Tsunami Travel Time Constant Depth

Sum long-wave travel time over supplied constant-depth path segments; distances are explicit, no geodesic route construction, dispersion or arrival-warning guarantee.

Description

Long tsunami waves travel approximately at a depth-dependent shallow-water speed.

Long tsunami waves travel approximately at a depth-dependent shallow-water speed. A segmented path provides a simple travel-time budget.^[1]

Sum long-wave travel time over supplied constant-depth path segments; distances are explicit, no geodesic route construction, dispersion or arrival-warning guarantee.

When to use Tsunami Travel Time Constant Depth

Use this tool to sum long-wave travel time over supplied constant-depth path segments; distances are explicit, no geodesic route construction, dispersion or arrival-warning guarantee.

Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.

How to use Tsunami Travel Time Constant Depth and understand its results

Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.
Enter segmentLengthsM, segmentConstantDepthsM, gravityMPerSecondSquared using the field table and calculation rules, then run the tool.
Read segmentTravelTimesSeconds, totalTravelTimeSeconds. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
segmentLengthsM	Segment lengths m	list of number	Required
segmentConstantDepthsM	Segment constant depths m	list of number	Required
gravityMPerSecondSquared	Gravity m per second squared	number	Required

Align nonnegative lengths with positive constant segment depths and use positive gravity. Return each segment's seconds and their total.^[2]

Paired lists must be nonempty and have equal lengths.

time = Σ segment length/sqrt(gravity × segment depth)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
segmentTravelTimesSeconds	Segment travel times seconds	list of number
totalTravelTimeSeconds	Total travel time seconds	number

json

{
  "input": {
    "segmentLengthsM": [
      100,
      200
    ],
    "segmentConstantDepthsM": [
      10,
      40
    ],
    "gravityMPerSecondSquared": 10
  },
  "output": {
    "segmentTravelTimesSeconds": [
      10,
      10
    ],
    "totalTravelTimeSeconds": 20
  }
}

Limitations and assumptions

No geodesic route, dispersion or arrival-warning guarantee is provided.

Numbers and computed results must be finite; overflow produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Tsunami Shoaling Amplitude Deep To Shore: Apply linear long-wave Green shoaling plus supplied ray-width and energy-loss factors; excludes breaking, resonance and inundation and does not certify tsunami hazard. For a complementary task, use Wave Dispersion Relation Root Solver: Solve finite-depth linear dispersion omega²=g k tanh(kh) by bounded dimensionless bisection, returning phase/group speeds without deep/shallow aliases.

Further background: Tsunami propagation.

References

Tsunami propagation — NOAA
Tsunami Travel Time Constant Depth — tool.io

Similar or alternative tools

Tsunami Shoaling Amplitude Deep To Shore
Apply linear long-wave Green shoaling plus supplied ray-width and energy-loss factors; excludes breaking, resonance and inundation and does not certify tsunami hazard.
Wave Dispersion Relation Root Solver
Solve finite-depth linear dispersion omega²=g k tanh(kh) by bounded dimensionless bisection, returning phase/group speeds without deep/shallow aliases.