---
title: Geophysical Weekly
type: L2-brief
theme: geophysical
week: 2026-W34
updated: 2026-08-17T09:00:00Z
sources: [earthquakes]
license: CC-BY-4.0
attribution: azimuth (HemySphere doctrine demonstrator) — see CREDITS.md for upstream sources
---

# Geophysical Weekly

> Synthesised from the week's L1 source notes under `../01 Sources/`. The `azimuth-curator`
> fleet role evolves this single note in place each week. azimuth reports **observed**
> seismicity from the USGS feed — what was recorded, never what will happen. Every claim
> links to the L1 note it rests on. (This cycle absorbs the 2026-08-17 ingest, covering the
> rolling window to 2026-08-17.)

## This week at a glance

- The USGS feed recorded **137** magnitude-4.5-or-greater earthquakes in the rolling window
  retrieved 2026-08-17, of which **57 were M5+**, **six reached M6+** and **two reached M7** —
  the overall count rose from the 08-16 window (128 / 51 / 6 / 2), but the M6+ and M7+ tallies
  held exactly steady: no fresh major entered, and the same six strong events carry the window
  forward ([[earthquakes]]).
- The window's headline remains the shallow **M7.7 68 km NNW of Ende, Indonesia** (2026-08-14,
  10 km) — still the strongest event recorded, anchoring a Flores offshore swarm that has grown
  to **57 events** (from 42) across the Ende, Ruteng and Labuan Bajo sub-clusters; the deep
  **M7.4 5 km S of San José del Palmar, Colombia** (2026-08-10, 110 km) remains the window's
  second major, now within about five hours of the rolling window's 7-day cutoff
  ([[earthquakes]]).
- Below the two M7s the same four M6+ carry over unchanged: an **M6.9** 15 km NNW of
  Pematangsiantar, Indonesia (2026-08-15, 173 km — a deep Sumatra event), an **M6.1** 56 km NNE
  of Port-Olry, Vanuatu (2026-08-16, 188 km), the shallow **M6.1** 58 km N of Ende (2026-08-14,
  10 km) on the Flores swarm, and an **M6.0** in the South Sandwich Islands region (2026-08-12,
  10 km) ([[earthquakes]]).

## Largest events

- The window's strongest is the shallow **M7.7 68 km NNW of Ende, Indonesia** (2026-08-14, 10 km)
  — a crustal event north of Flores that heads a swarm now sized at 57 events (up from 42), with
  an M5.9, then M5.7 / M5.6 / M5.5 shocks logged across Ende, Ruteng and Labuan Bajo, most about
  10 km deep ([[earthquakes]]).
- The window's second M7 is the deep **M7.4 5 km S of San José del Palmar, Colombia** (2026-08-10,
  110 km) — an intraslab event beneath the northern Andes, well off the western-Pacific arcs that
  dominate the rest of the window; it now sits only about five hours inside the rolling window's
  7-day cutoff ([[earthquakes]]).
- Below the two majors sit four M6+, unchanged from 08-16: the **M6.9** 15 km NNW of
  Pematangsiantar, Indonesia (2026-08-15, 173 km deep), the **M6.1** 56 km NNE of Port-Olry,
  Vanuatu (2026-08-16, 188 km deep), the shallow **M6.1** 58 km N of Ende (2026-08-14, 10 km) on
  the Flores swarm, and the **M6.0** South Sandwich Islands region (2026-08-12, 10 km)
  ([[earthquakes]]).

## Where the activity clustered

- **Indonesia dominated the count at 70 events** (from 54), more than eleven times the next
  country — driven by the growing Ende / Ruteng / Labuan Bajo Flores swarm (57 events, from 42,
  capped by the M7.7) plus the deep Pematangsiantar M6.9 and a small Banda Sea cluster. **Russia
  (6)** and **Papua New Guinea (6, from 5)** followed, then **Vanuatu (5)** and **Japan (5)**;
  the **Philippines** eased sharply to **(4)** from 10 ([[earthquakes]]).
- The dominant feature remains the **Ende / Flores offshore swarm** — now a 57-event shallow
  (mostly 10 km) cluster spanning Ende, Ruteng and Labuan Bajo, capped by the M7.7 and its M6.1 —
  still the strongest sequence in the window; the Colombia M7.4 and the deep Sumatra M6.9 stand
  apart from it as isolated majors ([[earthquakes]]).

## Depth profile

- The shallow proportion held high: **81 of the 137 events sit at ≤15 km** (from 73 of 128),
  including nearly the whole Ende / Flores swarm. The deep-focus list still runs on the Vanuatu
  and Fiji slabs — the deepest recorded event is unchanged, a **655.7 km** shock 173 km ENE of
  Sola, Vanuatu, followed by a **640.5 km** focus 180 km NE of Sola and a **570.8 km** event east
  of Levuka, Fiji; a fresh **564.4 km** focus 215 km ENE of Levuka, Fiji entered on today's pull
  ([[earthquakes]]).

## Reading the week

- The strong-event tally held steady in composition even as volume grew: **137 M4.5+ (57 M5+, 6
  M6+, 2 M7+)** to 2026-08-17, up from 128 (51/6/2) on 08-16, but the M6+/M7+ line-up is
  unchanged — the same shallow **M7.7 off Ende, Indonesia** (2026-08-14) and deep **M7.4 in
  Colombia** (2026-08-10), plus the same four M6+ (Pematangsiantar, Port-Olry, Ende and South
  Sandwich), with no fresh major on this pull. The Colombia M7.4 now sits only about five hours
  inside the window's 7-day cutoff. The growth came from the Flores swarm, which expanded to 57
  events (from 42) across Ende, Ruteng and Labuan Bajo, lifting Indonesia's count to 70 (from 54)
  and its lead over the next country past elevenfold. 81 of 137 shocks were shallow ≤15 km (from
  73 of 128) and the deep-slab list held at a 655.7 km Vanuatu focus. azimuth records what the
  instruments measured — magnitude, location, depth, time — and stops there, making no forecast
  of what the Ende sequence or the Colombia event's window position does next ([[earthquakes]]).

## Changelog

- 2026-08-17 — daily-ingest synthesis (2026-W34): the rolling window to 2026-08-17 rose to 137 M4.5+ (57 M5+, 6 M6+, 2 M7+ — from 128/51/6/2 on 08-16); the M6+/M7+ composition held exactly steady (same two majors, same four M6+), no fresh major entered. The Ende/Ruteng/Labuan Bajo Flores swarm grew to 57 events (from 42: 25 Ende + 25 Ruteng + 7 Labuan Bajo), lifting Indonesia's count to 70 (from 54); the carried M7.4 Colombia (2026-08-10) now sits only about five hours inside the window's 7-day cutoff. Deepest event held at 655.7 km (Sola, Vanuatu); 81 of 137 shocks shallow ≤15 km (from 73/128). Updated the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-08-16 — daily-ingest synthesis (2026-W33): absorbed the 2026-08-07 through 2026-08-16 USGS pulls after a curator gap; the rolling window to 2026-08-16 reads 128 M4.5+ (51 M5+, 6 M6+, 2 M7+ — from 138/66/1/0 on 08-01), a sharp step up in strong events. Two majors entered: a shallow M7.7 68 km NNW of Ende, Indonesia (2026-08-14, 10 km), now the window's strongest and the anchor of a ~22-event Flores aftershock swarm, and a deep M7.4 5 km S of San José del Palmar, Colombia (2026-08-10, 110 km). Four more M6+ — M6.9 Pematangsiantar Indonesia (deep, 08-15), M6.1 Port-Olry Vanuatu (deep, 08-16), M6.1 Ende (shallow, 08-14) and M6.0 South Sandwich Islands (08-12). Indonesia led the count at 54; deepest event a 655.7 km Sola, Vanuatu focus; 73 of 128 shocks shallow ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-06-18 — first Geophysical Weekly cycle: wrote the at-a-glance, largest-events,
  clustering, depth and reading sections from the live 2026-06-18 USGS ingest (111 M4.5+
  events, max M6.7 Palu; Philippines/Indonesia-led). Observed-only framing per the
  report-observed-not-predicted caution.
- 2026-06-20 — daily-ingest refresh from the live 2026-06-20 USGS day (110 M4.5+, 40 M5+, 6
  M6+; max still M6.7 Palu). Recorded the week's new feature — a Kamchatka sequence off
  Petropavlovsk-Kamchatsky peaking at M6.6 then M6.0 — across the at-a-glance, largest-events,
  clustering and reading sections; the M6+ count rose from four to six. Updated the deepest
  event to a 606 km Fiji-region focus. Observed-only framing held.
- 2026-06-23 — daily-ingest flowback (2026-W26): refreshed from the live 2026-06-23 USGS day,
  the seven days to 2026-06-23 (121 M4.5+, 37 M5+, 5 M6+; max M6.7 Palu now at the trailing edge
  of the rolling window). The Kamchatka offshore swarm (M6.6/M6.0 plus M5.7–M5.8 aftershocks,
  ~11 events) became the dominant strong cluster and a new Tonga–Kermadec string opened on the
  southwest-Pacific margin; rewrote the at-a-glance, largest-events, clustering and reading
  sections accordingly. Deepest event held at the 606 km Fiji-region focus. Observed-only
  framing held.
- 2026-06-25 — daily-ingest flowback (2026-W26): refreshed from the live 2026-06-25 USGS day,
  the seven days to 2026-06-25 (101 M4.5+, 32 M5+, 5 M6+ — and two M7+ for the first time in
  weeks). The new headline is a shallow M7.5/M7.2 doublet SE of Yumare, Venezuela (2026-06-24),
  the strongest recorded since the brief began and off the usual western-Pacific arcs, plus an
  M6.9 ENE of Kuji, Japan the same day; the Kamchatka swarm receded to the trailing edge.
  Rewrote the at-a-glance, largest-events, clustering and reading sections around the
  continental-margin doublet and the overall count falling even as released energy rose.
  Deepest event held at the 606 km Fiji-region focus. Observed-only framing held ([[earthquakes]]).
- 2026-06-26 — daily-ingest flowback (2026-W26): refreshed from the live 2026-06-26 USGS day,
  the seven days to 2026-06-26 (98 M4.5+, 30 M5+, 3 M6+, 2 M7+). The Yumare, Venezuela M7.5/M7.2
  doublet and the Kuji, Japan M6.9 (all 2026-06-24) remain the only M6+ shocks in the window;
  last week's Kamchatka M6.6/M6.0 pair rolled off, dropping the M6+ count from five to three.
  Japan rose to eight events (Kuji sequence + an M5.8 at Yokoshiba) and an isolated M5.59 hit
  Redwood Valley, California. Updated the at-a-glance, largest-events, clustering and reading
  sections; deepest event held at the 606 km Fiji-region focus. Observed-only framing held
  ([[earthquakes]]).
- 2026-06-30 — daily-ingest flowback (2026-W27): refreshed from the live 2026-06-30 USGS day,
  the seven days to 2026-06-30 (102 M4.5+, 35 M5+, 5 M6+, 2 M7+). The M6+ count rose from three
  to five as two fresh majors entered — an M6.5 WSW of Sarangani, Philippines (2026-06-26) and a
  deep M6.1 S of Jurm, Afghanistan (2026-06-27, 199 km) — while the Yumare M7.5/M7.2 doublet and
  the Kuji M6.9 (all 2026-06-24) held on at the trailing edge and will age out next cycle. The
  Philippines led the count at 16 (Catuday + Sarangani), a Japanese Sanriku sequence logged
  M5.7–M5.8, and eastern-Pacific M5.5/M5.59 events hit off Oregon and at Redwood Valley,
  California. Deepest event updated to a 617 km Fiji-region focus. Observed-only framing held
  ([[earthquakes]]).
- 2026-07-02 — weekly synthesis (2026-W27): absorbed the 2026-07-01 and 2026-07-02 ingest days,
  the seven days to 2026-07-02 (100 M4.5+, 37 M5+, 4 M6+, 0 M7+). The Yumare, Venezuela
  M7.5/M7.2 doublet and the Kuji, Japan M6.9 aged out of the rolling window as the prior cycle
  anticipated, taking M7+ to zero; two fresh M6.0s entered — 49 km E of Noda, Japan
  (2026-07-01, 44 km), capping the building Sanriku sequence, and a shallow one 75 km SSW of
  El Progreso, Mexico (2026-06-30, 10 km). Japan took the count lead at 14 (Noda sequence),
  a new six-event South Sandwich Islands string opened (M4.9–M5.3), and the deep list
  thickened around the Fiji slab (six foci below 500 km, deepest 617 km). Rewrote the
  at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing
  held ([[earthquakes]]).
- 2026-07-13 — weekly synthesis (2026-W29): absorbed the 2026-07-06 through 2026-07-13 ingest
  days after an 11-day curator gap, the seven days to 2026-07-13 (98 M4.5+, 36 M5+, 2 M6+, 0
  M7+). Last cycle's four M6+ shocks (the M6.5 Sarangani, the deep M6.1 Jurm, the M6.0 Noda and
  the M6.0 El Progreso) all aged out; two fresh M6.4s entered, both shallow and in the Southern
  Hemisphere — 191 km SE of Lorengau, Papua New Guinea (2026-07-13, 10 km) and the South Sandwich
  Islands region (2026-07-11, 26 km). Indonesia led the count at 15 (ahead of the Philippines 9,
  China 7, Vanuatu 7), the South Sandwich string persisted at 4, and the deep-focus list thinned
  to a single sub-500 km event (an M4.5 at 561 km, Fiji region) as 51 of 98 shocks were shallow
  ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections.
  Observed-only framing held ([[earthquakes]]).
- 2026-07-15 — daily-ingest flowback (2026-W29): refreshed from the live 2026-07-14/15 USGS days,
  the seven days to 2026-07-15 (104 M4.5+, 41 M5+, 4 M6+, 0 M7+). The M6+ count doubled from two
  to four: an **11-event shallow swarm southeast of the Loyalty Islands** capped at M6.3
  (2026-07-13) and an M6.2 struck 34 km WSW of Sarangani, Philippines (2026-07-14, 68 km),
  joining the carried M6.4 pair (Lorengau PNG / South Sandwich). The Philippines took the count
  lead at 15 from Indonesia (12), the Loyalty swarm logged 11, and a fresh Kamchatka string
  (M5.1/M4.9/M4.7, Vilyuchinsk) opened on 2026-07-15. Deep-focus list: two Fiji foci (574/561 km);
  57 of 104 shocks shallow ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and
  reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-07-18 — daily-ingest synthesis (2026-W29): absorbed 2026-07-16 and 2026-07-17 USGS pulls; rolling window grew to 111 M4.5+ (43 M5+, 4 M6+, 0 M7+); same four M6+ in window (no new majors); leading-edge additions: 9-event southern Mid-Atlantic Ridge shallow cluster (M4.7–M5.3), M5.9 at Te Anau, New Zealand (76 km), M5.2 at Shwebo, Myanmar; Philippines rose to 17-event count leader; deepest event updated to 625.6 km Fiji-region focus ([[earthquakes]]).
- 2026-07-21 — daily-ingest synthesis (2026-W30): absorbed the 07-18 through 07-20 USGS pulls; the rolling window to 2026-07-20 grew to 149 M4.5+ (61 M5+, 4 M6+, 1 M7+). The headline is a major Mexican Pacific-coast sequence: an M7.3 58 km WSW of Puerto Madero, Mexico (2026-07-17, 18.6 km) — the first M7+ since the late-June Yumare M7.5 — capping a dense Chiapas offshore swarm that also produced an M6.0 (2026-07-17) and dozens of M4.5–M5.5 aftershocks; the pair entered the feed on the 07-18 ingest, after the prior brief's cutoff. Mexico took the count lead at 36 events; the carried Loyalty-Islands M6.3 (07-13) and Sarangani M6.2 (07-14) remain the other majors; deepest event held at the 625.6 km Fiji focus. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-07-23 — daily-ingest synthesis (2026-W30): absorbed the 07-21 through 07-23 USGS pulls; the rolling window to 2026-07-23 edged up to 155 M4.5+ (59 M5+, 2 M6+, 1 M7+). The M6+ count halved from four to two as the Loyalty-Islands M6.3 (07-13) and Sarangani M6.2 (07-14) aged off the trailing edge, leaving both remaining majors on the single Chiapas trend — the carried M7.3 58 km WSW of Puerto Madero (2026-07-17, 18.6 km) and an M6.4 86 km WSW of Puerto Madero (2026-07-17, 10 km). The Puerto Madero/Chiapas swarm stayed the dominant feature (35 events to 2026-07-22, still generating shocks a week after the mainshock, no fresh major); Mexico held the count lead at 39, Indonesia 12, southern Mid-Atlantic Ridge 11, Chile 8. Deepest event updated to a 550.1 km Maumere, Indonesia focus as the 625.6 km Fiji foci aged out; 77 of 155 shocks shallow ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-07-24 — daily-ingest synthesis (2026-W30): absorbed the 2026-07-24 USGS pull; the rolling window to 2026-07-24 held at 155 M4.5+ (54 M5+, 2 M6+, 1 M7+ — the M5+ tally eased from 59). Composition unchanged: both remaining majors stay on the Chiapas trend — the carried M7.3 58 km WSW of Puerto Madero (2026-07-17, 18.6 km) and the M6.4 86 km WSW of Puerto Madero (2026-07-17, 10 km), now a full week old and aging toward the trailing edge with no fresh major on the pull. The Chiapas swarm grew to 43 events (2026-07-17 through 2026-07-23), still live six days after the mainshock; an M5.8 130 km W of Ternate, Indonesia (2026-07-23, 49 km) is the fresh sub-M6 leader and lifted Indonesia to 15 on the count. Mexico held the count lead at 41; deepest event held at the 550.1 km Maumere focus; 71 of 155 shocks shallow ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-07-25 — daily-ingest synthesis (2026-W30): absorbed the 2026-07-25 USGS pull; the rolling window to 2026-07-25 eased to 133 M4.5+ (44 M5+, 1 M6+, 0 M7+ — from 155/54/2/1). The anticipated roll-off arrived: the M7.3 58 km WSW and M6.4 86 km WSW of Puerto Madero, Mexico (both 2026-07-17) aged past the seven-day trailing edge, taking M7+ to zero and leaving a single M6+ — a fresh M6.0 82 km W of Sola, Vanuatu (2026-07-24, 44.6 km) that caps a new 8-event Vanuatu offshore swarm (Sola/Port-Olry), the cycle's dominant cluster. Fresh M5.7s struck 292 km SSE of Ushuaia, Argentina and 49 km W of Turangi, New Zealand. Mexico's count lead narrowed to 20 (from 41) as the Chiapas sequence decayed, Indonesia rose to 18; deepest event held at the 550.1 km Maumere focus; 61 of 133 shocks shallow ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-07-30 — daily-ingest synthesis (2026-W31): absorbed the 2026-07-26 through 2026-07-30 USGS pulls (the prior curator commit had sat un-pushed for five days behind the live L1); the rolling window to 2026-07-30 rose to 140 M4.5+ (66 M5+, 2 M6+, 0 M7+ — from 133/44/1/0). The new headline is a shallow **M6.8 "2026 Uto, Japan Earthquake"** (Kyushu, 2026-07-28, 10 km), now the window's strongest event, capping a Kyushu Tsunagi/Honmachi sequence; a fresh 14-event "south of Tonga" swarm became the dominant cluster and a Qinghai (Oula Xiuma) China sequence added M5.8/M5.7 shocks, lifting M5+ sharply from 44 to 66. The carried Vanuatu M6.0 (07-24) held as its swarm decayed; deepest event moved to a 575.1 km south-of-Fiji focus (from 550.1 km Maumere); 80 of 140 shocks shallow ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
- 2026-08-01 — daily-ingest synthesis (2026-W31): absorbed the 2026-08-01 USGS pull; the rolling window to 2026-08-01 held near flat at 138 M4.5+ (66 M5+, 1 M6+, 0 M7+ — from 137/69/2/0). The anticipated roll-off arrived: the carried M6.0 82 km W of Sola, Vanuatu (2026-07-24) aged past the seven-day trailing edge, halving the M6+ count to one and leaving the M6.8 "2026 Uto, Japan Earthquake" (2026-07-28) the sole major and still the window's strongest. The south-of-Tonga swarm stayed the dominant cluster (15 events) and Japan held 10 on the Kyushu sequence; the M5.8–M5.9 band spread across Micronesia (Colonia M5.9), the Kermadecs, Mexico (Brisas M5.9), Kamchatka, Qinghai China and Alaska. Deepest event deepened to a 581.0 km Fiji-region focus; 78 of 138 shocks shallow ≤15 km. Rewrote the at-a-glance, largest-events, clustering, depth and reading sections. Observed-only framing held ([[earthquakes]]).
