strong lateral forces. They played a major role in rupturing pipelines during the 2023 Turkey-Syria earthquake and are a key consideration in seismic vibration analysis for pipelines.

US engineering practices, as outlined in FEMA P-58 and ASCE 7-22, emphasize integrating these surface effects into probabilistic seismic hazard analysis (PSHA) for both urban and industrial zones.

Seismic Waves Diagram Explanation

A typical seismic waves diagram explanation helps engineers visualize how energy propagates from the earthquake hypocenter to the surface.

• Body waves radiate in spherical patterns, refracting at boundaries like the Moho (crust-mantle) and outer core. P-waves continue through both solids and liquids, while S-waves are blocked by liquid layers.
• Surface waves travel along the crust, with Rayleigh waves moving in elliptical paths and Love waves in horizontal shear.

This USGS document illustrates these paths, providing crucial insights for seismic modeling for structural design. Fluxiss incorporates such visualizations into site-specific hazard assessments, using software like SPECFEM3D to simulate wave propagation velocity and amplitudes for pipeline systems.

Rayleigh and Love Waves Motion

Understanding Rayleigh and Love waves motion is critical for pipe engineering:

• Rayleigh Waves: Cause vertical and horizontal displacement, increasing stress on tall structures and flexible pipelines.
• Love Waves: Impose lateral shear, affecting buried pipelines and jointed systems.

Animations from IRIS and Purdue University demonstrate how these waves interact with structures. Fluxiss applies these motion profiles to earthquake load simulation and structural response models, ensuring designs account for both amplitude and frequency effects.

Types of Seismic Waves and Their Properties

A detailed look at types of seismic waves and their properties provides the foundation for engineering analysis:

These types of seismic waves influence design strategies in seismic modeling for structural design and pipeline response to seismic motion. At Fluxiss, engineers integrate these properties into finite element analysis (FEA) using tools like CAESAR II and ANSYS for 2025 standards.

Earthquake Wave Motion Animation

Animations of earthquake wave motion animation clarify how energy travels through the Earth:

• P-waves compress the medium longitudinally.
• S-waves shear perpendicular to propagation.
• Rayleigh waves create rolling motion, while Love waves produce lateral sliding.

These visualizations aid in how seismic waves affect structures, guiding design decisions to mitigate resonance and amplification. Fluxiss leverages both time-history analysis and response spectrum analysis to simulate these motions for pipelines and structural systems.

Seismic Wave Propagation in Earth

Seismic wave propagation in earth depends on material properties:

• Velocity increases with depth (Vp ~6–13 km/s, Vs ~3.5–7 km/s).
• Waves refract, reflect, and attenuate based on density and elastic moduli.
• Low-velocity zones (LVZs) in the upper mantle can amplify surface shaking.

At Fluxiss, engineers use 3D velocity models and probabilistic site-specific hazard simulations to predict ground motion intensity and stress distribution on pipelines. This ensures compliance with ASCE 7-22 and FEMA P-695 design requirements.

Body Waves vs Surface Waves

Understanding body waves vs surface waves helps prioritize mitigation strategies:

While body waves reveal hypocenter and travel-time information, surface waves often cause 70–80% of damage in populated areas. Fluxiss designs pipelines to withstand both types, incorporating shear wave movement and compressional wave in earthquakes into modeling.

How Seismic Waves Affect Structures

Seismic shaking induces inertial forces: F=m×aF = m \times aF=m×a. S-waves and surface waves can resonate with a structure’s natural frequency, amplifying damage. Soil type, proximity, and wave duration are key factors. Fluxiss implements earthquake load simulation and seismic vibration analysis for pipelines to limit stress and deformation, often using base isolation and flexible joints for protection.

Seismic Vibration Analysis for Pipelines

Fluxiss performs comprehensive vibration analysis using:

• Response Spectrum Analysis: Evaluates modal stresses on pipelines.
• Time-History Analysis: Simulates real-time wave effects on soil-pipe interaction.
• Strain-Based Design: Limits longitudinal/hoop strain per API 1173 standards.

This approach ensures pipeline integrity even under extreme surface wave amplification, mitigating risks identified in events like San Francisco 1906.

Conclusion – Discover How Fluxiss Protects Your Infrastructure

At Fluxiss, understanding types of seismic waves is not just academic—it’s central to protecting pipelines and infrastructure from earthquakes. By integrating seismic wave propagation in earth, earthquake wave motion animation, and Rayleigh and Love waves motion into engineering simulations, Fluxiss ensures designs meet 2025 standards for durability and resilience. For comprehensive seismic assessments, visit or contact us to discuss project-specific solutions.